What is in this article?:
- Hessian fly resistance a threat to Southeast wheat
- Pay attention to recommendations
- Use distance to advantage
• Many of the varieties that contain genes that make wheat resistant to Hessian flies and/or Hessian fly damage are not working in the Southeast.
Pay attention to recommendations
North Carolina State University Small Grains Specialist Randy Weisz says the USDA study indicates growers in the upper Southeast should pay careful attention to the “Wheat Variety Performance & Recommendations” SmartGrains newsletter that is published every July by North Carolina State University.
“We rate varieties every year for resistance to the specific Hessian fly populations present in North Carolina, and publish those ratings in this newsletter to help growers keep up-to-date on which varieties are the best,” Weisz says.
The newsletter is available from North Carolina county Extension offices and on line at: www.smallgrains.ncsu.edu/_SmartGrains/No28VarietySelection2010.pdf.
Weisz adds, “Variety resistance is the best defense against Hessian fly. There is a really good visual demonstration of how powerful variety resistance is in Photo 10-15 in the new production guide. The photo can be seen on line at: http://www.smallgrains.ncsu.edu/_Pubs/PG/Insects.pdf.
For the 2011 crop, he says the best management for Hessian flies in late winter and the spring is to check fields prior to top-dress time. If a wheat field looks healthy and is thickly tillered, Hessian fly will almost certainly not be an issue.
Hessian fly infestations are easy to identify. Fields with fly damage are thin, poorly tillered, and have plants that appear sick or that have died.
Pulling up a sickly plant, and peeling back the leaves will usually reveal Hessian fly pupae that look like small brown grains of rice, or seeds.
Fields with evidence of Hessian fly damage might benefit from a spring application of a long-residual pyrethroid. However, the application must be made close to the time the spring generation of adults emerge from the pupae, usually in mid-March.
Because the success of this rescue control measure is so dependent on correct timing, it is not always effective.
Growers with a serious Hessian fly problem in the spring, should look over the recommendations given below, to help prevent a future reoccurrence.
For Virginia-Carolina growers, prior to planting wheat this fall, some factors to consider for optimum Hessian fly management are:
Because the Hessian fly life cycle is largely dependent on the presence of wheat stubble, rotations which prevent new wheat from being planted into or near a previous wheat crop’s stubble will be the most effective way to prevent infestations. Growers should avoid planting wheat into last season’s wheat stubble. Continuous no-tillage, wheat-double-cropped-soybeans may result in severe problems and should be avoided in Hessian fly problem areas.