A GRONOMY N EWS A research - based publication from the University of Maryland Extension Agronomy Team Paul Goeringer, Agriculture Law Legal Specialist University of Maryland Extension Dicamba Update: What Is Going On In the Ninth Circuit & What Is Going On With the Driſt Class Acon extension.umd.edu VOLUME 11, ISSUE 5 INSIDE THIS ISSUE: Small Grain Variety Trials 2 Corn Earworm Pressure 3 Organic Cover Crop Terminaon Research 4 4R Field Day 5 Unsolicited Seed Packages 6 Phase Out of Chlorpyrifos 6 Woodland Stewardship Programs 7 Mid-Atlanc Crop Management School 8 CFAP Applicaon Reminder 8 August Insect Scoung 9 Updated Ag Legal Directory 9 Heat & Drought-Stressed Soybeans 10 Scout for Silk-Clipping Insects in Corn 11 Keys for Opmum Forage Establishment 13 Tall Fescue Field Day 14 Pescide Container Recycling Dates 15 Crop Talk Webinar 15 Weather Outlook 16 Regional Crop Reports 18 The University of Maryland is an Equal Opportunity Employer and Offers Equal Access Programs AUGUST 2020 This is not a substute for legal advice See here for the site’s reposng policy. Dicamba has been back in the news lately in several areas. EPA recently moved to cancel registraons for three dicamba products, XtendiMax®, Engenia®, and FeXapan®, based on a ruling in the Ninth Circuit. Growers [had] ll the end of July 2020 to use exisng stocks. And Bayer, the parent company of Monsanto, recently announced selement of around $400 million for class-acon lawsuits filed against possible driſt damage caused by the company’s XtendiMax product. Although details of that selement will not be known for a while, let’s step back and get a sense of what this means for growers. What are the dicamba driſt lawsuits about? Producers experiencing dicamba driſt damage brought the current In re Dicamba Herbicides Ligaon against the manufactures of the dicamba-based herbicides XtendiMax and Engenia. With the federal claims, the plainffs argue that Monsanto and BASF Corporaon violated § 1125(a) of the Lanham Act in markeng both XtendiMax and Engenia dicamba- based herbicides. The plainffs also allege that state claims focused on negligence claims in product design, failure to warn of negligence in the design, failure to warn of the dangers, and poor training sales of representaves for the two dicamba-based herbicides. Only one of the federal lawsuits has gone to trial on similar claims in In re Dicamba Herbicides Ligaon. A federal jury in Bader Farms, Inc. v. Monsanto Co. awarded a Missouri peach grower $265 million in damages, $15 million in actual damages, and $250 million punive damages. The defendants are currently appealing this decision. What is in the selement? The exact terms of the selement are currently unknown. The plainffs and defendants have agreed in principle to sele claims of yield losses due to dicamba damage from 2015 to 2020. About $300 million of the selement will cover specific losses to soybean growers during that period. Another $100 million of the selement will go towards non-soybean damage and include the plainffs' aorneys' fees. Who will be eligible? What sll is not known is how broad the eligibility will be. We do not know if this will be naonwide or limited to the class acon lawsuit states. As menoned above, we currently know the selement will cover yield losses due to driſt damage from 2015 to 2020. We will have to wait for the final
Transcript
AGRONOMY NEWS A research-based publication from the University of Maryland Extension Agronomy Team
Paul Goeringer, Agriculture Law Legal Specialist University of Maryland Extension
Dicamba Update: What Is Going On In the Ninth Circuit & What Is Going On With the Drift Class Action
extension.umd.edu
VOLUME 11, ISSUE 5
INSIDE THIS ISSUE:
Small Grain Variety Trials 2
Corn Earworm Pressure 3
Organic Cover Crop Termination Research
4
4R Field Day 5
Unsolicited Seed Packages 6
Phase Out of Chlorpyrifos 6
Woodland Stewardship Programs
7
Mid-Atlantic Crop Management School
8
CFAP Application Reminder
8
August Insect Scouting 9
Updated Ag Legal Directory
9
Heat & Drought-Stressed Soybeans
10
Scout for Silk-Clipping Insects in Corn
11
Keys for Optimum Forage Establishment
13
Tall Fescue Field Day 14
Pesticide Container Recycling Dates
15
Crop Talk Webinar 15
Weather Outlook 16
Regional Crop Reports 18
The University of Maryland is an Equal Opportunity Employer and Offers Equal Access Programs
AUGUST 2020
This is not a substitute for legal advice See here for the site’s reposting policy.
Dicamba has been back in the news lately in several areas. EPA recently moved to cancel registrations for three dicamba products, XtendiMax®, Engenia®, and FeXapan®, based on a ruling in the Ninth Circuit. Growers [had] till the end of July 2020 to use existing stocks. And Bayer, the parent company of Monsanto, recently announced settlement of around $400 million for class-action lawsuits filed against possible drift damage caused by the company’s XtendiMax product. Although details of that settlement will not be known for a while, let’s step back and get a sense of what this means for growers.
What are the dicamba drift lawsuits about?
Producers experiencing dicamba drift damage brought the current In re Dicamba Herbicides Litigation against the manufactures of the dicamba-based herbicides XtendiMax and Engenia. With the federal claims, the plaintiffs argue that Monsanto and BASF Corporation violated § 1125(a) of the Lanham Act in marketing both XtendiMax and Engenia dicamba-based herbicides. The plaintiffs also allege that state claims focused on negligence claims in product design, failure to warn of negligence in the design, failure to warn of the dangers, and poor training sales of
representatives for the two dicamba-based herbicides.
Only one of the federal lawsuits has gone to trial on similar claims in In re Dicamba Herbicides Litigation. A federal jury in Bader Farms, Inc. v. Monsanto Co. awarded a Missouri peach grower $265 million in damages, $15 million in actual damages, and $250 million punitive damages. The defendants are currently appealing this decision.
