v20050314 copy 2005 Purdue University 1
Mitigate the Downside Risks of Second-Year Corn
RL (Bob) NielsenPurdue University AgronomyEmail rnielsenpurdueedu
KingCorn wwwkingcornorgChat lsquon Chew Cafe wwwkingcornorgcafe
Summary article available online at wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 2v20050314
Second-year cornhellipFear amp uncertainty of soy rust has ldquoadded fuel to the firerdquo for some growers who were already considering 2nd-year corn for economic reasons
Economics vary greatly depending on assumptions used in the calculations
Yield drag crop prices variable costs uncertain need for soy fungicide or insecticide
copy 2005 Purdue University 3v20050314
Short-run vs Long-haulhellipSingle-year comparison may indeed favor 2nd-year corn over rotation soy
Especially if applications of soy fungicides or insecticides are anticipated
Long-run comparison favors cornsoy when corncorn return is less than the average of cornsoy and soycorn returns
Work w own crop budgets if possiblehellip
copy 2005 Purdue University 4v20050314
Illinois crop budgeting toolhellipComputes budget for per-acre returns for up to 4 different crops
Requires you already know per acre costsDownload (free registration) from Univ of Illinois ldquofarmdocrdquo Web page that lists numerous such spreadsheet tools
Look under ldquoFarm Managementrdquo section
wwwfarmdocuiucedufasttoolsindexhtml
copy 2005 Purdue University 5v20050314
Record-keeping toolshellipldquoWinMaxrdquo software from Purdue
wwwagrypurdueedumax (free)ldquoFarm Tracrdquo software from Farm Works
wwwfarmworkscom (not free)Numerous other software programs
Googletrade agricultural software directory
copy 2005 Purdue University 6v20050314
AgronomicallyhellipWe cannot support 2nd-yr corn becausehellip
Yields of corncorn are at least 6 to 10 less than cornsoy
Worse if risks are not managed wiselyHigher risk of some diseases amp insectsHigher nitrogen fertilizer requirementAlters time management issueshellip
eg sidedressing timely harvest
copy 2005 Purdue University 7v20050314
But if yoursquore gonna do ithellipThen consider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
copy 2005 Purdue University 8v20050314
Fertility issueshellipHigher N requirement (~ 50 more lbs Nac)
Cost amp availability may be issuesIf sidedressing N more days will be required to cover more corn acresShort-term P amp K issues not serious
Over time corncorn will remove more soil P than cornsoy
copy 2005 Purdue University 9v20050314
High nitrogen fertilizer costshellipShould encourage growers to critically evaluate their nitrogen fertility program
Nitrogen application ratesNitrogen use efficiency (NUE)
Application timing amp placement soils climate farming logistics
N source (product)Cost availability NUE farming logistics
copy 2005 Purdue University 10v20050314
Nitrogen application rateshellipTraditionally linked to field productivity
Yield goals based on historical yieldsFive-year running average probably okay
Corn following soybean Aim for about 1 lb of N per bushel
Corn following corn or wheat Aim for about 12 lbs per bushel
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 2v20050314
Second-year cornhellipFear amp uncertainty of soy rust has ldquoadded fuel to the firerdquo for some growers who were already considering 2nd-year corn for economic reasons
Economics vary greatly depending on assumptions used in the calculations
Yield drag crop prices variable costs uncertain need for soy fungicide or insecticide
copy 2005 Purdue University 3v20050314
Short-run vs Long-haulhellipSingle-year comparison may indeed favor 2nd-year corn over rotation soy
Especially if applications of soy fungicides or insecticides are anticipated
Long-run comparison favors cornsoy when corncorn return is less than the average of cornsoy and soycorn returns
Work w own crop budgets if possiblehellip
copy 2005 Purdue University 4v20050314
Illinois crop budgeting toolhellipComputes budget for per-acre returns for up to 4 different crops
Requires you already know per acre costsDownload (free registration) from Univ of Illinois ldquofarmdocrdquo Web page that lists numerous such spreadsheet tools
Look under ldquoFarm Managementrdquo section
wwwfarmdocuiucedufasttoolsindexhtml
copy 2005 Purdue University 5v20050314
Record-keeping toolshellipldquoWinMaxrdquo software from Purdue
