Andy Wyenandt

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

June 30, 2014

Late Blight Reported in Erie County, NY and Cambria Couny, PA

Late blight was reported on potato in Erie County, New York and Cambria County, PA (west central) late last week. This is the first report of late blight in PA this season. There are also suspected cases of late blight are being reported on potato and tomato in Lancaster County, PA.

All tomato and potato growers in New Jersey should begin to scout their fields on a regular, if not daily basis. There have been no reported cases of late blight in New Jersey to date! However, all growers (conventional and organic) who have not initiated protectant fungicide maintenance programs should consider doing so. For organic growers, preventative copper applications should be considered. For more information on controlling late blight please see the 2014 Commercial Vegetable Fungicide Recommendations Guide.

Filed Under: Disease Forecasting Tagged With:
June 22, 2014

Late Blight Reported in Potato on Long Island

Late blight has been reported on potato on Long Island. This is the first report of late blight in the region to date. Potato and tomato growers should scout their fields on a regular, if not, daily basis and initiate their regular preventative fungicide programs if not already done so.

Filed Under: Vegetable Crops
June 21, 2014

Vegetable Disease of the Week – 6/21/14

Downy mildew sporulating on the bottom side of an infected collard leaf.
Note the white spore masses.
Collard-leaf-Downy-Mildew-1Collard-Leaf-Downy-Mildew-2

Filed Under: Vegetable Crops Tagged With: ,
June 21, 2014

Vegetable Disease Briefs – 6/21/14

  • Basil downy mildew has been reported in New Jersey. With current weather conditions all basil growers should scout on a daily basis and taking appropriate preventative measures.
  • Cucurbit downy mildew has been reported on cucumber as far north as central North Carolina as of 6/20. To track cucurbit downy mildew in the US please visit http://cdm.ipmpipe.org/
  • No late blight has been reported in the region. Late blight has been found as far as North Carolina to-date. To track late blight in the US please visit http://usablight.org/.
Filed Under: Vegetable Crops
June 21, 2014

Vegetable Disease Update – 6/21/14

Cole Crops

Downy mildew and Alterneria were confirmed on collard greens this past week. Current weather conditions are ideal for the development of both diseases on all cole crops as well as other crops.

Symptoms of downy mildew on cole crops include the production of white spore masses only on the undersides of infected leaves. The tops of leaves will develop slightly chlorotic (i.e., yellow) spots on the upper leaf surface that become papery in texture.

Alternaria typically starts out as small pinpoint spots on infected leaves that enlarge up to 2 inches. Lesions will become tan, brown or black and may have concentric rings and leave ‘shot holes’ in leaves.

Control of both diseases begins with regular scouting and preventative fungicide programs. Control of downy mildew is best with downy mildew specific fungicide such as Presidio (fluopicolide, 43) at 3.0 to 4.0 fl. oz 4SC/A, or Revus (mandipropamid, 40) at 8.0 fl. oz 2.08SC/A, or Zampro (ametoctradin + dimethomorph, 45 +40) at 14.0 fl. oz 4.38SC/A included in tank-mix with chlorothalonil (M5) at 1.5 pt/A. A phosphite fungicide (FRAC group 33) such as Prophyt, Rampart, or K-Phite can be included to also help control downy mildew. For control of Alternaria, apply chlorothalonil (M5) at 1.5 pt/A alone, or tank-mixed with a FRAC code 11 fungicide such as Quadris (azoxystrobin, 11) at 6.0 to 15.5 fl. oz 2.08F/A or Cabrio (pyraclostrobin, 11) at 12.0 to 16.0 fl. oz 20EG/A, or Fontelis (penthiopyrad, 7) at 14.0 to 30.0 fl. oz 1.67SC/A.

Filed Under: Vegetable Crops
June 13, 2014

Basil Downy Mildew Confirmed in New Jersey 6-13-14

Basil downy mildew has been reported for the first time this season near Millville, NJ in potted Thai and Cinnamon basil plants being sold at big box stores, as well as in sweet basil located in grower field. All basil growers in New Jersey should scout their fields on a daily basis. [Read more…]

Filed Under: Vegetable Crops Tagged With: