Pests and Diseases
Pests and diseases can have a far-reaching effect on vegetable crops. For the home gardener, they can be an inconvenience, but for commercial vegetable producers, they can be catastrophic.
Make use of Penn State Extension’s comprehensive library of resources including recommendations for managing pests and diseases for vegetables such as tomatoes, potatoes, onions, asparagus, squash, peppers, and many more. Find tips on dealing with worms, maggots, leaf miners, beetles, and mites, and scouting for pests. Penn State Extension also regularly publishes PestWatch Reports and Pennsylvania Vegetable Disease Updates in this section.
Common Vegetable Diseases
Vegetable diseases take their energy from the plants on which they thrive. Much the same as pests, diseases can be responsible for a great deal of damage. Wet weather, poor drainage, or inadequate airflow often encourages them. A variety of symptoms, including moldy coatings, wilting, blotches, scabs, rusts, and rot typically characterize plant diseases.
There are several common vegetable diseases that growers should be aware of. Timber rot, also known as Sclerotinia or white mold, can be a problem if air circulation and moisture retention are poor. Leaf mold can cause problems when you grow tomatoes in high tunnels. Early blight, caused by the fungus Alternaria solani, is a common problem for potato growers, particularly in warm weather regions that alternate between dry and wet.
There are distinct symptoms you can look for if you want to identify vegetable diseases. Penn State Extension’s Identifying Potato Diseases in Pennsylvania publication contains color photos to help determine what diseases are affecting your potato crops.
Preventative plant disease management tactics are the best approach to manage diseases. Basic principles include avoidance, exclusion, use of resistant varieties, accurate pathogen diagnosis, and pathogen reduction. Plant analysis plays a crucial role in determining what is wrong with your crops.
Scouting should be used to monitor your fields for the presence of diseases and pests or any potential issues that could hamper the growth of your vegetable crop. If your cucurbit crops are wilting, it could be cucurbit yellow vine decline, Fusarium, or bacterial wilt that is causing the problem.
Vegetable Garden Pests
Various insects and pests can damage vegetables in the garden and they can attack at all growth stages. The spotted lanternfly is an invasive insect that has been spreading throughout Pennsylvania for several years now.
Let’s not forget there are also lots of beneficial insects you can find in and around vegetable crops. Common natural enemies in high tunnels include green lacewings, lady beetles, and parasitoid wasps, all of which enjoy feasting on aphids, scales, and mites.
If you find white meandering tunnels in your chard, beet, or spinach leaves, your vegetables may be falling victim to leaf miners. The legless yellow to white larvae cause damage when they burrow between the layers of the leaves as they feed. Onion, seed corn, and cabbage maggots attack seeds and small seedlings.
Tomato hornworms can be a problem for tomato plants from July through early September in Pennsylvania. A single lime green, small shiny egg on the top or bottom surface of leaves of not only tomatoes but pepper and other solanaceous crops indicates their presence. Broad mites are another pest that can cause severe damage to peppers and tomatoes. You can protect your crops with an effective miticide.
Vegetable Crops and Integrated Pest Management
Integrated pest management (IPM) is a way you can manage insects, diseases, weeds, animals, and other pests that cause damage. It involves a combination of biological, cultural, mechanical, and chemical practices. You can apply the principles of IPM to both commercial and home vegetable growing. The key to applying integrated pest management is scouting for pests and diseases in vegetable crops.
Biological practices include releasing insects and mites along with bio-pesticides composed of specialized fungi and bacteria. Insect pheromone traps can also be used to help control insect pests such as black cutworm. Heat treatment of the soil is another practice that has a place in an integrated pest management system.
Vegetable Pesticide Application
There are several effective ways to deal with pests. If you want to use pesticides on your vegetable crops, you may need a license. You must fulfill a continuing education requirement if you want to maintain a valid private pesticide applicator license in Pennsylvania.
Penn State Extension provides a number of workshops for anyone who is looking to become certified or recertified. The courses available include the Private Pesticide Applicator Short Course in Spanish and English. A pesticide spray record-keeping spreadsheet is also available.
If you want to take the guesswork out of spraying there are smartphone and tablet apps you can use to help in sprayer calibration, nozzle selection, tank mixing, and product selection.