wwwagrypurdueedumax (free)ldquoFarm Tracrdquo software from Farm Works
wwwfarmworkscom (not free)Numerous other software programs
Googletrade agricultural software directory
copy 2005 Purdue University 6v20050314
AgronomicallyhellipWe cannot support 2nd-yr corn becausehellip
Yields of corncorn are at least 6 to 10 less than cornsoy
Worse if risks are not managed wiselyHigher risk of some diseases amp insectsHigher nitrogen fertilizer requirementAlters time management issueshellip
eg sidedressing timely harvest
copy 2005 Purdue University 7v20050314
But if yoursquore gonna do ithellipThen consider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
copy 2005 Purdue University 8v20050314
Fertility issueshellipHigher N requirement (~ 50 more lbs Nac)
Cost amp availability may be issuesIf sidedressing N more days will be required to cover more corn acresShort-term P amp K issues not serious
Over time corncorn will remove more soil P than cornsoy
copy 2005 Purdue University 9v20050314
High nitrogen fertilizer costshellipShould encourage growers to critically evaluate their nitrogen fertility program
Nitrogen application ratesNitrogen use efficiency (NUE)
Application timing amp placement soils climate farming logistics
N source (product)Cost availability NUE farming logistics
copy 2005 Purdue University 10v20050314
Nitrogen application rateshellipTraditionally linked to field productivity
Yield goals based on historical yieldsFive-year running average probably okay
Corn following soybean Aim for about 1 lb of N per bushel
Corn following corn or wheat Aim for about 12 lbs per bushel
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 3v20050314
Short-run vs Long-haulhellipSingle-year comparison may indeed favor 2nd-year corn over rotation soy
Especially if applications of soy fungicides or insecticides are anticipated
Long-run comparison favors cornsoy when corncorn return is less than the average of cornsoy and soycorn returns
Work w own crop budgets if possiblehellip
copy 2005 Purdue University 4v20050314
Illinois crop budgeting toolhellipComputes budget for per-acre returns for up to 4 different crops
Requires you already know per acre costsDownload (free registration) from Univ of Illinois ldquofarmdocrdquo Web page that lists numerous such spreadsheet tools
Look under ldquoFarm Managementrdquo section
wwwfarmdocuiucedufasttoolsindexhtml
copy 2005 Purdue University 5v20050314
Record-keeping toolshellipldquoWinMaxrdquo software from Purdue
wwwagrypurdueedumax (free)ldquoFarm Tracrdquo software from Farm Works
wwwfarmworkscom (not free)Numerous other software programs
Googletrade agricultural software directory
copy 2005 Purdue University 6v20050314
AgronomicallyhellipWe cannot support 2nd-yr corn becausehellip
Yields of corncorn are at least 6 to 10 less than cornsoy
Worse if risks are not managed wiselyHigher risk of some diseases amp insectsHigher nitrogen fertilizer requirementAlters time management issueshellip
eg sidedressing timely harvest
copy 2005 Purdue University 7v20050314
But if yoursquore gonna do ithellipThen consider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
copy 2005 Purdue University 8v20050314
Fertility issueshellipHigher N requirement (~ 50 more lbs Nac)
Cost amp availability may be issuesIf sidedressing N more days will be required to cover more corn acresShort-term P amp K issues not serious
Over time corncorn will remove more soil P than cornsoy
copy 2005 Purdue University 9v20050314
High nitrogen fertilizer costshellipShould encourage growers to critically evaluate their nitrogen fertility program
Nitrogen application ratesNitrogen use efficiency (NUE)
Application timing amp placement soils climate farming logistics
N source (product)Cost availability NUE farming logistics
copy 2005 Purdue University 10v20050314
Nitrogen application rateshellipTraditionally linked to field productivity
Yield goals based on historical yieldsFive-year running average probably okay
Corn following soybean Aim for about 1 lb of N per bushel
Corn following corn or wheat Aim for about 12 lbs per bushel
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 4v20050314
Illinois crop budgeting toolhellipComputes budget for per-acre returns for up to 4 different crops
Requires you already know per acre costsDownload (free registration) from Univ of Illinois ldquofarmdocrdquo Web page that lists numerous such spreadsheet tools