What is in the settlement?
The exact terms of the settlement are currently unknown. The plaintiffs and defendants have agreed in principle to settle claims of yield losses due to dicamba damage from 2015 to 2020. About $300 million of the settlement will cover specific losses to soybean growers during that period. Another $100 million of the settlement will go towards non-soybean damage and include the plaintiffs' attorneys' fees.
Who will be eligible?
What still is not known is how broad the eligibility will be. We do not know if this will be nationwide or limited to the class action lawsuit states. As mentioned above, we currently know the settlement will cover yield losses due to drift damage from 2015 to 2020. We will have to wait for the final
University of Maryland Small Grain Variety Trial Reports Dr. Vijay Tiwari & Dr. Nidhi Rawat
University of Maryland, Department of Plant Science & Landscape Architecture
settlement agreement to be announced to get more details on eligibility.
How will you apply?
How to apply is another good question for which we currently do not have an answer. When the final settlement agreement is announced we will get a sense of the timeline for eligibility. Since this settlement includes the 2020 crop year, we can assume that signup would not even start until after completing the 2020 harvest to allow time to determine potential damage. Because the settlement is based on yield damage, we can assume you will need to submit crop insurance documentation or have calibrated yield monitoring data to verify this yield loss due to dicamba drift damage.
How does this relate to the on-going lawsuit in the Ninth Circuit Court of Appeals?
The recently announced settlement and the lawsuit in the Ninth Circuit Court of Appeals are related in the sense that they both include many of the same dicamba-based herbicide products, and that is about it. As
mentioned earlier, the class action settlement is based around federal claims that the defendants violated the Lanham Act and state law-based tort claims. The claims in the Ninth Circuit are related to EPA's approval of the 2018 registration for BASF, Bayer, and Corteva dicamba-based herbicide products.
Based on the court's vacatur of that registration, EPA has moved to cancel the three dicamba-based herbicides', XtendiMax, Engenia, and FeXapan, registrations. Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA only has authority to either cancel or suspend federal pesticide registrations. With a suspension or cancellation, EPA can set the conditions on which canceled or suspended pesticides can be sold, distributed, or used.
Looking forward, the 2018 registrations for these three products would have expired later this year. EPA will need to consider the Ninth Circuit's ruling in the process to reregister these three products. We will have to watch this process to see if the products are reregistered in time for the 2021 growing season.
Results from the 2020 University of Maryland small grain variety trials are posted online or hard copies may be requested through your Extension office. Each year, seed companies submit seed varieties for testing, so keep in mind that this is not an exhaustive list of wheat and barley varieties, but provides useful information regarding several varieties tested across five locations in Maryland. These replicated plots provide information on yield, test weight and other plant characteristics.
When reading the report it is important to factor in the statistical information provided; do not simply look at the numerically highest yielding variety and dismiss the rest of the data. For example, while Dyna-Gro WX20731 achieved numerically the highest statewide average yield (101.5 bu/a) in the test, it did not differ from 13 other varieties in the test (down to 93.7 bu/a). In other words, these 14 varieties are likely to perform similarly and we can say with a high degree of certainty that they yield the same under similar conditions. For more information regarding the interpretation variety trial data, see this Extension Fact Sheet: https://
Due to COVID-19 closing the testing lab, DON vomitoxin data for the tested wheat varieties have yet to be processed. In the meantime, ratings for Fusarium head blight (FHB) symptoms (reported as FHB index) are provided in the report. Please note that the FHB Index based on visual symptoms of the disease is coming from a high disease pressure misted nursery set up at Beltsville without a fungicide application. Visual symptoms may not necessarily have high correlation with DON content values; in other words, a variety can show few symptoms of FHB (low FHB index score), but have very high levels of DON in the grain and vice- versa. DON results will be provided as soon as they are available.
If you have any questions regarding these data, reach out to Dr. Vijay Tiwari ([email protected], 301-405-1730) or Dr. Nidhi Rawat ([email protected], 301 405-9744).
Corn Earworm Pressure Varying Regionally—Make Sure to Scout Kelly Hamby1, Maria Cramer1, Galen Dively1, Sarah Hirsh2, Andrew Kness2
Alan Leslie2, Kelly Nichols2, Emily Zobel2, and David Owens3 1University of Maryland, Department of Entomology | 2University of Maryland Extension
3University of Delaware Extension
A few hot spots where corn earworm (also known as tomato fruitworm, soybean podworm, and sorghum headworm) activity is starting to rise have been identified in central Maryland and Delaware. The warm 2019-2020 winter allowed for overwintering in our area, and some parts of the state experienced a higher than normal first flight in early June. The warm
weather through June and July made for speedy development and earlier activity for the second summer generation. Because corn earworm has developed resistance to most Bt hybrids, significantly more adult moths are emerging compared to levels a decade ago. Some areas continue to capture few moths and are experiencing low pressure, while others have been experiencing moderate pressure that may continue to increase towards heavy pressure (>65 moths captured per 5 days). Captures for select sites in Maryland and Delaware are pictured below, and values within the gray box indicate low pressure (<7 for weekly captures, and <5 for four to five day captures).
Although corn earworm prefer fresh corn silks for egg laying, they will lay eggs on wilted and brown silks if
the plants remain green and unstressed. As corn matures further over the next several weeks, corn earworm activity will shift to other host plants including soybeans and vegetables. See last summer’s articles for scouting and management recommendations in vegetables as well as sorghum and soybeans.
