NDSU Crop and Pest Report - May 16, 2013
Temperature, Herbicide and Crop Response (6/7/12)
Many people are asking how long should herbicide applications be delayed after frost damage to crops. Cold weather is a stress to plants.
Desiccation from frost is a stress. Any stress can inhibit a plant’s ability to degrade and metabolize pesticides. Preferably, herbicide applications should be delayed until new plant growth appears and a sign that plants have resumed normal growth. Unfortunately, weeds will continue to grow and may be larger than desired. So it is a judgment call as to how soon the herbicide can be applied, but wait at least a couple of days. Warmer daytime temperatures can also speed recovery of crop plants.
Rich Zollinger
Extension Weed Specialist
