With a warmer than normal winter, spring may come early to many Missouri farm fields bringing with it weeds. Typically, giant ragweed is one of the first to emerge in April. Once this weed arrives, other generally follow suit. And if the warm weather of 2012 persists into 2013, they may arrive earlier.
Knowing what weeds to plan for is crucial to creating a control plan. Kevin Bradley, University of Missouri Extension weed specialist outlined the top 10 weeds to watch for this year at the MU Crop Management Conference.
Researchers combed more than 130 locations across much of northern Missouri, from along Highway 50 in the central portion of the state and north, to the western side of the state. They wanted to document just what weeds were popping up in fields. They looked at fields that had been in a soybean-corn rotation, corn-soybean rotation and soybean-soybean rotation. And they saw two common weeds popping up in both corn and soybean fields.
The problem with control of palmer amaranth is its resemblance to waterhemp. Oftentimes it can go misidentified by farmers and crop advisors.
"There was no surprise," Bradley said. "Waterhemp was number one and morningglory was number two."
Both weeds showed up heavily in soybean and corn fields. Waterhemp was seen 51% of the time in corn fields surveyed and 80% in soybean fields. "We still have a problem with waterhemp in the state," Bradley added. "There is no denying it."
Morningglory was most prevalent in corn fields at 45%, and 33% in soybean fields.