Podworm outbreaks have historically occurred in growing seasons where the corn crop was drought and heat stressed, with corn senescing earlier than normal. However, narrow row spacing in soybeans makes the plants less attractive to female moths and increases the likelihood that fungal pathogens will infect the larvae. Therefore, it is important to scout bean fields, especially paying attention to those fields with a more open canopy in areas where the nearby maturing corn is no longer attractive to earworm moths. North Carolina State University has produced a helpful economic threshold calculator for podworm in soybean: https://www.ces.ncsu.edu/wp-content/uploads/2017/08/CEW-calculator-v0.006.html
Acknowledgements: Corn earworm trapping efforts in were supported by the Crop Protection and Pest Management Program [grant numbers 2017-70006-27171 and 2017-70006-27286] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.
Preliminary Trial of Clove Oil-Based Herbicide for Cover Crop Termination in Organic Farming
Ray Weil1, Kevin Conover2, Mia Godbey1 1Dept of Environmental Science and Technology and 2Central Maryland Research and Education Center
University of Maryland, College of Agriculture and Natural Resources
Weed control is almost invariably cited as one of the biggest challenges for the organic production of grain crops. Synthetic herbicides cannot be used in organic farming, leaving tillage as the main weed control option. Tillage is also the main method of terminating cover crops in organic farming, although roller-crimping can work under some circumstances. The lack of chemical means of weed control makes low disturbance or no-till organic farming extremely difficult if not impossible on a commercial scale.
This spring we conducted a preliminary trial to access the efficacy of a new organically-approved herbicide called Weed Slayer® (based on Eugenol, an essential oil from cloves, molasses, and a biological surfactant mixture). This product comes in two parts, the Clove Oil product, and the microbial surfactant product, that must be mixed together in equal parts. The manufacturer, Agro Research International, recommends a rate of 1-3 quarts/acre of each part in 20-25 gallons water/acre.
We established a cover crop stand that initially included 12 species (originally 4 legumes, 4 brassicas, and 4 kinds of grass) planted in fall 2019, but because of the very dry conditions in August-October 2019 and winter killing of the radish, we ended up with a few
plots of good cover crop biomass (>3,000 lbs/acre dry matter) consisting of mainly red, white and crimson clovers, hairy vetch, annual ryegrass, and cereal rye with the occasional turnip or kale. The covers were allowed to grow into full flowering. On May 27, soybeans were “planted green" in and the plots were sprayed with three herbicide treatments: 1) RU: the normal rate of Glyphosate, 2) WS1: the recommended rate of 1 quart/acre each part of Weed Slayer®, and 3) WS2: a rate of 2 quart/acre rate of each part of Weed Slayer® (Figure 1).
We used the Canopeo app (canopeoapp.com) to measure the green cover percentage at 2 and 7 days after spraying at 6 locations within the tire tracks and within the untracked middle area of each plot. On day 7 we also measured the green cover of the unsprayed cover crop at the edge of the field (to serve as a control). We did this in two blocks about 80 feet long and 45 ft wide. At four weeks after spraying, visual observations were made to access any possible regrowth of the cover crop.
Results. Two days after spraying, the effect of the tractor tire tracks was quite evident, with less remaining green foliage in the tracks than in the untracked middle rows of the plot (Figure 2, next page). In the untracked area, the 1 quart/acre rate of Weed Slayer® had about
25% green area remaining, which was greater than the 18% green area for the Round-Up and the 2-quart rate of Weed Slayer®. In the tire tracks, less than 10% green area remained for all three treatments.
By the 7th day after application, there was no difference among the three spray treatments in green cover in the tire tracks where the only detectable green
Figure 1. Appearance of sprayed multi-species cover crop plot 7 days after treatments were applied
foliage was that of the emerging soybean seedlings (data not shown). There was also very little difference in the untracked middle of the plot with Round-Up and Weed Slayer®2X exhibiting statistically the same percent green area (Figure 3), which was almost entirely due to the emerged soybean seedlings. The Weed Slayer® 1 quart/acre rate had about 5% green area, which was statistically greater than the Round-Up plots, and about half due to cover crop and half to soybean seedlings. The grasses were killed earlier than the legumes by both herbicides, but by day 7 all cover crop species appeared to be nearly completely killed. Most of the green cover by day 7 was due to the soybean seedlings. However, visual inspections four weeks after the spray treatments revealed some re-growth of the hairy vetch in the Weed Slayer® plots but not in the Round-Up plots. No grass regrowth was observed.
Weed Slayer® currently costs about $60/acre for the 1 x rate (purchased online in a package of 1 gallon of each part). This is expensive by conventional grain production standards, but feasible for organic grain which brings about twice the price per bushel as conventional. An affordable, effective organic-certified burn-down herbicide for grassy species (and some broadleaves) could open up important opportunities for no-till and cover cropping practices not currently practical in organic farming.
Figure 2. Percent green (living foliage) area two days after herbicide treatments were sprayed on multi-species cover crop. Measurements were made in the tractor tire tracks (right) and in the untracked middle row (left) of the plot.
Figure 3 (left). Percent green (living foliage) area seven days after herbicide treatments were sprayed on multi-species cover crop. Measurements shown are for the untracked middle rows (right) of the plot.
The annual Delaware Maryland 4R Alliance 4R Field Day will be held virtually this year online on August 25th at 9:00 AM. You can register for free here.
Nutrient Management and Certified Crop Advisor credits will be available through a separate sign-in and completing the associated quiz.
Speakers include:
Mark Williams, USDA ARS | 4R Interactions - Phosphors placement - Case studies from Indiana, Texas, and Pennsylvania
Sally Flis, The Fertilizer Institute | The Economic Case for the 4Rs - A Virginia Case Study
Unsolicited Packages of Seeds from China Maryland Department of Agriculture press release
Changes on the Use of Chlorpyrifos Adapted from Maryland State Horticulture Society Newsletter
The Maryland Department of Agriculture is aware that people across the country, including in Maryland, have received unsolicited packages of seeds from China in recent days. MDA is working closely with its partners at USDA’s Animal and Plant Health Inspection Service (APHIS) to monitor this situation.
