Pests and Diseases
Pests and diseases can decimate agronomic crops and result in huge financial losses. Make use of Penn State Extension’s substantial library of resources including recommendations for managing weeds, insects, and disease pests in a variety of agronomic crops. Find tips on dealing with bacteria, molds, fungal diseases, and rot.
Agronomic Crops Diseases and Integrated Pest Management
There are several ways to deal with pests. If you want to use pesticides on your agronomic crops you may need a license. To maintain a valid applicator’s license in Pennsylvania, private pesticide applicators must fulfil a continuing education requirement. Penn State Extension provides a number of workshops for anyone looking to become certified or recertified. They include Agronomic Pesticide Update workshops, an online course covering What's New in Agronomic Pest Control, and an Agronomic Pesticide Update Webinar. The Penn State Agronomy Guide also covers pest management.
Many different pests can affect agronomic crops; for example, slugs are a challenging pest for no-till farmers. New herbicide products are regularly released making pest management even more demanding. It’s not something crop producers have to face on their own. Certified crop advisers can help producers with pest management as well as studying soil and water, crop, and nutrient management.
Common Corn Pests and Diseases
A number of different pests and diseases can affect corn crops at various growth stages. Mild temperatures and increased humidity, for example, can lead to corn leaf blight and gray leaf spot. Corn ear rot and mycotoxins can also be a problem when humidity is high. Knowing what corn diseases to look for means you can make the right decisions on what to spray, and indeed whether to spray at all.
As well as combating diseases, corn producers also have a number of pests to contend with. An increase in reduced-tillage culture and planting corn into sod and small grain cover crops has led to an increase in armyworm damage.
Several species of billbugs feed on corn plants causing damage in May. The adults chew small holes in the stems which can severely retard or even kill small plants.
Pests that cause damage below ground can be challenging to control, particularly in corn production. Crop rotation is one way to reduce numbers. The seedcorn maggot is one example.
Common Soybean Pests and Diseases
Soybean production has steadily been increasing in Pennsylvania. Being able to assess soybean fields for insect damage and learning how to recognize soybean pests are important factors for successful and profitable agronomic crop production. The soybean aphid, for example, is an exotic pest of soybean that can heavily stress plants, leading to a reduction in yields of up to 40%.
Soybean diseases such as stem canker, brown stem rot, and sudden death syndrome can also wreak havoc on soybean crops.
Wheat and Small Grains Common Pests and Diseases
For wheat and small grains producers, there is the added complication of pests being present in stored grain. The Angoumois Grain Moth, for example, can make grain smell unpleasant, making it less attractive for consumption. Foreign grain beetles are a fungus-feeding insect commonly found in grain stored on farms in Pennsylvania. The sawtoothed and merchant grain beetles are two more pests that can contaminate stored grains.
Effective control of stored grain pests requires an IPM approach that combines sanitation, identification, monitoring, and preventive practices.
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NewsUseful Resource for Navigating Corn Insect-resistance Traits
Date Posted 3/31/2025The Handy Bt Trait Table has been updated for 2025 and can help sort out the transgenic, insect-resistance traits available. -
NewsHow to Become a Private Certified Pesticide Applicator
Date Posted 3/24/2025New applicator? First time using restricted-use pesticides? Fumigants? Retesting after a lapsed license? These are the simplified steps to obtain a private pesticide license. -
NewsUpdated 2025 Fungicide Efficacy Tables
Date Posted 3/18/2025Arm yourself with knowledge to keep this season's crops healthy. -
NewsSpring Weedy Grass Control in Grass Hay and Pasture
Date Posted 3/18/2025Considerations for weedy grass and broadleaf control options in grass forages during early spring. -
NewsPractice Biosecurity to Reduce the Risk of Highly Pathogenic Avian Influenza
Date Posted 2/18/2025With the recent HPAI outbreak, practicing vigorous biosecurity is a must, regardless of flock size. -
ArticlesDiagnosing a Plant Problem 101
Use this step-by-step method to narrow down the possibilities of your plant problem, but don't forget to ask the experts if you need to. -
NewsCorn Mycotoxins: What's in Your Bin?
