Corn ear abnormalities have been noted the past few years. Tracing back the information on various field calls often pointed to a misunderstanding of proper growth stages when making post-emergence herbicide applications in addition to pre-tassel fungicide and insecticide applications.
The past two weeks, we’ve received a number of calls regarding injured soybean plants during emergence. Additional questions include “What caused this?” and “Do I need to replant?” The following is what we’ve seen thus far.
Soybean planting was early this year in Nebraska, but dry soil conditions in most of May resulted in poor activation of pre-emergence herbicides applied in rain-fed fields and subsequently less than expected weed control.
After a frost, or hail event, the dead tissue is not able to resurrect itself and is eventually sloughed off as the plant continues to grow. Thus a common question is how do I determine corn growth stage when I can no longer count leaves?
Application of soil residual herbicides is important because they deliver a few weeks of residual weed control and aid in weed resistance management by incorporating additional site(s) of action in herbicide program. Several residual herbicides can be applied after corn emergence without injury to corn.
With the depressed corn and soybean prices in recent years in the United States, growers have shown interest in conventional soybean. Herbicide programs should be selected carefully that provide season-long weed control.
Soybean planting is about to start in Nebraska and it’s time to select pre-emergence herbicides to be applied in soybean. Protoporphyrinogen oxidase (PPO)-inhibiting herbicides are one of the key components of weed management in soybean.