• Basil downy mildew has been reported near Vineland!
• Bacterial leaf spot has been reported on tomato.
• Phytophthora blight has been reported on summer squash.
• No late blight has been reported in the region to date. The Late blight found in greenhouse tomatoes in WV two weeks has been reported to be US23. To track late blight in the US please visit http://usablight.org/
• Want more information on what’s going on, please sign up for the Jersey Vegetable Crop Ag Updates at: http://jerseyvegcropsagupdates.blogspot.com/.

Vegetable Disease of the Week

Symptoms of downy mildew on
infected sweet basil leaf

Basil downy mildew sporulating on the
underside of an infected leaf.

Rob Pyne¹, Kathryn Homa ^1,2, Bill Barney^1,2, Andy Wyenandt¹, and Jim Simon^1
1 Department of Plant Biology and Pathology, Rutgers University  ² IR-4 Program

In 2010 a basil variety and breeding line trial was conducted as an initial screen for potential sources of genetic resistance to downy mildew caused by Peronospora belbahrii, a destructive pathogen of basil introduced in the US in 2009. This trial was expanded from 30 to over 40 varieties representing six different Ocimum species in 2011. Varying levels of disease susceptibility were observed with the highest tolerance associated with O. americanum, O. citriodorum, O. gratissimum, and O. tenuiflorum varieties and USDA-GRIN accessions. In contrast, the most severe symptoms and extensive sporulation were consistently observed in O. basilicum accessions, including the popular commercial sweet basil varieties. [Read more…]

Basil downy mildew has been reported in South Jersey near Vineland. This is the first report of basil downy mildew this season in New Jersey and the mid-Atlantic region. All basil growers are urged to scout their fields and consider applying preventative fungicides. The wet weather over the past week and the rains expected to come through the area later today and this later week are ideal for the development and spread of basil downy mildew.