If you live in Maryland and have received a package of seeds that you did not order, please report them immediately to the Maryland Department of Agriculture’s Plant Protection and Weed Management program at [email protected] or (410) 841-5920.
Please hold onto the seeds and packaging, including the mailing label, until MDA or USDA APHIS contacts you with further instructions. Do not plant any seeds from unknown origins.
More information on this investigation is available from USDA APHIS. Maryland Dept. of Agriculture
After several years of debate in Annapolis to ban the use of this product in Maryland, the final decisions was made to allow the phase out of this product. The manufacturer will discontinue production of this product. Instead of an outright ban, MDA has developed the phase out process which is listed below. This can be found on page 442 of the Maryland Register, Volume 47, Issue 8 dated April 10, 2020.
.02 General Requirements for Applying or Recommending Pesticides.
A.—D. (text unchanged)
E. Restrictions on Use of Insecticides that Contain Chlorpyrifos.
(1) Aerial Applications Prohibited. A person may not conduct an aerial application of any insecticide containing Chlorpyrifos in the State.
(2) Other Applications Generally Prohibited After December 31, 2020.
(a) Except as provided in §E(2)(b) and (c) of this regulation, after December 31, 2020, a person may not apply an insecticide containing Chlorpyrifos or seeds that have been treated with Chlorpyrifos in the State for any use.
(b) Fruit Trees and Snap Bean Seeds. Until June 30, 2021, a person may use an insecticide containing Chlorpyrifos or seeds that have been treated with Chlorpyrifos in the State to treat snap bean seeds and the trunks and lower limbs of fruit trees. After June
30, 2021, such applications are prohibited unless authorized by the Secretary under §E(2)(c) of this regulation.
(c) Limited Particular Use Authorization. After December 31, 2020, a person may file a written application with the Department requesting authorization to use an insecticide that contains Chlorpyrifos or seeds that have been treated with Chlorpyrifos for a particular use. If the Secretary has determined that there are no effective alternatives for the particular use noted in the application, the Secretary may authorize such use for a specified period of time, which may not extend beyond December 31, 2021.
(3) Establishment of Committee. The Secretary shall establish a committee, with members appointed by the Secretary, to determine alternatives to using Chlorpyrifos or seeds that have been treated with Chlorpyrifos, which shall dissolve on December 31, 2021.
This allows the use of this product as listed above. Please note the important dates. Until June 30, 2021, a person may use an insecticide containing Chlorpyrifos or seeds that have been treated with Chlorpyrifos in the State to treat snap bean seeds and the trunks and lower limbs of fruit trees. After June 30,2021, such applications are prohibited unless authorized by the Secretary under §E(2)(c) of this regulation. Use these products carefully .
Woodland Stewardship Programs Andrew Kling, Agent Associate, Woodland Stewardship Education Program
University of Maryland Extension
The University of Maryland Extension's Woodland Stewardship Education program offers and shares a variety of webinars, workshops, publications and educational programs for woodland owners, natural resource professionals, and interested citizens across Maryland. Please consider participating in one of these offerings. Additional events are listed on the Event Calendar at http://extension.umd.edu/woodland.
Recording of Woodland Wildlife Wednesday webinar now available
The latest webinar in our Woodland Wildlife Wednesday series, "Landowner Liability and Recreation Access in Maryland," was presented on July 29th. This webinar featured Jonathan Kays, Forestry Extension Specialist, and Paul Goeringer, Extension Legal Specialist, from the University of Maryland Extension. The webinar outlined the legal responsibilities and rights of landowners concerning recreational access and touched on the evolving case law associated with the Maryland Recreational Use Statute. The recording of the webinar is available at https://extension.umd.edu/woodland/your-woodland/webinar-recordings.
The Woods in Your Backyard online course - Fall 2020 Monday, August 31, 2020 to Tuesday, November 9, 2020 Online
Registration is now open for the Fall session of "The Woods in Your Backyard" online course. Our self-paced, non-credit course runs 10 weeks from August 31st to November 9th, 2020. The course will help landowners convert lawn to natural areas and enhance stewardship of existing natural areas. The course provides strategies to landowners of small parcels of land (1-10 acres) that improve the stewardship of their property for personal enjoyment and environmental quality. It uses a hands-on learning approach to help participants develop and implement a plan for their property. Activities include: how to map habitat areas, understanding basic ecological principles about woodland and wildlife, choosing and implementing a few habitat management projects, how to set a timetable and record your progress, online discussion groups will allow participants to interact with others taking the course. A certificate of completion is awarded when all assignments are completed.
The course costs $95.00 per person, which includes the 108-page “Woods In Your Backyard” guide, workbook, and a tree identification guide. The course is limited to 25 participants, so sign up now! For more information, go to https://extension.umd.edu/woodland/woods-your-backyard/online-course. To register through Eventbrite, go to https://wiyb-s9.eventbrite.com. For more information, contact course coordinator Andrew Kling at [email protected].
Registration closes August 31st or when class is full.
The General Forestry Course - Fall 2020 September 1 - December 15, 2020 Online or via correspondence
The University of Maryland Extension will offer the General Forestry Course for the Fall 2020 semester. Both the paper and online version will be offered. The course begins September 1 and runs until December 15, 2020. Registration is now open. To register, go to our website at http://extension.umd.edu/forestry-course.
This is a non-credit course. As there are no formal classes, you work from the comfort of your home using your own woodlot, a friend's or a public forest. You will learn how to protect your trees from insects, diseases and fire; step-by-step procedures will walk you through a forest inventory and stand analysis; and the details of the forestry business are presented, including tax nuances and the sale and harvest of forest products. Ultimately, the course exercises help you develop the framework for a stewardship plan for your forest.
