By Travis Legleiter and Bill Johnson
The combination of an early spring-planted crops, and drought, has lead to the earlier than normal maturity of corn and soybean crops. This along with some recent rains over the last month has lead to fields that contain green, actively growing weeds, from escapes or new emergence, in fields of mature crops.
Most of the time, late summer droughts, or a killing frost will dry down weed escapes prior to harvest. This year we will not have the luxury of waiting for a frost and many will need the assistance of herbicides to dry down weeds and allow for a timely harvest before crops begin to lodge.
Only a few products are available for use prior to harvest to aid in drying down green weeds. Harvest aid applications are to be made to mature crops only, not as an aid in desiccation of immature crops.
Many soybean fields are maturing unevenly and will make harvest aid applications and harvest in general a challenge this fall. Producers should also keep in mind that the majority of harvest aid products are contact herbicides and that selection of spray volumes and nozzles is crucial in acquiring adequate coverage.
Most labels recommend at least 10 gallons per acre for ground applications and a minimum of 5 GPA for aerial applications. Choose nozzles that allow for smaller droplets that will penetrate the canopy and cover vegetation, but also large enough to avoid drift issues.
The following table outlines the products labeled as harvest aids in corn and soybeans. As always refer to the herbicide label for further details of proper herbicide application prior to use.