Look under ldquoFarm Managementrdquo section
wwwfarmdocuiucedufasttoolsindexhtml
copy 2005 Purdue University 5v20050314
Record-keeping toolshellipldquoWinMaxrdquo software from Purdue
wwwagrypurdueedumax (free)ldquoFarm Tracrdquo software from Farm Works
wwwfarmworkscom (not free)Numerous other software programs
Googletrade agricultural software directory
copy 2005 Purdue University 6v20050314
AgronomicallyhellipWe cannot support 2nd-yr corn becausehellip
Yields of corncorn are at least 6 to 10 less than cornsoy
Worse if risks are not managed wiselyHigher risk of some diseases amp insectsHigher nitrogen fertilizer requirementAlters time management issueshellip
eg sidedressing timely harvest
copy 2005 Purdue University 7v20050314
But if yoursquore gonna do ithellipThen consider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
copy 2005 Purdue University 8v20050314
Fertility issueshellipHigher N requirement (~ 50 more lbs Nac)
Cost amp availability may be issuesIf sidedressing N more days will be required to cover more corn acresShort-term P amp K issues not serious
Over time corncorn will remove more soil P than cornsoy
copy 2005 Purdue University 9v20050314
High nitrogen fertilizer costshellipShould encourage growers to critically evaluate their nitrogen fertility program
Nitrogen application ratesNitrogen use efficiency (NUE)
Application timing amp placement soils climate farming logistics
N source (product)Cost availability NUE farming logistics
copy 2005 Purdue University 10v20050314
Nitrogen application rateshellipTraditionally linked to field productivity
Yield goals based on historical yieldsFive-year running average probably okay
Corn following soybean Aim for about 1 lb of N per bushel
Corn following corn or wheat Aim for about 12 lbs per bushel
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 5v20050314
Record-keeping toolshellipldquoWinMaxrdquo software from Purdue
wwwagrypurdueedumax (free)ldquoFarm Tracrdquo software from Farm Works
wwwfarmworkscom (not free)Numerous other software programs
Googletrade agricultural software directory
copy 2005 Purdue University 6v20050314
AgronomicallyhellipWe cannot support 2nd-yr corn becausehellip
Yields of corncorn are at least 6 to 10 less than cornsoy
Worse if risks are not managed wiselyHigher risk of some diseases amp insectsHigher nitrogen fertilizer requirementAlters time management issueshellip
eg sidedressing timely harvest
copy 2005 Purdue University 7v20050314
But if yoursquore gonna do ithellipThen consider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
copy 2005 Purdue University 8v20050314
Fertility issueshellipHigher N requirement (~ 50 more lbs Nac)
Cost amp availability may be issuesIf sidedressing N more days will be required to cover more corn acresShort-term P amp K issues not serious
Over time corncorn will remove more soil P than cornsoy
copy 2005 Purdue University 9v20050314
High nitrogen fertilizer costshellipShould encourage growers to critically evaluate their nitrogen fertility program
Nitrogen application ratesNitrogen use efficiency (NUE)
Application timing amp placement soils climate farming logistics
N source (product)Cost availability NUE farming logistics
copy 2005 Purdue University 10v20050314
Nitrogen application rateshellipTraditionally linked to field productivity
Yield goals based on historical yieldsFive-year running average probably okay
Corn following soybean Aim for about 1 lb of N per bushel
Corn following corn or wheat Aim for about 12 lbs per bushel
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 6v20050314
AgronomicallyhellipWe cannot support 2nd-yr corn becausehellip
Yields of corncorn are at least 6 to 10 less than cornsoy
Worse if risks are not managed wiselyHigher risk of some diseases amp insectsHigher nitrogen fertilizer requirementAlters time management issueshellip
eg sidedressing timely harvest
copy 2005 Purdue University 7v20050314
But if yoursquore gonna do ithellipThen consider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
copy 2005 Purdue University 8v20050314
Fertility issueshellipHigher N requirement (~ 50 more lbs Nac)
Cost amp availability may be issuesIf sidedressing N more days will be required to cover more corn acresShort-term P amp K issues not serious
Over time corncorn will remove more soil P than cornsoy