The cost for this forestry course is $150. Included in the cost are copies of the supplemental readings. The paper version text and appendices are in binder form. Online users receive a flash drive of the paper version of the text and appendices. A certificate of completion is awarded when all assignments are completed.
Go to http://extension.umd.edu/forestry-course for more and a preview. For more information, contact Nancy Stewart at the University of Maryland Extension, Wye Research and Education Center, P.O. Box 169, Queenstown, MD, 21658; phone (410) 827-8056, ext. 107; or email [email protected].
Farmers and ranchers feed our state, our nation, and in fact, our world. You work long hours to provide essential resources for us all, and in these challenging times, I want you to know that USDA is here to support you and your operation through our Coronavirus Food Assistance Program, or CFAP. Whether you farm one acre or many more, grow food for local markets or big supply chains, CFAP can help. We’re accepting applications through August 28 and encouraging producers to apply now.
In Maryland, we have already approved 855 applications and disbursed $14,707,481 as of July 24, 2020. I know many of you have applied for CFAP already, but the numbers indicate that some who are eligible have not.
If you’re still un sure about CFAP and your operation, I encourage you to take five minutes today to visit farmers.gov/cfap or call (877) 508-8364 to learn about eligibility and options to apply. Whether you’ve worked with FSA for years or this will be a first, we’re here to help you every step of the way.
CFAP provides direct relief to producers who faced price declines and additional marketing costs due to COVID-19. Arange of commodities are eligible for CFAP, including Corn, Soybeans, Cattle, Milk, and Hogs. You can access the fulllist of eligible non-specialty, specialty, livestock, dairy, and wool commodities by visiting farmers.gov/cfap.
2020 Mid-Atlantic Crop Management School Going Virtual November 16-20, 2020
Reminder To Apply For Coronavirus Relief, CFAP Due August 28 Jim Eichhorst, State Executive Director in Maryland
USDA Farm Service Agency
The 2020 Mid Atlantic Crop Management School will be held virtually this year. Mark your calendars for the week of November 16-20th. Sessions will be held online daily from 8:30 am to 12:30 pm with each session offering one continuing education credit in the areas of Nutrient Management, Pest Management, Crop Management, and Soil and Water Management. Credits will also be available for various regional nutrient management and pesticide programs. Paid registrants will receive access to recordings for all sessions for viewing outside the scheduled session times. Registration will open in early September with early-bird pricing, our full list of speakers, and regional credit availability.
Want to stay up to date throughout the year and between Agronomy News postings?
Check out the Maryland Agronomy Blog. It is a searchable site that includes past and present articles. You can also subscribe to get emails when new information is posted.
http://blog.umd.edu/agronomynews/
August Insect Scouting Tips Emily Zobel, Agriculture Agent Associate
University of Maryland Extension, Dorchester County
Read and follow all label requirements for insecticides.
Soybean: Continue checking for defoliators, such as bean leaf beetle, Japanese beetle, grasshoppers, and caterpillars. Control may be needed if there is 15% defoliation on plants from bloom through pod fill. As we move into the heat of the summer, keep an eye out on your aphid population, which may increase quickly. The summer generation of soybean podworms are emerging. Fields next to maturing corn, have open canopies, are drought-stressed, or have recently had insecticide applied are at high risk for podworms. While worm feeding on flowers will not impact yields, feeding during pod development can. North Carolina State University has a great economic threshold calculator (https://soybeans.ces.ncsu.edu/wp-content/uploads/2017/08/CEW-calculator-v0.006.html) .
Alfalfa: Continue scouting for leafhopper and blister beetles.
Sorghum: Sugarcane aphids showed up in fields last year in August. Check the underside of leaves for insects. The threshold is 50 aphids per leaf on 25 – 30% of plants. They have shown some resistance to pyrethroids.
Check head for head worms and fall armyworms once heads have started to flower. Check 10 spots per field, 5 plants per spot. An easy scouting method is to use a 5-gallon bucket and shake the head into it and then count the number of medium (1/4 - 1/2 inches) and large (> 1/2 inch) dislodged caterpillars. Texas A&M has a great threshold calculator that takes the grain price and treatment into consideration (https://extensionentomology.tamu.edu/sorghum-headworm-calculator/).
Yield Impact on Heat and Drought-Stressed Soybeans Andrew Kness, Agriculture Agent
University of Maryland Extension, Harford County
According to the latest Drought Monitor report, approximately 43% of Maryland is experiencing abnormally dry to moderate drought conditions, predominantly in the central, western and southern eastern shore parts of the state. Rainfall has been sporadic in areas and July 2020 went down as the hottest month on record in Maryland since 1872. Because soybeans flower over several weeks, they can compensate for periods of drought better than crops with a short pollination period, such as corn. As a result, yield impacts from heat and drought stresses can be variable in soybean and difficult to predict.
Soybeans require between 0.25-0.33 inches of water per day, and photosynthesis peaks around 85°F. Further, soybeans are less sensitive to high nighttime temperatures than corn. However, when temperatures peak into the 90s and soil moisture becomes limited, soybeans will become stressed. In an attempt to conserve water, stomata will close, which also inhibits CO2 exchange and thus slows photosynthesis, leading to reduced growth. Soybeans will also allocate more energy to growing roots rather than vegetative tissue.
If drought conditions persist, leaves will begin to invert, exposing their silvery underside (Figure 1). The underside of the leaves reflect more light and helps to reduce water loss in the plant. The middle trifoliate of the leaf will also move upwards or flop over to cover one of the other trifoliates to help shade the leaflets (Figure 1). Nodulation and nitrogen fixation will also be reduced if high temperatures and low moisture persist, further inhibiting growth.
