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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 21, 2004; Painter, VA
James T. Custis (Farm Manager, ESAREC)
WARM, DRY and WINDY for much of the week, then NICE, COOLER and 6/10" RAIN!!!!
We had 0.02" rain last Sunday pm and no other rain until Wednesday pm when we got 0.60" . Highs each day of 84 F and lows of 66 to 71 F Friday to Wednesday and Thursday was much cooler, high during the day of 68 F and a low of 62 F. We welcomed the rain.
Blacklight and Pheromone Insect Traps
Jack Speese & Tom Kuhar (ESAREC)
Weekly catch:
Blacklight trap (BLT) in Painter, VA: 16 European corn borer moths, 3 cutworm spp., 2 true armyworm, 1 corn earworm, 23 green stink bugs,
BLT in Cheriton, VA: 187 ECB moths, 21 cutworm spp. (mostly black cutworm), 3 corn earworm, 2 true armyworm, 4 green stink bugs
In summary, the first generation European corn borer moth flight is still fairly high on the Eastern Shore and green stink bug adult activity has dropped a little from last week.
Reflex Herbicide Receives Section 18 Registration for Snap Beans in Virginia
(Henry Wilson & Jason Sanders, ESAREC)
We are pleased to announce that we have received approval from the EPA for the use of Reflex for post-emergence weed control in snap beans in Virginia. This registration pertains to the 2004 crop. Our research indicates that Reflex affectively controls numerous broadleaf weeds in snap beans when mixed with 1 qt of non-ionic surfactant per 100 gallons of water. Since Reflex is not highly effective on common lambsquarters, our data support reducing the Reflex rate to 0.5 pt/A and adding 1 pt/A of Basagran herbicide. Some temporary snap bean response may occur with the use of Reflex, but snap beans recover rapidly and weed control has been good. Plan to time the application between the one and three trifoliate growth stages. A copy of the supplemental label can be obtained by e-mailing Dr. Henry Wilson at hwilson@vt.edu.
Northampton County news from our roving reporter in the field
(Bill Shockley (VCE, Northampton Co.)
Some armyworms have been located in lower Northampton County in barley. They were found under lodged straw and seem to be feeding on existing ryegrass.
This particular field has not had a previous insecticide application. Growers need to scout fields of barley and wheat for potential problems. We are seeing some thrip activity in string beans also. Some growers are applying combinations of Reflex and Basagran for early weed flushes, and are adding an insecticide. Some injury has been observed on these applications made during the hot periods of the day. Also, a reminder to string bean growers that the Reflex special label (which was recently sent out) states "Do Not Apply Within 30 Days of Harvest". Be sure to count your days...
Bean leaf beetles on snap beans
Tom Kuhar (ESAREC)
I am getting some calls from growers on the Shore about bean leaf beetles on early-stage snap beans. This insect feeds on a wide variety of legume hosts, including the foliage and pods of snap beans and soybeans. Bean leaf beetles can show up on plants overnight, and defoliate young bean seedlings. Adults prefer young plant tissue. Leaf damage appears as holes of varying sizes. Pyrethroids such as Warrior, Capture, and Mustang Max have worked well for control of bean leaf beetles in recent trials at the ESAREC in Painter, VA.
Bean seeds that were pre-treated with Cruiser (thiamethoxam) should provide effective control of bean leaf beetle foliage feeding, as well as control of thrips, whiteflies, and potato leafhoppers.
Potato Disease Control
Christine Waldenmaier (ESAREC)
The hot, dry weather in the beginning part of this week helped to stall disease progress. In the past two days we've seen a dramatic break in the weather and disease severity values have started to climb again. Growers who have not yet applied a preventative fungicide should now do so.
Wheat Disease Control
Christine Waldenmaier (ESAREC)
Powdery mildew - Wheat variety trials planted on the Research Station have been rated for powdery mildew infection. Tolerant varieties showed very little disease infection on the F1 leaf and none on the flag leaf. Susceptible varieties had F1 leaves coated with mildew, however very little has moved up onto the flag leaf. In general, leaf rust was scarce and Septoria leaf spot low-moderate throughout.
Insect management in potatoes
Tom Kuhar (ESAREC)
We are seeing a relatively high density of European corn borer egg masses on potato plants in Painter and in upper Accomack County. Tunnel injury to leaf axils is also apparent. A single egg mass can yield 20 or more neonate ECB larvae in approximately 4 days. Potato plants can withstand a moderate amount of ECB tunneling before yield loss occurs, but given what we are seeing with egg densities in the field and the high moth catch that we are picking up at blacklight traps, I would recommend an insecticide application for ECB control on potatoes at this time, particularly if a fungicide spray is going on anyway. The economic (action threshold) is to apply first spray when 10% of the stems have entry holes in fresh market varieties or 25% in processing varieties. Avaunt, Ambush, Baythroid, Furadan, Penncap, Pounce, Monitor or Spintor will provide effective corn borer control when applied in a timely manner. A follow-up spray may be needed in a week or two.
Colorado potato beetles are still actively laying eggs with small and large larvae feeding away on plants that were not treated with Admire, Platinum, Gaucho, or Cruiser. If potatoes were not treated with any of the aforementioned products at planting then fields should be scouted weekly. A control measure is recommended if 50 CPB adults or 200 larvae are found per 50 randomly-sampled plants. Effective foliar products for CPB in Virginia include: Provado, Actara, Leverage, Avaunt + PBO, SpinTor, AgriMek, and Kryocide. Btt and azadirachtin (neem oil) products also work effectively if small larvae are sprayed in a timely manner.
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 ARECs website at http://arecs.vaes.vt.edu/arec.cfm?webname=painter.
Information request from VA Ext. Agents
Tom Kuhar (ESAREC)
To Virginia Cooperative Extension Ag. agents, we would love hear from you regarding crop pest activity in your county or region. Send me a quick e-mail by the end of the day on Thursdays. Passing on your information or observations may help other growers and agricultural workers around the state. Thank you.
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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