Weed Resistance

One of the problems with a wet start to the season when planting gets compressed into short periods is the lack of time to apply preemergence herbicides and 28% before corn emerges. Most pre-emergence corn herbicides can be applied to emerged corn, and some of them have enough foliar activity to control small, emerged weeds without the need to add postemergence (post) herbicides....More

Wet soil conditions have caused delays in planting and in efforts to control existing weed vegetation. Much of the existing weed growth is comprised of winter annual species, such as common chickweed, henbit, purple deadnettle, etc., but emergence of several summer annual species also has begun....More

Dry soil conditions, such as such as those in Illinois in 2012, often slow the rate of herbicide degradation and increase the potential for damage to rotational crops from herbicide carryover, according to Aaron Hager, a University of Illinois weed science expert....More

As if last year's drought didn't cause enough problems in 2012, now there are some agronomic factors that could impact the 2013 crop if producers don't manage them appropriately. Those factors include potential herbicide carryover and heavy weed pressure in existing crop stands....More

Two Purdue Extension specialists have developed an information guide to help crop producers across Indiana deal with Palmer amaranth, an aggressive, herbicide-resistant weed. Weed scientists Bill Johnson and Travis Legleiter released a new publication, Palmer Amaranth Biology, Identification and Management in Indiana (pdf), to help farmers control the weed's spread....More