- News
2024 Disease Alert: Late Blight Outbreak in High-Tunnel Tomatoes in NY
Date Posted 4/18/2024A late blight outbreak was observed on high-tunnel tomatoes in southern Onondaga County (NY) the week of April 8. - Articles
Rotten to the Core: The Center Rot Disease of Onion
Center rot causes significant economic loss to the onion bulb industry in the United States. - Articles
Growing Cucumbers in High Tunnels
Cucumbers are a high-value crop that is grown in a variety of systems including high tunnels. Here, we are presenting the basics of high tunnel production for beginning farmers or those looking for a refresher. - Articles
Crecimiento de Pepinos en Túneles Altos
AquÃ, estamos presentando los conceptos básicos de la producción de túneles altos para los agricultores y agricultoras principiantes o aquellos que buscan un refresco. - Articles
Sap Beetle Management in Sweet Corn
Although there are many species of sap beetles only several become pests in agricultural crops. - News
Allium Leafminer on Track to Emerge Early April, 2024
Date Posted 3/13/2024Allium leafminer is an invasive fly from Poland that was first detected in Lancaster County, Pennsylvania, in December 2015. - Articles
Mid-Atlantic Commercial Vegetable Production Recommendations (Sections)
This article contains the individual sections of the Mid-Atlantic Commercial Vegetable Production Recommendations Guide as downloadable PDFs. - Guides and Publications
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Mid-Atlantic Commercial Vegetable Production Recommendations
This guide, updated in February 2024, contains vegetable production information based on university, extension, and industry research, experience, and knowledge. - Articles
Invasive Insect: Thrips parvispinus
Thrips parvispinus is an invasive insect that can cause significant damage to various plants and agricultural crops. - Articles
Potato Production
With many varieties and high consumer consumption, potatoes fit well with many small growers and can be marketed through various outlets. - Articles
Garlic Production
Garlic is a crop that is well suited to a small acreage or as part of a larger direct marketing operation looking to diversify its mix of crops. - News
Environmental Protection Agency Mitigation Proposal Update: Ziram/Thiram/Ferbam
Date Posted 12/12/2023The first week in December 2023, the EPA hosted a webinar to address concerns and outline new measures for mitigating risks pertaining to using three commonly used fungicides: ziram, thiram, and ferbam. - News
¿Tienen estas plantas de tomate manchas de septoria o de tizón temprano?
Date Posted 12/4/2023A finales de Julio, nuestras plantas de tomate en la Granja de Investigación HortÃcola de Penn State en Pennsylvania Furnace comenzaron a mostrar signos de enfermedad ¿Que sÃntomas observamos? - News
Do These Tomato Plants Have Septoria Leaf Spot or Early Blight?
Date Posted 12/4/2023In late July, our tomato plants at Penn State’s Horticulture Research Farm in Pennsylvania Furnace began showing disease symptoms. But what disease symptoms were we seeing? - News
Los daños de la chinche apestosa marrón marmoleada en tomate
Date Posted 12/1/2023Nuestro equipo ha estado estudiando y evaluando diferentes variedades de tomate, y por segundo año consecutivo, hemos visto daños en los frutos producidos por la chinche apestosa marrón marmoleada, Halyomorpha halys. - News
Brown Marmorated Stink Bug Damage on Tomato
Date Posted 12/1/2023We’ve been evaluating tomato cultivars, and for the second year in a row, we’ve seen brown marmorated stink bug damage on the fruit. - Webinars
Produce Grower Update: Weed Management in Sweet Corn
Length 2 hoursJoin us as we cover herbicide programs and integrated tactics, like cover crops, to handle weeds in sweet corn production. - Webinars
Produce Grower Update: Wilting in Cucurbits
Length 2 hoursLearn to identify the cause of why your cucurbits are wilting by using deductive logic and diagnostic techniques. Discover effective solutions, including chemical and alternative methods, to manage this issue. - Articles
Sources Of Plant Disease In Greenhouses
Where do diseases begin? It is important to prevent losses due to plant pathogens by reducing or eliminating the numbers of pathogens at their source. - Articles
Evidence of Tobacco and Tomato Hornworm on Tomatoes
We can see evidence of hornworms in our tomato fields during the growing season. Sometimes, the only clue is droppings on a few leaves of the plants. - News
2023 PA Vegetable and Berry Current Issues for September 13
Date Posted 9/13/2023This is the last report for the 2023 season. - News
2023 PestWatch Report for September 6
Date Posted 9/6/2023The corn earworm moth catch was variable again this week. - News
2023 PestWatch Report for August 30
Date Posted 8/30/2023The corn earworm moth catch was variable across the state this week. - News
2023 PA Vegetable and Berry Current Issues for August 30
Date Posted 8/30/2023Downy mildew on butternut squash and jack-o-lantern pumpkin was reported this past week in eastern PA and northern N.J.