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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 April 30, 2004 - Painter, VA
James T. Custis (Farm Manager, ESAREC)
Rain late pm Friday 4/23 and again Monday pm into Tuesday pm for a total of 1.07". Maximum air temperature of 84 and minimum of 43 and soil temperatures in the low to mid 60's for highs and low to mid 50's for lows at 2 and 4 inches. The rain has slowed field work some but it was needed in some crops. It looks like we may get some more rain late in the weekend and into the first of the week.
Blacklight and Pheromone Insect Traps
Jack Speese & Tom Kuhar (ESAREC)
Blacklight trap (BLT) in Painter, VA: (still a little cool at night) 0 cutworm moths, 1 ECB moth, 0 stinkbugs
BLT in Cheriton, VA: no trap data this week (rain storms and other problems)
Potato Disease Update
Christine Waldenmaier (ESAREC)
The local potato fields that I have visited are looking exceptionally good this year with even stands and good color. When a crop looks pretty like this, it can be tempting to apply fungicide just to insure that it stays pretty. For this reason alone many acres are sprayed with fungicides when they aren't necessarily needed.
Weather conditions are extremely important in disease development. Windy, dry conditions may prevent disease development better than any fungicide. For this reason fungicides applied during windy dry conditions look like they are working great! This is where disease forecasting can help with timing a fungicide application. We have weather monitors running at six locations on the Eastern Shore of Virginia and we are currently running disease models for late blight and early blight. Since April 15th we have accumulated only 6 late blight severity values (DSV) in Capeville, 4 DSV in Northern Accomack County and 2 DSV in Painter. The late blight model calls for a spray at 18 DSV. Only 2 severity values have accumulated for the early blight model, and that calls for a spray at 25 DSV. With weather looking fairly dry in the extended forecast, holding off on the fungicide spray may save time, money and wasted chemical.
Northampton County news from our roving reporter in the field
(Bill Shockley (VCE, Northampton Co.)
We have a distinct increase in cereal leaf beetle activity in small grains, with larger numbers of adults in the light trap. Large populations of aphids and some powdery mildew in wheat are also being observed. Fungicide and insecticide applications are being made to small grain in some instances. As temperatures increase, scouting should begin for thrips activity in newly emerged string beans. We have received approval for the use of Reflex for string bean application, more information will follow.
Black cutworm activity in potatoes
Tom Kuhar (ESAREC)
At the research station in Painter we have noticed some black cutworm damage in potatoes (maybe 1-5% of plants). The insect appears to be in its final instar (late larvae), which is also the stage in which 80% of its feeding damage appears, and when it will cut down young plants. Black cutworms feed at the soil level and do not climb plants like some other later-occurring cutworm species. Be on the look out for this pest in your crops. Large larvae burrow in the soil and are difficult to find. The most apparent sign of black cutworm infestation is damaged plants with stems completely or partially severed. A pyrethroid spray is typically recommended for control of cutworm infestations in most crops, including potatoes.
Asparagus beetles active
Tom Kuhar (ESAREC)
Asparagus beetle adults are active on our asparagus spears in Painter, VA. We seem to be seeing more this year than last year. Watch for the dark oblong beetle eggs that are laid in clumps and protrude out on the spears. A control treatment is recommended if 2% of the spears are infested with eggs or if 5% of the plants are infested with adults. Asparagus beetles are not hard to kill, but on the same token, not many newer insecticide products are labeled on the small acreage crop. The broad-spectrum oldies-but-goodies, Sevin, Lannate, Ambush, or Pounce will provide control. For more info on asparagus beetles, please see the VCE Fact sheet: http://www.ext.vt.edu/pubs/entomology/444-620/444-620.html
Zeal - new miticide for fruit crops
Information provided by John Cranmer (Valent)
Zeal - This new material from Valent is now available for mite control in apples, pears and strawberries. It is also labeled for lygus bug and spittle bug control on strawberries. It is a reduced risk insecticide which acts as an insect growth regulator against all stages of spider mites and European red mites. The active ingredient is etoxazole, which is a molting inhibitor. It also has translaminar activity. The use rate is 2-3 oz/acre. The days to harvest after an application to strawberries is one day.
Virginia Small Grains Association Field Day
Ellen Davis (VA Small Grains Association)
The Virginia Small Grains Association Field Day will be held May 20, 2004 in Warsaw, VA. If you have questions or need additional information please contact Bob Pitman, Superintendent, Eastern Virginia AREC at 804/333-3485, rpitman@vt.edu or Ellen Davis, Executive Director, Virginia Small Grains Association at 804/843-4456, eded@inna.net. A tentative agenda has been set and a program can be e-mailed to you upon request.
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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