The heavy rains across the state have made timely post-emergence weed control difficult, even in fields treated with pre-emergence herbicides.

This leads to questions as to what can be done to ensure control of weeds larger than specified on herbicide labels.

Managing large waterhemp in soybeans is a particular challenge, but many of the principles are the same with other weeds.

Resistant species

The occurrence of waterhemp resistant to Group 2 (ALS inhibitors) and Group 9 (glyphosate) herbicides greatly complicates...