That is the question many producers are dealing with across Central and Western Montana. A dry spring has led to delayed emergence of weeds in winter wheat. Weeds that have emerged are potentially drought stressed making management with herbicides difficult. In addition, decreased yield potentials dramatically impact the bottom line leading to questions about whether or not costs for herbicides are justified.
Drought stress leads to thicker cuticles and a reduction or shut down in weed growth.
As a result, it is more difficult for herbicides to penetrate into the plant. If they do get inside, it is hard for them to move to growing points and inhibition of enzyme systems to occur. As a result, overall herbicide effectiveness is reduced. Many grain fields in Central Montana face limited yield potential due to dry soils. On fallow ground, there is anywhere from 20 to 30 inches of moist soil which is barely enough to ensure seed head formation.