From flooded spring fields to summer hailstorms and drought, farmers are well aware the weather is changing.
From flooded spring fields to summer hailstorms and drought, farmers are well aware the weather is changing. It often means spring planting can’t happen on time or has to happen twice to make up for catastrophic losses of young seedlings.
According to a joint study between University of Illinois and USDA-ARS, it also means common pre-emergence herbicides are less effective. With less weed control at the beginning of the season, farmers are forced to rely more heavily on post-emergence herbicides or risk yield loss.
“We're having more variable precipitation, including conditions where folks aren't able to plant because fields are too wet. In those cases, pre-emergence herbicide applications are getting pushed back into a period that is consistently drier,” says Marty Williams, USDA-ARS ecologist, affiliate professor in the Department of Crop Sciences at Illinois, and corresponding author on the study.
Drier weather may be better for getting equipment onto the field for planting, but it’s a problem for pre-emergence herbicides. Using data spanning 25 years and 252 unique weather environments, Williams and his team found most pre-emergence herbicides needed 5 to 15 centimeters of rain within 15 days of application. If that didn’t happen, weed control rates plummeted.
Read more at University of Illinois College of Agricultural, Consumer and Environmental Sciences
Image: Variable weather can mean flooded fields in spring as well as reduced efficacy of pre-emergence herbicides, according to new research from the University of Illinois and USDA Agricultural Research Service. (Credit: Lauren D. Quinn, University of Illinois)