copy 2005 Purdue University 9v20050314
High nitrogen fertilizer costshellipShould encourage growers to critically evaluate their nitrogen fertility program
Nitrogen application ratesNitrogen use efficiency (NUE)
Application timing amp placement soils climate farming logistics
N source (product)Cost availability NUE farming logistics
copy 2005 Purdue University 10v20050314
Nitrogen application rateshellipTraditionally linked to field productivity
Yield goals based on historical yieldsFive-year running average probably okay
Corn following soybean Aim for about 1 lb of N per bushel
Corn following corn or wheat Aim for about 12 lbs per bushel
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 7v20050314
But if yoursquore gonna do ithellipThen consider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
copy 2005 Purdue University 8v20050314
Fertility issueshellipHigher N requirement (~ 50 more lbs Nac)
Cost amp availability may be issuesIf sidedressing N more days will be required to cover more corn acresShort-term P amp K issues not serious
Over time corncorn will remove more soil P than cornsoy
copy 2005 Purdue University 9v20050314
High nitrogen fertilizer costshellipShould encourage growers to critically evaluate their nitrogen fertility program
Nitrogen application ratesNitrogen use efficiency (NUE)
Application timing amp placement soils climate farming logistics
N source (product)Cost availability NUE farming logistics
copy 2005 Purdue University 10v20050314
Nitrogen application rateshellipTraditionally linked to field productivity
Yield goals based on historical yieldsFive-year running average probably okay
Corn following soybean Aim for about 1 lb of N per bushel
Corn following corn or wheat Aim for about 12 lbs per bushel
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 8v20050314
Fertility issueshellipHigher N requirement (~ 50 more lbs Nac)
Cost amp availability may be issuesIf sidedressing N more days will be required to cover more corn acresShort-term P amp K issues not serious
Over time corncorn will remove more soil P than cornsoy
copy 2005 Purdue University 9v20050314
High nitrogen fertilizer costshellipShould encourage growers to critically evaluate their nitrogen fertility program
Nitrogen application ratesNitrogen use efficiency (NUE)
Application timing amp placement soils climate farming logistics
N source (product)Cost availability NUE farming logistics
copy 2005 Purdue University 10v20050314
Nitrogen application rateshellipTraditionally linked to field productivity
Yield goals based on historical yieldsFive-year running average probably okay
Corn following soybean Aim for about 1 lb of N per bushel
Corn following corn or wheat Aim for about 12 lbs per bushel
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 9v20050314
High nitrogen fertilizer costshellipShould encourage growers to critically evaluate their nitrogen fertility program
Nitrogen application ratesNitrogen use efficiency (NUE)
Application timing amp placement soils climate farming logistics
N source (product)Cost availability NUE farming logistics
copy 2005 Purdue University 10v20050314
Nitrogen application rateshellipTraditionally linked to field productivity
Yield goals based on historical yieldsFive-year running average probably okay
Corn following soybean Aim for about 1 lb of N per bushel
Corn following corn or wheat Aim for about 12 lbs per bushel
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 10v20050314
Nitrogen application rateshellipTraditionally linked to field productivity
Yield goals based on historical yieldsFive-year running average probably okay
Corn following soybean Aim for about 1 lb of N per bushel
Corn following corn or wheat Aim for about 12 lbs per bushel
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
Assumes a 30 lb N credit for previous crop soybean A 50 lb N credit would lower rate to ~ 09 lb N per bu
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 11v20050314
Bottom line on N ratesUse realistic yield goals (not record yields)Credit all the N you can from nitrogen in starter fertilizer weed lsquon feed herbicide applrsquons spring plowdown ammoniated phosphates manure applrsquonsGiven high N prices consider shaving rates up to 10 if cash flow or N supply is tight
Esp if using higher priced urea or UAN
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 12v20050314
