Variable weather makes weeds harder to whack

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. It also means common pre-emergence herbicides are less effective.

source https://www.sciencedaily.com/releases/2021/02/210208173051.htm