Crop Scouting Basics - Women in Agriculture | Nebraska · 2020-02-19 · •Round Up Ready 2 Xtend-...

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Jennifer Rees, Sarah Sivits, and Megan TaylorNebraska Extension Educators

jenny.rees@unl.edu, sarah.sivits@unl.edu, mtaylor42@unl.edu

Crop Scouting BasicsUniversity of Nebraska-Lincoln Extension

Sarah Sivits , Megan Taylor, Jenny Rees

1. What pattern would you use to scout your field?

• A = around the perimeter

• B = X pattern

• C = 55 mph drive by

• D = Z pattern

2. Soybean Gall Midge Larvae are Most Likely Found?

• A = In the roots

• B =In the middle of the plant

• C = At the top of the plant

• D = At the bottom of the plant near ground level

3. Palmer Amaranth has a _______ Petiole Compared to Waterhemp?

• A = Same Length

• B = Longer Length

• C= Shorter Length

4. What is the economic threshold of soybean aphids?

• A = 100

• B = 250

• C = 50

• D = 328

5. What is this soybean foliar symptom?

• A = PPO damage

• B = frog eye leaf spot

• C = Soybean mosaic virus

• D = dicamba drift

Types of Pests

Weeds Diseases Insects

Photos courtesy Megan Taylor

Pest Development and Biology

• Insects—complete or gradual metamorphosis

Thistle Caterpillar

Complete Metamorphosis

Stink Bugs

Soybean Gall Midge

Damage in Field

The Big Five

• Western Bean Cutworm (WBC)

• Soybean Gall Midge

• European Corn Borer

• Aphids

• Japanese Beetles

Pest Development and Biology

Environment Pathogen

Disease

• Diseases—understanding the disease triangle

Sudden Death Syndrome

Frogeye Leaf Spot

Gray Leaf Spot

2019 - QoI Fungicide Resistance Confirmed in Cercospora sojinacausing Frogeye Leaf Spot in 10 Nebraska Counties

Neves, D., Jackson-Ziems, T., and Bradley, C. 2019.

#IRPests

FUNGICIDE

RESISTANCE

IS HERE!

Ribbet-ing

Pest Development and Biology• Weeds - annuals, biennials, perennials

Palmer Amaranth• Most problematic weed (32 states)

• High water use efficiency

• High photosynthesis rate (96°F-120°F)

Female

Integrated Pest Management

• Broad based approach

• Integration of practices for economic control of pests

Type of Pest

Management Thresholds

Resistance Management

Type of Control Method

IPM Steps

1. Identify pest

2. Evaluate pest damage

3. Determine need for controls

4. Consider multiple control options

5. Select best combination of control options

6. Monitor your selection

Control

Resistance/

TolerancePhysical/

Mechanical

Cultural

Biological

Chemical

Regulatory

Management

Biological Control

Photo Cred: W. Archibald, J. Peterson

Photos courtesy Julie Peterson

Management Thresholds

• Aesthetic

• Action

• Economic

Economic Threshold

Figure credit: Ed Zaborski, University of Illinois.

Application of economic thresholds

• Soybean Aphids-250 aphids per plant reaches ET

• What about Frogeye and White Mold?• Risk Management Thresholds

• Iwilltakeaction.com

Risk Thresholds

www.iwilltakeaction.com

Application of economic thresholds

Economic thresholds for bean leaf beetles

in soybeans at the V1 stage.

Management costs

Crop Value $6 $8 $10 $12

Threshold number of beetles/plant

$7 3 4 5 6

$8 3 3 4 5

$9 2 3 4 4

$10 2 3 3 4

Source: Tom Hunt University of Nebraska-Lincoln

Pesticide Resistance Development• Application of a pesticide creates selection pressure,

leading to survival of individuals that possess genes conferring resistance

• Percentage of population with resistance increases with selection over time

Frogeye Leaf Spot

Questions for Trivapro Fungicide Label (selected pages)• 4. What potential hazards to the environment exist when using this pesticide?

• 6. If a restricted-entry interval (REI) is present, what is the REI?

• 8. List the different methods of application that can be used?

• 9. What (soybean) pest(s) does this product aim to controlled? List at least three pests controlled

• Extra: What does the label state about resistance management

• DEQ and NDA want a level of competency for reading and understanding what is on a pesticide label

Cost of Resistance • Obsolete technology• Increased pest pressure• Increased cost of production for growers

Soybean Trait Selection

• Soybean Traits • Round Up Ready 2 Xtend- Glyphosate and Dicamba

• Enlist E3- 2-4D choline, Glyphosate, and Liberty

• Liberty Link GT27- Glyphosate, Liberty, and HPPD

• Roundup Ready 2 Yield- Glyphosate• Liberty Link- Glufosinate

• Conventional-no herbicide resistance

• WG 127-140

Resistance Management • Accurate identification of pest • Multiple modes of action• Timing • Crop rotation

• https://iwilltakeaction.com/

Weed Guide Picture

Scouting Activity

Field Results—Soybeans

Diseases

• Frogeye Leaf Spot

• Sclerotinia Stem Rot (White Mold)

• Sudden Death Syndrome

Insects

• Aphids

• Dectes Stem Borer

• Thistle Caterpillar

Field Results—Soybeans

Deficiencies/Other• Iron Deficiency

• Soybean Cyst Nematodes

Herbicide Injury• PPO Inhibitors

• ALS Inhibitors

• Photosystem II Inhibitors

Field Results—Corn

Diseases• Gray Leaf Spot

• Northern Corn Leaf Blight

• Common Rust

Insects• Spider Mites

• European Corn Borer

• Western Bean Cutworm

Field Diseases—Corn

Deficiencies/Other

• Nitrogen Deficiency

• Potassium Deficiency

• Wind/Hail Damage

Speed scouting apps available

•First generation European corn borer•Second generation European corn borer•Western bean cutworm•Soybean aphid

•https://extension.unl.edu/extension-apps/

Speed scouting apps

This spreadsheet is designed to be used in the field on mobile devices, allowing the user to make management decisions immediately after scouting. Speed scouting is one method for determining whether soybean aphids have reached the treatment threshold of 250 aphids per plant. It relies on the

number of "infested" plants rather than estimating the number of aphids on each plant. Plants are considered "infested" if there are 40 or more aphids on the plant. After inputting your field information, the spreadsheet will suggest the next step: "Resample in 7-10 days," "Sample 5 more plants," or "Treat,

confirm in 3-4 days."

Wayne J. Ohnesorg, Extension Educator; Thomas E. Hunt, Extension Entomologist;

and Robert J. Wright, Extension Entomologist

EC 1582

Soybean Aphid Speed Scouting Spreadsheet