If heat and drought occur during the reproductive phases, soybean plants will abort flowers and pods. Even under perfect growing conditions, soybeans do not have the genetic potential to turn every flower into a seeded pod, so depending on the amount of stress, they will abort between 20-80% of their flowers. Indeterminate varieties have a longer flowering period, therefore if moisture returns, the plant can fill new pods and the effect on yield may not be significant. Furthermore, if moisture returns around R5 (beginning seed), a loss in yield from reduced pod number can be compensated by increased seed size. If drought conditions are present during pod fill, seed size may be reduced. Make sure your combine is adjusted accordingly to ensure that small-seeded beans are not going out the back of the combine.
Overall, the greatest yield reductions in soybean from drought stress occurs between R4-R6. If soybeans have a reduced pod set from stresses during flowering, good yields can still be achieved if soil moisture is adequate between R4-R6. If you intend to gauge soybean yields in the field, it is best to wait until R6. Soybean yields can be difficult to estimate from a field assessment, but this article written by Kelly Nichols provides guidance: http://blog.umd.edu/agronomynews/2018/09/07/estimating-corn-and-soybean-yields/.
Figure 1. Drought-stressed soybeans exposing the undersides of their leaves.
In Dry Weather, Watch for Silk-Clipping Insects in Corn Maria Cramer, Galen Dively, and Kelly Hamby
University of Maryland, Department of Entomology
It is not unusual to see groups of Japanese beetles feeding on corn silks, which is known as “silk clipping” Figs. 1 and 2). While Japanese beetle numbers tend to peak in July, there are multiple beetles that may clip corn silks, and with later maturity field and sweet corn silking in August, it is important to still be on the lookout But how much of a concern is silk clipping, what should you be looking for, and what should you do about it?
Silk clipping is often not as much of a concern as it initially appears. If silks are clipped after pollination, which occurs within the first 4-5 days of silk emergence1, kernel set will not be affected2. If clipping reduces the number of kernels, the kernels may develop to be larger and offset the reduction in number2. However, under drought conditions, yield loss from silk clipping is more likely2,3.
Drought slows silk emergence and pollination, which means there is a longer window where silk clipping can hurt yield. Indeed, severe drought stress can cause incomplete silk emergence and cause a mismatch between pollen shed and silks
that results in nearly blank cobs1. Drought can also make it harder for plants to compensate for poor pollination1. If leaf rolling begins in the early morning and continues until evening1, the field is stressed enough to be of concern and it is important to scout for silk clipping beetles during the first several days of silk emergence.
The culprits. Japanese beetles are the most noticeable silk clippers in Maryland because they are large, shiny, and congregate in groups (Fig. 3). They are a sporadic pest4 and their populations will vary yearly. However, their populations may be higher in corn following sod, soybean, or perennial ryegrass or clover covercrops4. Other beetles that may clip silk include the western, northern, and southern corn rootworm adults (Fig. 4)5. Western corn rootworm (WCR) has several look-alikes that do not clip silks, so make sure check the stripes; WCR will not have crisp black stripes, but instead has smudged stripes.
Scouting. Silking typically begins 3 days after tasseling5, so plan your scouting accordingly. You want to evaluate the silk stage and pollination. Silks naturally senesce about 10 days after emergence, browning and drying out. At this point, pollination can no longer occur1. To determine if green silks have been successfully pollinated, you can dissect the ear and do a shake test. Pollinated silk starts to discolor and drop away at the base of the silk where it attaches to the ear. Bob Nielson with Purdue Extension has produced a great video describing the pollination shake test: https://www.youtube.com/watch?v=K7DiwD4N0T0&feature=youtu.be
Figure 1 (left). Japanese beetles feeding on corn silks. Figure 2 (right). Silk regrowth after clipping.
M. Cramer M. Cramer
Figure 3 (left). Japanese beetle. Figure 4 (right). Adults of southern corn rootworm (left), western corn rootworm (middle), and northern corn rootworm (right).
E. Hodgson, Iowa State A. Varenhorst, South Dakota State
You should scout if pollination is incomplete. When scouting, make sure you sample both the edges and the interior (at least 40 feet into the field); while you may see alarming numbers of Japanese beetles on the edge of the field, there are usually much fewer inside the field2. Sample a minimum of 20 corn plants in 5 locations spaced evenly though the field. Count the number of beetles per ear and measure the length of the silks.
Thresholds. For Japanese beetles, three conditions need to be met to before an insecticide application will pay off: 1) there are three or more beetles per ear, 2) silks are clipped to less than ½ inch in length, 3) and pollination is less than 50% complete4 (most silks in the field are still green and/or shake test indicates about half of the silks are still attached). Conditions are similar for rootworm beetles, but the threshold is five or more beetles per ear.
Treatments. Because broad-spectrum insecticides may cause flare ups of other pests (for example, aphids or spider mites), only spray if thresholds are met. Pollen-shed is a time when there are large numbers of beneficials in the corn field doing important pest control work (Fig. 5), and foliar sprays may decrease their numbers.
For Japanese beetles, consider a perimeter spray if most of the damage is on field edges (where they tend to feed more heavily). Japanese beetles are difficult to control, but pyrethroids should provide some control (e.g., Baythroid®, Brigade®, Warrior II®, Hero®, etc.). Good adult corn rootworm control has been found for indoxacarb products (e.g., Steward®), pyrethroids (e.g.,
Warrior II®, Brigade, etc.), and neonicotinoid pyrethroid mixes (e.g., Endigo®)6,7. When using insecticides, always consult and follow the label.
If silk clipping by Japanese beetles is a consistent problem, consider cultural controls like avoiding ryegrass and clover cover crops. Because female beetles lay eggs more easily into soft ground, it is also possible to reduce egg laying in nearby fields by pausing irrigation during the peak of Japanese beetle activity4.
