- Late Blight: There have been scattered reports of late blight in the Northeast region the last few weeks. There have been no reports of late blight in New Jersey to date this summer.
- Cucurbit Powdery and Downy Mildew remain active. All cucurbit growers in the state should include powdery and downy mildew specific fungicides in their weekly maintenance programs. As a reminder, all abandoned fields need to be disced under or sprayed with gramoxone to reduce inoculum pressure.
- Pepper Anthracnose has been reported in some areas. See Mitigating Losses to Pepper Anthracnose for more information on its control.
- Bacterial problems on tomato and pepper continue to be an issue. The dry weather this past week should have helped slow things down, however, heavy rain is expected in the state on Tuesday.
- Results of a Septoria Leaf Spot trial on parsley this summer at RAREC suggest that resistance is beginning to develop to the FRAC code 11 fungicide, Quadris, and are similar to results from a trial last fall (see Controlling Septoria Leaf Spot in Parsley). Parsley growers, particularly in the Vineland area, should consider using fungicides such as Fontelis (penthiopyrad, FRAC code 7) or Merivon (fluxapyroxad + pyraclostrobin, 7 + 11) in weekly rotations.
August 10, 2014 Andy Wyenandt
Vegetable Disease Briefs – 8/11/14
July 23, 2014 Andy Wyenandt
Late Blight on Tomato in Virginia
Late blight was reported on tomato in Leesburg, Virginia on 7/21. Leesburg is Northwest of Washington, DC. There have been scattered reports of late blight in the region this summer.
This is a good reminder for all tomato and potato growers in New Jersey and surrounding region to scout on a regular basis. No late blight has been reported in New Jersey to date. For more information on late blight and to track its progress in the US please visit USAblight.
July 22, 2014 Andy Wyenandt
Cucurbit Downy Mildew Confirmed in Southern NJ – 7/22/14
Cucurbit downy mildew was confirmed in a 10 acre cucumber field near Rosenhayn in southern New Jersey today.
This is the first report of cucurbit downy mildew in New Jersey this growing season. All commercial cucurbit growers in the state and region should scout their fields on a regular basis. Growers who have not already included downy mildew specific fungicides into their weekly fungicide programs should do so immediately.
Symptoms of cucurbit downy mildew
on cucumber leaf.
If left uncontrolled, cucurbit downy mildew will cause significant losses. For more information on controlling cucurbit downy mildew please see the 2014 Commercial Fungicide Recommendations Guide.
Organic growers can apply copper and other OMRI-labeled products at labeled rates to help suppress downy mildew development under light disease pressure.
July 19, 2014 Andy Wyenandt
Vegetable Diseases of the Week
Southern Blight on Tomato
Note the small, spherical fruiting bodies (sclerotia) developing on the surface of the stem. The sclerotia can survive in the soil for many years without a host.
Southern blight on infected tomato stem.
White Mold on Cabbage
White mold on cabbage producing large, black fruiting bodies (sclerotia). The sclerotia can survive in the soil for many years without a host present.
White Mold on Cabbage
July 19, 2014 Andy Wyenandt
Vegetable Briefs – 7/19/14
Basil downy mildew
Basil Downy Mildew remains active in New Jersey. All basil growers should scout on a daily basis and taking appropriate preventative measures.
Cucurbit downy mildew
Cucurbit Downy Mildew has been reported as far north as northern Maryland and in central Michigan to-date. With the latest weather this past week, all cucurbit growers should scout on a regular basis and adjust fungicide programs accordingly and begin to apply downy mildew specific fungicides if not already done so. Organic growers should apply copper or other OMRI-approved products to help prevent and suppress downy mildew development. If you suspect CDM on your farm please contact your count agent so we can confirm and report it. To track downy mildew in the US please visit NCSU’s Downy Mildew Forecasting Website.
Cucurbit growers should scout on a regular basis and adjust fungicide programs to incorporate powdery mildew specific fungicides into their weekly fungicide programs.
Peppers and Tomatoes
Bacterial leaf spot has been reported on both crops. Heavy wind and rains have been experienced throughout the state. Remember that all bacteria need a natural opening (i.e., stomata) or a wound (i.e., from typing or pruning) to enter a plant to start an infection.
[Read more…]
July 19, 2014 Andy Wyenandt
Don’t Rely on Disinfestants for Disease Control
The hot, wet weather this past week brought with it heavy winds and rain to many areas and spikes in reports of Phytophthora blight and bacterial problems on tomato and pepper. In general, this type of weather is ideal for the development and spread of many vegetable diseases.
By now most growers are on weekly protectant fungicide programs to help prevent disease development. It’s important to remember at this point in the season when disease pressure is high that growers stick with their standard fungicide programs.
Growers should not replace fungicides with disinfestant-type products in their weekly fungicide programs.
Remember, the disinfestants only kill what they come into direct and immediate contact with and do not offer any residual activity like fungicides do. Disinfestants should be used in conjunction with weekly fungicide programs and be applied based on specific weather events such as following rainfall or overhead irrigation or after certain cultural practices such as tying or pruning where plant injury or wounding may occur.
