Grower Resources
Practical Tools We Reference When Making Agronomic Decisions
Field Insights is built around what our team sees in fields across North Dakota, South Dakota and Minnesota. The resources below are tools we regularly reference to help diagnose issues, validate observations and guide conversations with growers.
We’ve created this page as a central hub. As new questions come up throughout the season, this page allows you to dig deeper into specific topics using trusted, research-backed sources.
If you have questions about how any of these apply to your operation, that’s where our agronomy team comes in. These tools support the conversation; They don’t replace it.
Planting, Residue & Stand Establishment
Resources focused on planting method, seed placement, residue management and early stand issues.
Purdue Extension – Corn & Soybean Residue Management
Estimate residue cover and understand how residue levels impact planting performance.
https://www.extension.purdue.edu/extmedia/ay/ay-269-w.pdf
University of Missouri – Drilled Soybeans Guide
Guidance on drilled soybeans, seed depth, seed-to-soil contact and seedbed quality.
https://extension.missouri.edu/publications/g4415
NRCS – Residue Management Conservation Guide
Overview of residue management practices in no-till systems.
https://mssoy.org/sites/default/files/documents/nrcs-wisc-residue.pdf
NDSU Extension – Soybean Growth & Development
Visual reference for VE–V2 stages where early injury and residue-related bruising occur.
https://www.ndsu.edu/agriculture/sites/default/files/2022-07/soybean_growth_&_development.pdf
Corn Rootworm: Identification, Trapping & IPM
Used alongside trapping data, field history and hybrid placement discussions.
NDSU Extension – Corn Rootworm IPM in North Dakota
Regional IPM guidance, including extended diapause considerations.
https://www.ndsu.edu/agriculture/extension/publications/integrated-pest-management-corn-rootworms-north-dakota
Iowa State University – Corn Rootworm Trapping Network
Sticky trap setup, weekly count protocols and beetle identification.
https://cornrootworm.extension.iastate.edu
South Dakota State University – Corn Rootworm Adult Updates
Beetle emergence timing and scouting updates.
https://extension.sdstate.edu/corn-rootworm-adults-are-emerging-south-dakota
Wind Damage, Mechanical Injury & Residue Movement
Helpful when symptoms don’t fit a classic disease pattern.
University of Minnesota – Plant Disease Clinic
Submit soybean stems, roots or tissue samples for diagnosis.
https://pdc.umn.edu
Iowa State Extension – Crop Damage Diagnostic Resources
Tools to diagnose wind, residue, hail and mechanical injury.
https://crops.extension.iastate.edu/cropdamage
Soybean Aphids: Thresholds, IPM & Economics
Referenced when making spray decisions, especially in low-price years.
University of Minnesota – Scouting Soybean Aphids
Step-by-step scouting process and the 250 aphids/plant threshold explanation.
https://extension.umn.edu/soybean-pest-management/scouting-soybean-aphid
South Dakota State University – Why the 250 Threshold Still Works
Economic validation of the aphid threshold.
https://extension.sdstate.edu/why-250-threshold-still-appropriate-soybean-aphids
Wisconsin Extension – Beneficial Insects in Soybeans
Identification guide for natural aphid predators.
https://cropsandsoils.extension.wisc.edu/articles/managing-soybean-aphids-in-wisconsin-soybean-fields
Corn Diseases, Fungicides & Decision Tools
Supports tar spot, rust, GLS, NCLB and fungicide timing decisions.
Crop Protection Network – Tar Spot of Corn Web Book
https://cropprotectionnetwork.org/web-books/tar-spot-of-corn
CPN – Tar Spot Management Section
https://cropprotectionnetwork.org/web-books/tar-spot-of-corn?section=management-of-tar-spot
IPCM – Tarspotter App
https://ipcm.wisc.edu/apps/tarspotter/
IPM PIPE – Tar Spot & Southern Rust County Maps
https://corn.ipmpipe.org/
Fungicide Tools
Iowa State Extension – Fungicide Classification Chart
https://store.extension.iastate.edu/product/Fungicide-Classification
Crop Protection Network – Corn Foliar Fungicide Efficacy Table (2025)
https://cropprotectionnetwork.s3.amazonaws.com/corn-foliar-efficacy-2025.pdf
Crop Protection Network – Fungicide Efficacy Tool
https://cropprotectionnetwork.org/fungicide-efficacy-tool
Crop Protection Network – Corn Fungicide ROI Calculator
https://cropprotectionnetwork.org/fungicide-roi-calculator
Soybean Diseases & Seedling Pathogens
Background information that supports early-season disease diagnosis and seed treatment decisions.
Peterson Farms Seed – Soybean Seedling Disease Series
- Fusarium (Dry Rot):
https://www.peterson.ag/soybean-seedling-disease-series-part-4-fusarium-the-dry-rot/
- Phytophthora (The Silent Killer):
https://www.peterson.ag/soybean-seedling-disease-series-part-1-phytophthora-the-silent-killer/
- Rhizoctonia (The Root Killer):
https://www.peterson.ag/soybean-seedling-disease-series-part-2-rhizoctonia-the-root-killer/
- Pythium (The Seedling Killer):
https://www.peterson.ag/soybean-seedling-disease-series-part-3-pythium-the-seedling-killer/
Weed Resistance & Integrated Weed Management
Used when discussing waterhemp, kochia and resistance management.
GROW – Getting Rid of Weeds (Integrated Weed Management)
https://growiwm.org/
Herbicide-Resistant Kochia in ND Sunflower Fields – Brian Jenks
https://www.sunflowernsa.com/magazine/articles/default.aspx?ArticleID=4148
ND Soybean Council – ND Herbicide Resistant Weed Survey
https://ndsoybean.org/north-dakota-herbicide-resistant-weed-survey/
Soybean Cyst Nematode (SCN)
Testing, management strategies, and economic tools.
The SCN Coalition
https://www.thescncoalition.com/
Iron Deficiency Chlorosis (IDC)
Placement and management references.
University of Minnesota – Managing IDC in Soybeans
https://extension.umn.edu/crop-specific-needs/managing-iron-deficiency-chlorosis-soybean
Peterson Farms Seed – Updated IDC Scores
https://cdn.flowcode.com/prodassets/2024_IDC_Adjustments.pdf
Diagnostic Labs (ND, MN, SD)
When field symptoms need confirmation.
NDSU Plant Diagnostic Lab
https://www.ndsu.edu/agriculture/extension/plant-diagnostic-lab
University of Minnesota – Plant Disease Clinic
https://pdc.umn.edu
South Dakota State University – Plant Diagnostics Lab
https://extension.sdstate.edu/plant-diagnostics-lab
Have Questions?
These resources help explain what is happening. Our agronomy team helps answer what to do next.
If something in your field doesn’t look right, or if you want to talk through risk, placement or management, reach out to your local Peterson team member. That’s exactly what we’re here for.