Additional Resources:
1. Nielson, R. L. Silk development and emergence in corn. (2020). https://www.agry.purdue.edu/ext/corn/news/timeless/silks.html
2. Steckel, S., Stewart, S. D. & Tindall, K. V. Effects of japanese beetle (Coleoptera: Scarabaeidae) and silk clipping in field corn. J. Econ. Entomol. 106, 2048–2054 (2013). https://academic.oup.com/jee/article/106/5/2048/878220
3. Dean Culy, M., Richard Edwards, C. & Ronald Cornelius, J. Effect of Silk Feeding by Western Corn Rootworm (Coleoptera: Chrysomelidae) on Yield and Quality of Inbred Corn in Seed Corn Production Fields. J. Econ. Entomol. 85, 2440–2446 (1992). https://academic.oup.com/jee/article-abstract/85/6/2440/847063?redirectedFrom=PDF
4. Shanovich, H. N., Dean, A. N., Koch, R. L. & Hodgson, E. W. Biology and Management of Japanese Beetle (Coleoptera: Scarabaeidae) in Corn and Soybean. J. Integr. Pest Manag. 10, (2019). https://academic.oup.com/jipm/article/10/1/9/5454734
5. Townsend, L. H. & Bitzer, M. J. Silk Clipping Insects on Corn. (1982). https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1053&context=anr_reports
6. DeVries, T. A. & Wright, R. J. Evaluation of Foliar Applied Insecticides for Control of Adult Corn Rootworm in Corn, 2015: Table 1. Arthropod Manag. Tests 41, tsw080 (2016). https://academic.oup.com/amt/article/41/1/tsw080/2658080
7. DeVries, T. A. & Wright, R. J. Evaluation of Foliar-Applied Insecticides for Control of Adult Corn Rootworm in Corn, 2015C: Table 1. Arthropod Manag. Tests 41, tsw096 (2016). https://academic.oup.com/amt/article/41/1/tsw096/2658095
Last month we discussed strategies for assessing pasture stands and some initial considerations when beginning to think about pasture renovations. Now that August has arrived, if you have decided to proceed with some form of pasture renovation this fall it will soon be time for planting. Regardless of the extent of your renovation, there are several steps you should follow to make sure the seeding process goes smoothly. Below is an overview of the key steps necessary for optimum forage establishment.
Step 1: Correct Soil Fertility
Poor soil fertility is one of the most common causes of poor stand establishment and also poor stand persistence over time. Acidic conditions (low soil pH) will reduce nutrient availability and impair root growth and development, and essential nutrients like phosphorus are critical for proper seedling development. Because of these effects on plant nutrient availability and utilization, ensuring adequate soil pH and fertility is essential for optimum stand establishment and to obtain persistent, high-yielding stands long term. Soil fertility testing should be done prior to renovation so that lime and fertilizer can be applied according to soil test recommendations.
Step 2: Control Weeds
Weeds compete with desirable forages for light, nutrients, moisture, and space and can shade out or outcompete new seedlings. For best results, ensure weeds are controlled prior to seeding. Remember that while herbicides can be a useful tool for weed management, they are not the only option for weed control. An integrated approach that combines various cultural, mechanical, and chemical control practices will be the most successful.
Step 3: Select Adapted Species
Not all forages will perform equally on different sites, so be sure to select forages that are well suited for your soil and site characteristics. This includes variables such as soil type, drainage, moisture holding capacity, pH, fertility, and topography. For example, species such as orchardgrass or alfalfa require a higher level of fertility and will not thrive in systems with low soil pH or poor soil fertility. Be sure to select forage species that will match your intended use (hay vs. pasture, perennial vs. annual, time of year, management system) and
livestock requirements based on species, age, and life stage.
Step 4: Inoculate Legume Seeds
If you plan to incorporate a legume as part of your forage mix, be sure the seed is properly inoculated with nitrogen-fixing bacteria. Some legume seeds come pre-inoculated, which saves time and helps to ensure inoculation. If not, be sure to select the appropriate inoculant strain depending on the legume species and inoculate the seed with fresh inoculant prior to seeding using an effective adhesive material to hold the inoculant on the seed. Inoculants are living organisms and will only work if the bacteria are alive when applied, so be sure to use proper storage and handling and check expiration dates.
Step 5: Graze and/or Clip Close
Grazing or clipping a pasture close to ground level prior to seeding will help eliminate residue and assist in suppressing competition from existing vegetation, giving new seedlings an opportunity to grow. If using livestock to accomplish this via grazing, be mindful of the potential effects this may have on animal performance, including the consumption of lower quality forage and/or the potential for increased parasite loads as animals graze below the usual minimum height recommendation.
Step 6: Prepare a Proper Seedbed
This step will vary slightly depending on the use of tilled vs. no-till seedings. If using tillage, be sure the seedbed is soft yet firm following tillage. An underworked seedbed will have too much surface residue and will be too rough for good seed placement, while an overworked seedbed will be too fluffy and fine and will dry out quickly. A good rule of thumb is that your boot tracks should be around ¼ inch deep. For no-till seedings, it is especially important to suppress the existing stand and reduce residue prior to planting. In addition to close grazing and/or clipping, the existing stand can be suppressed using a nonselective herbicide.
Step 7: Seed at the Proper Depth
Seeding too deep is one of the most common causes behind establishment failures. Be sure the seed drill is calibrated appropriately so that seed is placed at the proper depth. Take into account your soil type,
texture, and moisture conditions; in general, seed should be placed slightly shallower in a heavier soil with a higher moisture content and slightly deeper in a lighter soil with lower moisture content. For most cool-season forages, the ideal seeding depth is ¼ to ½ inch, but seed characteristics vary so be sure to determine the optimum depth and adjust accordingly prior to planting. The key is to provide good seed to soil contact without placing the seed too deep.
