Volume 57 Number 18 Date 08/16/2012
GIANT RAGWEED - Severe ragweed control problems are apparent in corn and soybean fields statewide following this season's record drought. The most advanced plants are now more than 10 feet tall. Historically, the distribution of giant ragweed was limited mostly to undisturbed habitats such as roadsides, fencerows and open areas, but it now commonly occurs among row crops. Earlier planting and reduced tillage practices are thought to be primary factors contributing to its spread, survival and adaptation to modern cropping systems. Also influencing its success are its innate competitive traits, including early emergence, staggered emergence times, a rapid growth rate and resistance to glyphosate-based herbicides. This "superweed" is expected to become even more common and abundant in the future, requiring growers to be more proactive in developing long-term ragweed management programs.
--Clarissa Hammond, DATCP Weed Scientist