More N management adviceIf cash flow or N supply is limited
Apply some N to all corn fields rather than full rate on some and skimping on others
Because greatest yield response comes from first N lbs applied less from last lbs
Concentrate on achieving better nitrogen use efficiencyhellip
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 13v20050314
Nitrogen use efficiencyhellipSome of the fertilizer nitrogen we apply to a field is lost to the environment hellip
In other words not all of the nitrogen applied to a field is used by the crop
Nitrogen use efficiency (NUE) is the balance between that used by plants vs that lost to the environment
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 14v20050314
NUE is influenced byhellipThe efficiency of the ldquophotosynthetic factoryrdquo (ie the plant)
Minimal stress = Maximum ldquofactoryrdquo efficiency 2004 record yields were classic example of high yields at high NUE
The occurrence amp severity of nitrogen loss within the nitrogen cycle
Volatilization leaching denitrification
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 15v20050314
Stand establishment issuesGreater residues of corncorn often delay soil warmup amp drying in spring can also create havoc w planter if no-till
Target better-drained fields for corncornTillage if practical to manage residueRow cleaners or similar no-till planter gadgetsAvoid planting excessively earlyResponse to starter more likely
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 16v20050314
Success w starter fertilizerhellipDepends on your ability to maximizehellip
Probability of getting a response andhellipPotential size of the response if it occurs
Your goal should be to achieve the biggest bang for the fertilizer dollar
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 17v20050314
Starter fert decisionshellip
High soil test P amp K + warm seedbed
Probability of yield response to starter is low andhellipSize of expected response is low so hellip Little yield risk if you decide to forego the use of starter
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 18v20050314
Starter fert decisionshellip
High soil test P amp K but cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P amp K is low buthellipProbability of yield response to starter N is high sohellipUse starter N and aim for no less than 20 lbs N per acre
Minimum of 20 lbs N optimizes the probability and size of a starter response
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 19v20050314
Starter fert decisionshellip
Low soil test P + cold ldquocrappyrdquo conditions for germination and seedling growth
Probability of yield response to starter P and N is high sohellipApply N + P starter mix but still aim for no less than 20 lbs starter N per acre
But recognize that 10-34-0 is not cheaphellip
bull $279ton (Jan rsquo05) = $140lb N = $28ac for 20 lbs N
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 20v20050314
Disease risksSome seedling blight diseases thrive in cool wet soils early in the season
Avoid excessively early planting in poorly drained soils
Some corn diseases survive on non-decomposed corn plant residues
Especially northern corn leaf blight gray leaf spot Diplodia ear rot
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 21v20050314
Northern corn leaf blightConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueWet cloudy weather Temperatures ranging from 65 ndash 80 F
Reasons for recent prevalence uncertainImage Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 22v20050314
Gray leaf spotConducive conditions
Susceptible hybridsContinuous cornDisease inoculum
Old corn residueHigh humidityExtended periods of leaf wetnessTemperatures ranging from 70 ndash 85 F
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 23v20050314
Diplodia ear rotsReasons for recent prevalence uncertainInfection occurs at ear shank through base of the husk leaves or on silks Conducive conditions
Susceptible hybridsDisease inoculumCool wet weather during late whorl through early grain fill
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 24v20050314
Break the disease trianglehellip
Avoid corn following cornAvoid excessively early plantingAvoid high residue tillage practices
Especially corncorn + no-tillAvoid susceptible hybrids
Work closely w seed reps
Image Source httpwwwsoybeanrustinfocomdetailsdetailsasp
