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…]
Dan Egel
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…]
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…]
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…]
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…]
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…]
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 common[Read More…]
This disease can cause loses by the wilt and decline of plants. This article describes the symptoms and management of two similar diseases of potato both known as black leg caused by different bacterial pathogens. Both black leg diseases have similar symptoms. Often the first symptom one might observe is reduction in plant emergence. After[Read More…]
Many years ago, I was told that to successfully use fungicides on vegetables, one must use high spray pressures and hollow cone nozzles. However, I had trouble finding any research on this topic, just rumors. So, I did my own research. Dennis Nowaskie, Superintendent at the Southwest Purdue Agricultural Center (SWPAC) built a single row[Read More…]
MELCAST is a weather-based disease-forecasting program that helps growers schedule foliar fungicides applications for watermelon and cantaloupe. MELCAST stands for MELon disease for CASTer. This program, designed by Dr. Rick Latin, Professor of Plant Pathology at Purdue University, keeps track of weather conditions so that cantaloupe and watermelon growers can apply foliar fungicides to their[Read More…]