Downy Mildew and Garden Diseases On the Rise
Excessive rains experienced in July and August coupled with humidity exacerbate fungal, water mold and bacterial infections of plants in our gardens. Downy mildews caused by different water molds are thriving at this time and damaging crops. If you see cucumber or butternut squash leaves quickly turning into a yellow, angular shape from the top, you may suspect a downy mildew caused by one of these pathogens belonging to water molds.
Dr. Zelalem Mersha, VSU plant pathologist, has established sentinel plots to monitor the disease on cucurbits and alert growers about the onset of the disease. In 2019, the disease was confirmed in Chesterfield County on July 8. In 2020, planting on the sentinel plots was delayed until July 1 due to the Covid-19 pandemic, but the disease was recently reported August 8 on the web platform (https://cdm.ipmpipe.org/).
Gardeners and farmers with sizable cucurbit production in central and southern Virginia can either contact Dr. Mersha (zmersha@vsu.edu or 804 524-2694) or their local extension office to report the disease. At this critical time where many diseases already may be prevailing in gardens, it is highly advised to select the right fungicides and bactericides when acquiring biological or synthetic products from local retailers.