Growers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangleGrowers can most easily impact the ldquohostrdquo and ldquoenvironmentrdquo sides of the disease triangle
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 25v20050314
Insect issueshellipPrimary insect to consider in short-term corn after corn is corn rootworm
Consider judicious use of soil insecticide SAI or transgenic Bt hybrids
Corn borer likely not worse in 2nd-yr corn but pressure could elevate in lengthier continuous corn systems
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 26v20050314
CRW control optionshellipMost consistent control
Granular insecticidesBt-RW hybrids (transgenics)
Though some questionsLess consistent control
Liquid insecticidesHigh rate SAI Image Source RLNielsen copy Purdue Univ
These differences are most pronounced where rootworm pressure is severe (high populations)
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 27v20050314
Seed-Applied Insecticides (SAI)Newer insecticide class Neonicotinoids
Ponchotrade Cruiser trade GauchotradeSystemic to roots amp new leaves
Targeted towardshellipSecondary soil insects (low rate formulations)Corn rootworm (high rate formulations)
Pre-applied to seed by seed companySometimes must be requested w seed order~ $4 ndash $6 per acre (low rate formulations)~ $18 ndash 20 per acre (high rate formulations)
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 28v20050314
SAI efficacy on secondary insects
Purdue Entomology opinion on efficacy of low rate SAIhellip
Seedcorn maggot ~ ExcellentWireworm ~ GoodWhite grub ~ FairBlack cutworm ~ Fair
Source of Ratings J Obermeyer L Bledsoe (Purdue Entomology)Wireworm Image Source wwwipmuiucedufieldcropsinsectswirewormindexhtmlSCM Image Source httpwwwukyeduAgricultureEntomologyentfactsfldcropsef120htm
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 29v20050314
A form of ldquocrop insurancerdquohellipBecause WW amp SCM do not consistentlyoccur at damaging levels SAI should be considered ldquocrop insurancerdquo with ldquoinsurance premiumsrdquo of ~ $4 - $6ac
Seek the biggest ldquobangrdquo for this input withEarly planting (high risk cool wet soils)Fields with known history or high risk of wireworm or seedcorn maggots
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
Wireworms Grassy weed areas grass sod
Seedcorn maggot Decaying vegetation manures
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 30v20050314
Hybrid selectionGreater emphasis on hybrid traits important to corncorn systems
Seedling vigorDisease toleranceStalk amp root strengthOverall plant stalk and root healthOverall stress tolerance
Image Source RLNielsen copy Purdue Univ
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 31v20050314
Choosing hybrids wiselyhellipNo such thing as a perfect hybrid or else there wouldnrsquot be so many hybrids for sale in the marketplace
Choosing hybrids wisely is not easyChoosing hybrids wisely requires a lot of effort on your part
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 32v20050314
Bottom lineThere is no single method that is easy or perfect for selecting corn hybrids that will perform consistently well in your farming operation Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework ldquomassagingrdquo the data to make sense out of it
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 33v20050314
Dumb hybrid decision-making Simply because itrsquos cheapSimply because itrsquos newSimply because itrsquos biotechSimply because itrsquos the one the company has the most bags of in the warehouseSimply because itrsquos genetically different from the other one you boughtSimply because you trust the seed rep
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 34v20050314
Harvest timing issueshellipMore corn acres translates to a longer corn harvest season
Some corn fields will remain standing (or not) later into the fall than usualScout fields beginning late August for stalk rot development or simply weak stalks
Prioritize harvest of high risk fields if necessary
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
copy 2005 Purdue University 35v20050314
In summaryhellipConsider how to mitigate the downside risks of corn following corn
Fertility especially nitrogenStand establishment issuesDiseases amp insectsHybrid selection amp availabilityHarvest timing issues
wwwkingcornorgnewsarticles04CornCorn-1222html
