Bacterial wilt is a serious pest of cucumbers and melons. This disease is caused by the bacterium, Erwinia tracheiphila. However, it is spread by the striped or spotted cucumber beetle. Most management schemes have concentrated on controlling the cucumber beetle in order to lessen the severity of bacterial wilt. Currently, management of bacterial wilt often…Read more about Susceptibility of Melon Varieties to Bacterial Wilt[Read More]
Plant Disease Management
This disease was identified on a long Asian cucumber growing in a high tunnel in Mid-June in Knox County. The first symptom noted was wilting of the cucumber plant. Upon closer examination, a light, gray necrosis was observed on the lower portion of the plant. In Figure 1, you may notice dark spots in the…Read more about New Disease Report – Charcoal Rot of Cucumber[Read More]
The following two articles describe two vegetable diseases new to Indiana that were recorded this past season. While neither of the disease reports are from severe outbreaks, it might be a good idea to become familiar with what may become a new disease situation. Target spot of tomato was identified from a tomato plant growing in…Read more about New Disease Report – Target Spot of Tomato[Read More]
Several pumpkin growers have asked me when to stop managing for pumpkin diseases. That is, when should a pumpkin grower stop applying fungicides? I cannot provide a definitive answer for this question; every grower will have to make his or her own decision. Below, however, are some factors to consider. Estimate the crop yield-walk through the field and…Read more about Late Season Pumpkin Disease Management[Read More]
Before writing this article, I went back to an old article from 2015. In 2015, I had written, Plectosporium blight was more severe than normal. In 2018, I have also observed more Plectosporium blight than usual. It is not clear to me why this disease seems to be more widespread compared to recent seasons. However,…Read more about Plectosporium Blight of Pumpkins[Read More]
Cucurbit downy mildew has been observed on cucumber in LaPorte County and LaGrange Counties, in northern Indiana and Knox County in the southwest. Downy mildew of cucurbits has also been reported in Kentucky and Michigan. See this article (https://vegcropshotline.org//article/cucurbit-downy-mildew/) in the last Hotline issue about details of downy mildew. Whether growers manage for downy mildew…Read more about Downy Mildew Update[Read More]
In the fall of 2015, I wrote an article for the Hotline about Cercospora leaf mold of tomato since this disease had been observed twice in the 2015 season. I wrote that Cercospora leaf mold was normally a subtropical disease. There have been several observations of Cercospora leaf mold on tomato in Indiana this year….Read more about Tomato Leaf Mold Diseases[Read More]
This disease was confirmed in Indiana recently. Cercospora blight initially causes small, oval, gray to tan lesions with red borders (Figure 1). If a 10X hand lens is used, dark flecks within the lesions may be observed; these flecks are where the spores of the causal fungus are produced. Severe infections may cause entire ferns…Read more about Cercospora blight of Aspragus[Read More]
Cucurbit downy mildew has been observed on cucumber in La Porte County and LaGrange Counties, Indiana. Downy mildew of cucurbits has also been reported in southern and central Kentucky. All cucurbit growers in Indiana should be scouting and managing for downy mildew. The organism that causes downy mildew of cucurbits doesn’t overwinter in Indiana. It has…Read more about Cucurbit Downy Mildew[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 about Spray Pressure and Nozzle Type[Read More]