3Gummy stem blight is an important disease of cucurbits in the Midwest. Gummy stem blight can cause lesions on leaves and stems of cantaloupe, watermelon and other cucurbits. Fruit lesions may be observed on pumpkin and, occasionally, on cantaloupe. Fruit lesions are known as black rot. Find more information about gummy stem blight and black…Read more about Gummy Stem Blight Fungicides[Read More]
Plant Disease Management
As vegetable growers get ready for the 2022 season, one question might be to find up-to-date information about fungicides and how to apply them. Some possible resources are listed below. The Midwest Vegetable Production Guide for Commercial Growers offers recommendations for fungicides and other pesticides and practices that have been updated for the 2022 season. The guide,…Read more about Pesticide Information for 2022[Read More]
The photo here (Figure 1) shows a spaghetti squash with many lesions on the fruit. At first glance, it may seem to be several lesions of different sizes. However, if one looks closely, there are actually two different diseases on the fruit. The larger, brown, irregular water-soaked areas are black rot, caused by the same…Read more about Two Diseases of Spaghetti Squash[Read More]
Bacterial canker has been observed in late season tomato crops. This article will serve as a review of this important disease. The symptoms of bacterial canker vary considerably. In most cases, the edges of the leaves may turn yellow and/or brown. That is, the margins of the leaves may become chlorotic and/or necrotic (Figure 1)….Read more about Bacterial Canker of Tomato[Read More]
In 2015 and 2018, I observed Cercospora leaf mold of tomato in high tunnel operations. In Hotline articles in those years, I noted that Cercospora leaf mold is normally a subtropical disease. This disease has again been observed in 2021 on tomatoes in high tunnels. I’m still not certain of the importance of this disease…Read more about Tomato Leaf Mold Diseases[Read More]
Dr. Margaret McGrath’s lab from Cornell University has developed a great resource for growers interested in using biopesticides to manage vegetable diseases. https://www.vegetables.cornell.edu/ipm/diseases/biopesticides/ This article provides a general introduction of biopesticides, major types of biopesticides, and the pros and cons of using them. The website also lists representative biopesticide products that are available for managing…Read more about Resources for Biopesticides for Vegetable Disease Management[Read More]
Downy mildew of cucumbers has been observed in Knox County. This disease has not been observed on pumpkins, but it is possible for downy mildew to spread from cucumbers to pumpkins. Therefore, pumpkin growers should scout for downy mildew and manage for the disease depending on their situation. Pumpkin growers who plan to harvest mid…Read more about Downy mildew of Pumpkin: What to Look for[Read More]
In the last several days I have received complaints of pumpkin plants with yellow leaves. Growers want to know if the yellow is a symptom of disease and what can be done about it. Yellow lesions on leaves may be symptoms of disease. There can be many reasons why pumpkin plants have yellow leaves. Usually,…Read more about Yellow Leaves on Pumpkin[Read More]
Downy mildew has been observed in Knox County on cucumber. In addition, downy mildew on cucumber has been reported in central Michigan on cucumber and central and northern Ohio on cucumber and cantaloupe. The downy mildew race type found in Knox county that goes to cucumber and cantaloupe may also go to other cucurbits such…Read more about Cucumber Downy Mildew Found in Indiana[Read More]
Listed below are select foliar diseases of tomato. Early blight and Septoria leaf blight These diseases are listed together because, from a few paces away, the diseases appear similar. And the management for these diseases is similar. Together these diseases are probably the most common diseases of tomatoes in the field. One of the most…Read more about Foliar Diseases of Tomato[Read More]