What is in this article?:
- Burrower bugs hit record levels in Georgia peanut crop
- South Carolina research
• While burrower bugs may be a new problem for many growers, burrower bug damage has been a major problem for the U.S. peanut industry, especially for salted nut manufacturers, in both domestic and export markets.
• What we currently know and expect is for burrower bugs to be more of a problem in conservation or reduced-tillage, non-irrigated fields. Tillage is likely to disrupt early season burrower bug numbers and they seem to resort to feeding on peanut kernels more in drought conditions.
South Carolina research
Research conducted in South Carolina by Jay Chapin, Clemson entomologist, demonstrates an association between burrower bug feeding and aflatoxin contamination. His research showed alflatoxin concentration was 65 times greater in kernels with burrower bug feeding.
Obviously, irrigation is the best insurance in preventing burrower bug feeding, but approximately 40 percent of Georgia’s peanut crop is non-irrigated.
The future of Georgia’s non-irrigated peanut acres may be found in the past. Growers have gotten away from deep turning peanut land with the adoption of conservation-tillage, but there is a place for both in peanut production. We believe growers need to seriously consider deep turning peanut ground in the fall after harvest and then planting a cover crop. We realize it is difficult planting a cover crop behind deep turning but the benefits will be worth the extra effort.
Let’s look at the benefits of deep turning peanut ground. First, damage potential from burrower bug is significantly reduced when fall tillage is used to plant cover crops compared to no-till planting of cover crops.
Another important benefit of deep turning is that Palmer amaranth (pigweed) emergence has been reduced 45 to 60 percent in recent Georgia tillage studies. Deep turning combined with a good cover crop has reduced Palmer amaranth emergence by up to 95 percent. Deep turning also reduces other troublesome weed emergence, most notably tropical spiderwort.
In many situations (but not in all), deep turning can greatly reduce white mold and other soil-borne diseases which can lead to significant yield increases due to just disease control. Disease control and yield increases will be more likely in fields with poor rotation or history of disease.
The best defense against burrower bugs is irrigation and tillage, but South Carolina research has shown granular Lorsban (chlorpyrifos) applied at pegging has helped suppress burrower bug injury.
It is important to note that rainfall or irrigation within seven to 10 days is necessary to activate chlorpyrifos. The longer the chlorpyrifos granules lay on the ground, especially during the hot weather we traditionally have at pegging, the less effective the chlorpyrifos will be.
Other benefits of chlorpyrifos (assuming timely activation by either rainfall or irrigation) include control of lesser cornstalk borer, Southern corn rootworm and a significant reduction in both wireworms and their damage. Wireworms are a significant problem in Coffee County reducing both yields and peanut quality in many fields. Chlorpyrifos may also aid in the suppression of white mold and three-cornered alfalfa hoppers.
The disadvantages of chlorpyrifos, besides the cost and the necessity of timely rainfall to activate it, include the increased risks of tobacco budworm, corn earworm, fall armyworm, cutworm and spider mite outbreaks.