Penn State Extension Field and Forage Crops

What’s in the field? Soybean IPM 🧐

In central PA, we’ve been finding silver-spotted skipper caterpillars in soybeans. These caterpillars, which will turn into butterflies, have a greenish-yellow body and a dark reddish-brown head capsule with two orange eyespots.

They feed along leaf edges of soybeans, but rarely cause economic harm. Silver-spotted skipper caterpillars create leaf shelters. They roll or fold over leaves and use silk to stick the leaves together. This creates a shelter that protects them from predators.

If you see rolled or folded soybean leaves while scouting, pull them open to see if there are caterpillars. For management, follow soybean defoliation thresholds. Early in the season, before flowering, soybeans can tolerate around 25% total defoliation before insecticides are needed.

🌱🚜 Join us for Farming for Success 2026!

Walk research plots, hear from specialists, connect with sponsors, and earn valuable recertification credits.

📅 June 25, 2026
📍 Penn State Southeast Agricultural Research & Extension Center, Manheim, PA

Topics include:
✔️ Making a farm emergency plan
✔️ Seed testing, seedling diseases, and seed treatments
✔️ Hail damage and corn planter mishap demos
✔️ Burcucumber management
✔️ Opportunities to network with fellow producers and ag professionals

AND MORE!

Whether you're a farmer, crop consultant, ag retailer, or industry partner, there's something for everyone!

👉 Register today:

Farming for Success Agronomic field day featuring crop research, best practices, and expert insights, with opportunities to explore field plots and connect with industry professionals and sponsors.

🌱 We are entering a critical period of growth for corn and soybeans in parts of Pennsylvania--did your soil capture enough from the last rain event to get you through til the next one?

With unpredictable rainfall patterns, healthy soil is one of your farm's best risk-management tools.

Practices like cover crops, using manure, reduced tillage, and diverse crop rotations help build soil organic matter. This improves the soil's ability to capture and store water for later use. Healthy soils can also improve infiltration during heavy rain events, reducing runoff and keeping more moisture available for crops when conditions turn dry.

💧 More water stored in the soil profile
🌾 Better crop resilience during drought
🚜 Reduced erosion and runoff losses

Soil health isn't just about what's happening below ground—it's about helping crops withstand whatever the growing season throws at them.

What soil health practices have you found most effective for managing weather extremes on your farm?

🌱 Residual Herbicide Activation: Are Conditions Adequate? 🌧️
Many corn and soybean fields have been planted in the past week, and planting continues in earnest given the current weather. While a chance of some moisture is forecast for this weekend, long range guidance is showing another dry stretch of weather next week.

Effective performance of soil-applied residual herbicides in corn and soybean systems depends on timely rainfall to move active ingredients into the w**d seed germination zone.
Key activation guidelines:
🔹 Moisture requirement:

~0.5 inch rainfall is generally considered the minimum for activation
0.75–1.0 inch provides more consistent and uniform control

🔹 Herbicide properties:

Higher solubility products may activate with 0.25–0.33 inch of precipitation
Lower solubility materials require greater moisture for adequate incorporation

🔹 Timing:

Rainfall should ideally occur within 7–10 days after application
Activation prior to w**d emergence is critical to maximize efficacy

🔹 Field conditions influencing activation:

Dry soil at application can delay herbicide movement
High residue systems may intercept rainfall and reduce soil contact
Clay-rich soils may require more total moisture for uniform distribution

👀 Management implications:
Where adequate rainfall has not occurred within 10–14 days, and w**d emergence is observed, growers should begin evaluating the need for a timely post-emergence application to maintain control and protect yield potential.
📌 Take-home message:
Residual herbicides are only effective once they are properly activated. Until sufficient precipitation occurs, performance may be limited or inconsistent.
The attached table from the Penn State Agronomy Guide provides more information on specific herbicides and their rainfall requirements. Check out this Penn State Extension article for additional information as well:
https://extension.psu.edu/herbicides-dont-let-the-planter-outpace-the-sprayer

Always consult the product label for specific use requirements. Contact your local Penn State Extension Field & Forage Crops Educator with questions.

It's time for a pasture walk!🎉

These pasture walks are designed to help you improve pasture quality for grazing animals. The livestock team will attend two pasture walks in June!

📍Butler | Pasture Walk with Extension: Sheep Farm | June 11th | https://extension.psu.edu/pasture-walk-with-extension-sheep-farm

📍Bedford | Pasture Walks with Extension: Beef and Sheep | June 22nd | https://extension.psu.edu/pasture-walks-with-extension-beef-and-sheep