Andy Wyenandt

This is an archive of Dr. Wyenandt's posts on the Plant and Pest Advisory.

June 23, 2013

Vegetable Briefs and Update – 6/23/13

Vegetable Briefs

  • Cucurbit downy mildew was reported on cucumber in Caroline County, MD this Friday (6/21). This is the first report of CDM this year in the region. All cucurbit growers should scout their fields on a regular basis and consider adding downy mildew specific fungicides to their regular maintenance program.
  • Pith necrosis has been reported on tomato.
  • Basil downy mildew was reported near Vineland last week! All basil growers should continue to scout their fields and apply preventative fungicides.
  • Late blight was reported on tomato on the Eastern Shore of Virginia and in Montgomery County, MD this past week. These are the first reports of Late blight in the region this year.
  • 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 Update – 6/23/13

[Read more…]

Filed Under: Vegetable Crops
June 20, 2013

Late blight Reported on Tomato on the Eastern Shore, VA and in Maryland

Late blight was confirmed on tomato on the Eastern Shore of Virginia this afternoon and on tomato in Montgomery County, MD yesterday. All tomato and potato growers in New Jersey should scout thier fields on a daily basis and consider starting a standard weekly protectant fungicide program if one hasn’t already done so. No Late blight has been found in New Jersey to date. More more information on the control of Late blight please see the 2013 Commercial Vegetable Production Recommendations Guide. Organic growers should consider applying a OMRI-approved copper-based fungicide.

For more information and to track the progress of Late blight please USAblight.org.

Filed Under: Vegetable Crops Tagged With: , ,
June 18, 2013

Edema Developing in Some Brassica’s

Edema is being reported in some brassica crops. Edema is often expressed as off-color swellings or galls that appear on leaves and stems. Edema develops when epidermal cells hold excessive water due to a slowing of evapotransporation when hot, muggy days are followed cooler, wetter weather. Edema develops because the plant takes in more water (due to a high soil moisture content) than it can get rid of causing cells to rupture which results in the blistering of the leaves.

Symptoms of edema on collard leaf. Note the off-color appearance of leaf surface.

Symptoms of edema on top side of
collard leaf.
Note the off-color appearance of leaf surface.

Edema, bottom side of collard leaf. Note the irregular, 'corky appearance caused bythe rupture of leaf cells.

Edema, bottom side of collard leaf.
Note irregular, “corky” appearance due to
leaf cell rupture.

Filed Under: Vegetable Crops Tagged With:
June 13, 2013

Vegetable Briefs 6-14-13

  • 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.

Filed Under: Vegetable Crops Tagged With: ,
June 13, 2013

Vegetable Disease Update – 6/14/13

  • Basil
  • Pepper
  • Potato
  • Tomato

[Read more…]

Filed Under: Vegetable Crops
June 13, 2013

Breeding for Basil Downy Mildew Resistance

Rob Pyne1, Kathryn Homa 1,2, Bill Barney1,2, Andy Wyenandt1, and Jim Simon1
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…]

Filed Under: Vegetable Crops Tagged With: ,