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Edited by Tom Kuhar, Assistant Professor, Dept. of Entomology, Virginia Tech
Greetings crop producers, researchers, extension personnel, and crop consultants,
Weather summary for week ending May 28, 2004; Painter, VA
James T. Custis (Farm Manager, ESAREC)
WARM but TIMELY RAIN came Tuesday pm and Wednesday am and pm. Total rain for the week was 0.82". NICE, no irrigation this week!!! Highs each day mid to upper 80's and lows upper 60's to low 70's. We welcomed the rain again even though it slowed field work!
Blacklight and Pheromone Insect Traps
Jack Speese & Tom Kuhar (ESAREC)
Weekly catch:
Blacklight trap (BLT) in Painter, VA: 31 European corn borer moths, 5 cutworm spp., 1 true armyworm, 2 corn earworm, 20 green stink bugs, 1 brown stink bug
BLT in Cheriton, VA: 12 ECB moths, 5 cutworm spp. (mostly black cutworm), 3 corn earworm, 1 true armyworm, 1 green stink bug
In summary, the first generation European corn borer moth flight appears to have dropped off a little from last week in Northampton Co. (Cheriton), but remained the same in the central peninsula (Painter). Green stinkbug catch also dropped a little from last week.
Potato Disease Control
Christine Waldenmaier (ESAREC)
Blightcast - We have accumulated 18 Disease Severity Values, the trigger point for a fungicide spray for late blight in all regions of the Eastern Shore. After the first fungicide spray the recommended spray interval is based on rainfall and severity values. The following chart was developed for regions where late blight has been detected in the area. This may help determine when you have to reapply fungicide:
Total rain for the past 10 days
Total DSV in the past 7 days
Spray interval in days
more than 1.2 inches <3 10
more than 1.2 inches 4-6 or more 5-7
less than 1.2 inches <3 14
less than 1.2 inches 4 10
less than 1.2 inches 5 or more 7
Tomato spotted wilt virus in tomatoes
Christine Waldenmaier & Tom Kuhar (ESAREC)
Tomato spotted wilt has been observed in commercial tomatoes on the Eastern Shore and also in Southeast Virginia according to Dr. Pat Phipps, Plant Pathologist at the Tidewater AREC. Incidence of this virus will probably increase as the thrips populations increase throughout the season. Be on the lookout for this plant disease in tomatoes, peppers, peanuts, potatoes, and tobacco. The virus is vectored by thrips. In Virginia, the primary vector is tobacco thrips, Frankliniella fusca. There is no cure for the virus, once plants are infected. Early symptoms of spotted wilt on tomato are difficult to diagnose. Young, infected plants may show an inward cupping of leaves, and the foliage may appear off-color or have a slight bronze cast. As the disease progresses, plants may develop dark brown to black streaks on the main stem. Occasionally the top portion of the plant appears yellow and wilts. The most characteristic symptom of spotted wilt appears on the fruit. On young fruit, white to yellow concentric rings, one-half inch in diameter, develop on the fruit skin. The area within the ring typically is raised, which gives the fruit a bumpy or warty appearance. The bright yellow rings on red, mature fruit are quite striking and are easily diagnosed as spotted wilt.
Management of the disease is difficult.
Thrips vectors continuously move into tomato fields from weeds or other crops that may harbor the virus. We know of one commercially-available tomato variety that grows well in Virginia that is resistant to TSWV:
Amelia VR, formerly HMX 0800, by HarrisMoranSeeds (http://www.harrismoran.com/products/tomato.htm)
According to the company description,
Amelia VR combines an armor-plate disease package along with high fruit quality and high yields. Multiple disease resistance, including TSWV and fusarium F3. Firm and aromatic fruit, ideal for green and vine ripe harvest. Crack tolerant skin. Vigorous determinate plant with an excellent leaf canopy, and well adapted to stake culture. This new tomato produces a vigorous plant that can yield extra large and large-sized fruit. Harris Moran field testing shows it performs best under moderate to heavy pruning. Dr. Herman Hohlt (ESAREC, emeritus) tested this variety on the Eastern Shore a couple years ago and it yielded well.
Regarding TSWV management, here is some information based on scientific research studies:
Northampton County news from our roving reporter in the field
(Bill Shockley (VCE, Northampton Co.)
TWILIGHT SMALL GRAINS TOUR Painter Station Friday June 4, 2004 at 5:30 PM.
Program will include research plot-work on ryegrass control and variety test.
Light dinner and refreshments will be served. If you want to eat, call the
Northampton County Extension Office at 757-414-0731 so we can get a head count.
We are seeing quite a few bean leaf beetles on snap beans.
Eastern Shore AREC Field Days, June 28 & June 29
Henry Wilson (ESAREC)
Please come and join us for the Eastern Shore Field Day and Weed Tour, held at the Virginia Tech Eastern Shore Agricultural Research and Extension Center (AREC), Painter, VA. The Field Day starts at 4:30 p.m. on June 28 with tours of research in vegetables, including potatoes and snap beans, and a BBQ dinner will be provided following the tours. The Weed Tour starts at 9:00 a.m. on June 29, and includes weed management research in corn, cotton, potatoes, soybeans, snap beans, and wheat. For more information contact Jason Sanders (757-414-0724 ext. 42 or jcsander@vt.edu) or Henry Wilson (757-414-0724 ext. 13 or hwilson@vt.edu). Information can also be obtained from the Eastern Shore AREC's website at http://arecs.vaes.vt.edu/arec.cfm?webname=painter.
Virginia Vegetable, Small Fruit and Specialty Crops Newsletter
Tom Kuhar (ESAREC)
For those of you who may be unaware, but who deal with vegetable, small fruit, and other specialty crops, Virginia Tech has a bi-monthly electronic newsletter edited by Dr. Tony Bratsch (Dept. Horticulture) entitled: Virginia Vegetable, Small Fruit and Specialty Crops Newsletter. It is located at the following URL: http://www.ext.vt.edu/cgi-bin/WebObjects/Docs.woa/wa/getnews?cat=tt-news-vg
Thomas P. Kuhar
Assistant Professor
Department of Entomology
Eastern Shore Agricultural Research & Extension Center
Virginia Polytechnic Institute & State University
33446 Research Drive
Painter, VA 23420
E-mail: tkuhar@vt.edu
Tel: 757-414-0724
FAX: 757-414-0730
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