Timely herbicide applications are key for post-emergence control of marestail. Management is complicated due to some populations in Kansas with resistance to glyphosate and ALS-inhibiting herbicides. However, there are some options for control of large marestail.
With adequate moisture and high temperatures, Palmer amaranth populations are rapidly growing and causing concern for some sorghum producers in western Kansas. What options to growers have at this point in the growing season? Read more in the article from weed scientist Dr. Vipan Kumar.
Controlling marestail in soybeans continues to be a big challenge for Kansas no-till producers. Learn about early spring, pre-plant, and post-emergence options for treatment in this article from Extension Weed Science Specialist, Dr. Sarah Lancaster.
Pre-emergence herbicides are critical for successful weed management in grain sorghum, especially for difficult to control species like Palmer amaranth. When pre-emergence control efforts fail, learn the best options for Palmer amaranth in sorghum fields later in the growing season.
Challenging weather conditions in the spring may have resulted in rapidly growing Palmer amaranth in grain sorghum fields. Post-emergence herbicide options in grain sorghum are limited, with the available choices most effective when the weeds are small. This article discusses the pros and cons of key herbicides that can provide control.
Applying certain herbicides when air temperatures are high could reduce their effectiveness on controlling Palmer amaranth. Research conducted at K-State described two key changes about how Palmer amaranth responds to applications of mesotrione (Callisto) under high temperatures.