Treating Weeds with Herbicides under Drought Conditions

Weed management is highly impacted by high temperatures combined with low and variable precipitation. Hot weather and drought affect the germination, growth, hardiness and competitive ability of both desirable plants and weeds. Many weeds, once established, need very little water to survive.

Perennial weed species such as spotted knapweed, field bindweed and Canada thistle have extensive, deep root systems and are able to “mine” water. Perennial weeds and other plants also have the ability to establish a dormant state for some time during water and heat stress and can then resume growth during...