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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NewsDon't Guesstimate: Free Testing for Soybean Cyst Nematode (SCN) is Available
Date Posted 4/21/2026Spring is here, and farming operations are ramping up. If you are a soybean grower, this is also an appropriate time to take soil samples and have them tested for soybean cyst nematode. Testing is free for all soybean growers in Pennsylvania. -
News2026 Pennsylvania Slug Monitoring Project
Date Posted 4/21/2026Grey garden slug numbers decreased this week. Eggs and juveniles found in some counties. -
NewsExpired Pesticide License?
Date Posted 4/14/2026Has your pesticide license lapsed or expired and what is the difference? The following are simplified instructions for reinstating your lapsed or expired pesticide license. -
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. -
ArticlesBlack Cutworm Management in Organic Field Corn
Ecological pest management and cultural strategies are the best method for protecting crops against black cutworm damage on organic farms. -
NewsWatch for Alfalfa Weevil Larvae; Some may be Resistant to Pyrethroids
Date Posted 4/7/2026Alfalfa weevil larvae are becoming active, particularly in southern counties and south-facing fields. Scout your fields to detect their damage but recognize that some fields in eastern counties have resistant populations -
NewsWinter Grain Mites are Being Found in Triticale and Rye Fields
Date Posted 4/7/2026Populations of this pest species, which are becoming more common in Pennsylvania, can grow in fields planted annually with small grains. -
ArticlesUsing Bulletins Live! Two to Meet Endangered Species Act (ESA) Requirements
Pesticide applicators must check the Bulletins Live! Two website to know additional safety guidelines which must be followed before a pesticide application in an area where habitat for endangered/threatened species is present. -
ArticlesSoybean Aphid
Larger aphid populations can heavily stress plants, reducing yields by up to 40%. -
ArticlesManaging Belowground Insect Pests in Field Corn
Belowground pests can be challenging in corn production (grain or silage), particularly when it is grown in the same fields year after year. -
ArticlesBlack Cutworm
In Pennsylvania field crops, black cutworm is most often a pest of corn, but can also cause trouble in wheat and tobacco. -
VideosScouting for Slugs in Field Crops
Length 6:02A practical scouting method for slugs and how to identify slug damage in field crops. -
NewsUpdated Agronomic Fungicide Efficacy Tables
Date Posted 3/17/2026Arm yourself with knowledge to keep this season's crops healthy. -
ArticlesPlant Parasitic Nematodes Explained
Have you noticed a decline in yield without a clear explanation? It could be due to plant parasitic nematodes. -
NewsSoil Fumigation Credit Opportunity
Date Posted 3/9/2026A workshop covering soil fumigation principles and practices offering to PDA category 21 credits is being offered by Penn State Extension. -
ArticlesParaquat Safety
Use of paraquat dibromide, or paraquat, has been increasing in popularity among agricultural producers. However, this product has safety and handling risks associated with its use. -
ArticlesHelpful Resources for Wheat and Barley Scab Prevention
Getting useful, accurate information about crop disease risk is likely one of your top priorities. Make sure you know the tools to help you fight Fusarium Head Blight throughout the year. -
NewsHighly Pathogenic Avian Influenza: "What, Me Worry?"
Date Posted 1/9/2026Everyone plays a role in preventing the spread of HPAI. -
Guides and PublicationsStarting at $8.00
Mid-Atlantic Field Crop Weed Management Guide
Get up-to-date strategies and detailed herbicide tables for managing weeds in corn, sorghum, soybeans, small grains, and forages across the Mid-Atlantic region. -
NewsCHEMSWEEP Program Opens for 2026 Collections
Date Posted 12/2/2025Sign Up by March 31. CHEMSWEEP collects and disposes of unwanted or unusable pesticides. -
ArticlesNo-till Farming and Healthy Soils Work Hand in Hand
No-till and cover crops are essential for healthy soils, but also require some additional management and attention to detail. -
ArticlesHarvest Your Soybean Fields and Get Them Tested for Soybean Cyst Nematode (SCN)
When soybean harvest is on the way, make sure you add testing for soybean cyst nematode (SCN) to your to-do fall list. -
NewsHerbicide Recommendations for Winter Small Grains
Date Posted 10/7/2025Small grain establishment and growth can be hindered by weeds, but here are some herbicide options to consider for problem weed species. -
ArticlesAvoiding Mycotoxins in Grain Corn and Silage
Toxins caused by fungi are a real concern in grain corn and silage. Is there anything we can do about it? -
ArticlesGround and Tiger Beetles (Coleoptera: Carabidae)
Ground and tiger beetles are important biological control agents in agroecosystems. They consume many soil dwelling insect pests.


