David Owens, Extension Entomologist; owensd@udel.edu
Field Crops
Field corn and soybean insecticide recommendations have been updated and posted to the Extension webpage. Field corn: http://extension.udel.edu/ag/insect-management/field-corn/, soybeans: http://extension.udel.edu/ag/insect-management/soybeans/. Click on the link that says ‘Insecticide Recommendations.’
This update will not affect the QR-code functionality. The QR codes that you may have picked up at AgWeek will take you to the crop landing pages. From there, you can open the recommendation pdf. If you did not pick up a QR code card, we still have some left, just let me know which crops and how many you want.
The biggest changes in this year’s addition are the listing of soybean insecticidal seed treatments and the listing of ‘other labeled formulations’. In addition, the insecticide mode of action groups are listed as well as the signal word on the label that indicate the level of hazard with each product. The mode of action groups are general classifications, all of the insecticides in that group work in the same general way.
Field Corn
Wheat serves as an early season host for brown stink bugs, and the stink bug’s first generation develops in wheat and other small grains. If wheat borders your field corn, scout the wheat with a sweep net or look for stink bugs on the corn plants. When the wheat is cut, stink bugs will move to corn and could affect the developing ear and kernels. Thresholds for stink bugs in corn can be found here: https://entomology.ces.ncsu.edu/2018/04/new-stink-bug-thresholds-in-corn/. When plants are at V14 to VT, 21 to 26% of plants infested with stink bugs warrant a treatment. Thresholds are even higher for silk stage corn. These bugs will be located on the edge, and they will spend some time on the edge before moving into the field interior