Cooler and wetter than normal conditions have brought attention to the possibilities of increased herbicide damage in corn. Much of the corn planted in mid-April has emerged and started the process of metabolizing herbicides. Cool temperatures cause plant metabolism to slow, as well as slow herbicide degradation by the crop. Plant injury can occur when the right conditions exist. Symptoms of injury are highlighted below.
Photosystem II Inhibitors
Atrazine and metribuzin
Older leaves most affected
Photo courtesy of Purdue Extension
Bleached white leaves
Photo courtesy of Mike Cowbrough
(Ontario Ministry of Agriculture, Food and Rural Affairs)
Seedling Shoot Growth Inhibitor
Long-Chain Fatty Acid Inhibitors
Buggy whipped leaves
Poor seedling root & shoot growth
Photo courtesy of Missouri Extension
Crops will generally outgrow the injury as long as symptoms are not so extensive to kill the plant and yield is generally unaffected. Herbicide injury can mimic other deficiencies and symptoms. If you need help identifying a symptom, please contact us here at HarvestMax and we would be happy to help in any way that we can.