Date Posted 1/21/2025Send us a sample to help us determine the fungi responsible for mycotoxin contamination in Pennsylvania corn. -
Guides and PublicationsStarting at $15.00
The Penn State Agronomy Guide
An updated, 2025 edition of this guide that provides information on crop and soil management, as well as recommendations for managing weed, insect, and disease pests in various crops. -
NewsEmbrace the Cold: It is Likely to Restrict Some Pest Species Populations
Date Posted 1/7/2025Cold temperatures can knock back some pest species, including slugs, but outcomes can be hard to predict. -
Guides and PublicationsStarting at $5.00
2024 Agronomy Research Report
A research report highlighting the results of new, continuing, and completed agronomic projects conducted by Penn State investigators and their collaborators in 2024. -
NewsCertified Crop Adviser Credits Available Online
Date Posted 12/10/2024Do you need continuing education credits before the end of the year? We have you covered. -
ArticlesWhy Is My Wheat Yellow?
Early-season Symptoms in Small Grains and Cereal Forages? Let's talk about some possibilities. -
ArticlesFall Armyworm as a Pest of Field Corn
Fall armyworm larvae can be difficult to control due to the timing of infestation in Pennsylvania. Insecticide control options should be attempted only in extreme situations. -
ArticlesThe Value of Bats to Crop Production and Revenue
Because they eat insects, bats can provide great value to agriculture by controlling insect pests. Recent research has shown that widespread declines in bat populations have resulted in unexpected costs for farms and human health. -
NewsSoybean Seed Diseases: Bad Weather's Bitter Harvest
Date Posted 10/15/2024In some areas of Pennsylvania, farmers are reporting higher than-normal incidence of soybean seed diseases. What are the different symptoms and signs? Where did they come from? -
ArticlesSolving the Case of Crop Disorders: The Role of Patterns in Diagnosis
This article covers a piece of the field diagnostic puzzle: patterns in agronomic crop problems that help diagnose abiotic disorders and contrast them with biotic pests and pathogens. -
ArticlesFrom Aflatoxin to Zearalenone: Mycotoxins You Should Know – Deoxynivalenol (DON)
The presence of deoxynivalenol (DON, vomitoxin) in grain crops causes great economic losses. Why is it a concern? Where does it come from? -
NewsEvaluating Late Season Diseases in Small Grains
Date Posted 6/11/2024Assessing disease incidence and severity is important to determine the impact of small grains diseases on yield. -
NewsIn Northern Pennsylvania, it is Time to Scout for Black Cutworm Damage in Corn
Date Posted 6/4/2024In Potter and other counties in northern Pennsylvania, now is the time to begin scouting for black cutworm damage in corn fields. -
NewsScout for Cereal Leaf Beetle Larvae, But Don't Spray Blindly
Date Posted 5/28/2024Cereal leaf beetle larvae are active. Scout your fields to assess their population size; spraying blindly is unlikely to be profitable. -
ArticlesEarly Season Herbicide Injury to Corn
Sometimes, early-season crop injury can occur from herbicides. This article overviews specific symptoms and conditions typically associated with herbicide injury in corn and soybeans. -
Tools and AppsThe Open Crop Manager Platform for Crop Production and Scouting
The Open Crop Manager (OCM) platform provides a system for crop production information, scouting, and database management to help increase knowledge, crop sustainability, and profitability. -
NewsSpring Oat Herbicide Options
Date Posted 4/30/2024Weeds can be a problem in spring oat fields. This article provides some herbicide options to consider. -
VideosPoison Hemlock Identification
Length 2:08Learn how to identify poison hemlock, a toxic weed, growing in Pennsylvania. -
VideosPreventing Stored Grain Pests
Length 4:10Avoid costly docking at the mill and grain fumigation expenses by taking the steps necessary to prevent a stored grain pest infestation.