Step 8: Seed at the Proper Time
Cool-season forages can be seeded in either the spring or late summer. Advantages of late summer seedings generally include reduced weed competition and cooler weather conditions during establishment. The ideal time will vary depending on your location and weather conditions but in general, the optimum time for late summer seeding in Maryland occurs from mid-August through mid-September.
Step 9: Seed at the Proper Rate
Similar to seed depth, calibration is essential to
achieve a proper seeding rate. Seeding rates will vary based on forage species selection, be sure to follow recommendations when making seeding rate decisions. Pasture seeding rates are typically higher than hay seeding rates to provide a denser sod for grazing. Seeding rates can be adjusted slightly based on conditions at the time of seeding. If conditions are optimum, seed at the lower end of the recommended range. If conditions are poor, seed at the higher end of the recommended range.
Step 10: Manage New Seedings During Establishment
New seedings are especially sensitive during their establishment year. To maximize success, delay grazing on newly seeded areas until sufficient root systems have been developed to prevent livestock from uprooting newly established plants when grazed. Avoid grazing new stands during extremely wet periods, be very careful not to overgraze, and continue to scout for weeds or other potential issues that can impair establishment.
About 43% of the state is under a moderate drought or abnormally dry conditions. There are 33-60% chances of above normal temperatures in August, with greater probability as you move from Western Maryland to the Eastern Shore. The probability of above normal precipitation for August also increases as you move east in the state, ranging from 40-50% in Western Maryland, to 60-70% on the Eastern Shore.
WEATHER OUTLOOK
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Recent rains have helped replenish soil moisture to a point but only time will tell
if it helped our crops. Corn yields will certainly be reduced by the hot dry weather we experienced this year. Full season soybeans may fare a little better than the corn but we will have to wait and see. Double crop soybeans are struggling and without additional significant moisture will most likely be disappointing. A greater proportion of our corn crop will be headed to the silo and not the grain bin as dairymen stock up their winter stores. Hay stocks are also down so savvy operators will be planting oats and winter cereals for increased forage reserves.—Jeff Semler, Washington Co.
Much needed rain came with Hurricane Isaias this week, with most of the region
seeing approximately 2-4 inches of rain, according to the National Weather Service. I have not heard any reports of major flooding in the area. Corn has been more affected by the dry weather, with most lower leaves completely dried up. Corn silage harvest will begin soon. The corn earworm, fall armyworm, and western bean cutworm traps have caught very low or no moths this summer, indicating low populations this year.—Kelly Nichols, Frederick Co. Rain has been sporadic and isolated from approximately the first week of June through the third week of July. It is not common on our soil types here to see hard leaf roll in corn, but you didn’t have to look hard to find it in July. All things considered, crops do not look that bad, as timely storms right around corn pollination likely saved yields. You can find incomplete pollination in corn on lighter soils, but
overall, yield potential is still good in most fields, but likely not as big as the past few years. The hurricane brought some much-needed 2-5 inches of rain. Double crop soybeans are growing slowly and sill very short. Full season soybeans look pretty good; although many fields have reduced pod set due to the lack moisture. Recent rains should help compensate for fewer pods by making bigger beans and maybe a few more blooms. Disease pressure in both corn and soybeans has been minimal.—Andy Kness, Harford Co. With the recent 3-6” of rain, most of the region will probably have record drylands corn yields. Irrigated corn looks good, but the cloudy humid weather for the past month may have shaved some top end potential off. Gray leaf spot is sporadic with infection levels all over the board. Early corn is dented. Full season soybeans are taller than I like to see with many beans reaching 4’; well at least before the hurricane. Due to lodging, some are now 2’ tall. Double crop beans have closed over the rows. Hay yields have continued to be above average, but it has been a challenge to get it cured. Many acres of corn have been sprayed with a fungicide. Herbicide resistant weeds continue to be a problem in soybeans. And there have been a few bean fields with worms at thresh hold levels requiring treatment. Hopefully the hurricane didn’t deliver rust spores from the south.—Jim Lewis, Caroline Co. After having a dry spell, we have finally had several rain events on the Lower Shore, and crops are looking much better. Early season corn will likely have yield loss due to the dry weather during critical growth periods. Some corn is already in dent
growth stage, approaching maturity. Soybean crops are looking promising, and double-crop beans are getting a good start. Palmer amaranth is present on many farms in the area, anywhere from early vegetative growth stages to already flowering. Common ragweed is also prevalent, including young seedlings, which is surprising as ragweed is primarily a spring emerging weed. Hurricane Isaias swept through the area yesterday, which brought 1 inch of rain in Salisbury and reports of up to 3 inches in other locations. There were reports of three tornados that touched down on the Lower Shore. As of yet we have not gotten reports of major crop damage from high winds.—Sarah Hirsh, Somerset Co.
With regular rains over the
past month, most corn and soybean crops have been in good to excellent
condition. Most grain sorghum fields are headed out and sugarcane aphids are starting to show up in low numbers, though headworm pressure seems to remain low at the time. The area saw between 2 to 10+ inches of rain from the tropical storm that moved through on Aug 4, with much of the heavier rain to the south and east. High winds saw some blowdown of soybean crops, which should recover. More damage is expected to be seen in vegetable crops, especially where heavy rains and standing water will likely lead to disease problems through the rest of the season.—Alan Leslie, Charles Co.
CENTRAL MARYLAND
WESTERN MARYLAND
NORTHERN MARYLAND
UPPER & MID SHORE
LOWER SHORE
SOUTHERN MARYLAND
CROP REPORTS Regional
VOLUME 11, ISSUE 5 AGRONOMY NEWS: AUGUST 2020
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Agronomy News is published by the University of Maryland Extension, Agriculture & Natural Resources Agronomy Impact Team.
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