Just like the weeds they target, herbicides are also sensitive to the weather—before, during, and after application. Now, with the aid of computer modeling and one of the largest databases yet, a team of scientists is working to refine the outlook for herbicide use in corn and soybean crops amid extreme weather events. The resulting data, in turn, will help inform farmers decisions on where, when, and how best to apply the chemicals and safeguard crop yields.
Led by Christopher Landau, a postdoctoral research agronomist with the Agricultural Research Service (ARS) in Urbana, Il, the computer models leverage historical data gleaned from more than 10,000 herbicide evaluation trials conducted by land-grant universities across the United States.
Weeds outrank insects and disease as top threats to corn and soybean crops nationwide, inflicting yield losses of up to 50% if left unchecked. Post-emergent (POST) herbicides, which target above-ground weeds, constitute a major portion of the total herbicides applied to corn and soybeans, which supply the lion’s share of America’s grain and edible oil, respectively.
However, mindful of shifts in seasonal rainfall patterns and temperature, the scientists set out to better understand the portent of those shifts on herbicide effectiveness for the weeds they target.