Black and white drawings. A tool for assisting grain inspectors in seed identification related to grain grading of small oilseeds crops. Text by Karen Bell. Illustrations by Norma Vidal. Edited by Steve Symons.
Previously published as: Handbook on Varietal Identification by Kernel Characters of Barley, Wheat and Small Oilseeds; Part III. by C.H. Owen and M.M. Ainslie: Minister of Agriculture, Canadian Grain Commission; Ottawa, Canada; 1971.
Users should be aware that weed seeds discussed in the bulletin represent a very small number of species of weed seeds that could potentially occur in oilseeds crops. The weed seeds discussed in this bulletin were selected based on being problematic in grain cleaning, end product quality or similarities in visual seed identification to oilseeds crops or other weed seeds of concern.
But not at every harvest. Because whatever specific iteration of harvest weed-seed control Colorado growers may eventually adopt, it should be just one element of an integrated management strategy, Soni cautioned.
Known as harvest weed-seed control, these IPM-friendly methods are designed to destroy or remove weed seeds during harvest to prevent them from raining down onto the soil and replenishing the weed seed bank. In Colorado wheat, weed species of concern are winter annual grasses that share the grain’s growing cycle, like jointed goatgrass, feral rye and downy brome.
“What we found is that the majority of seeds are still retained at harvest,” Soni said. “Downy brome is the same height as wheat, rye is taller and jointed goatgrass a little shorter, but growers could adjust their cut height to manage it.”
Targeting Weed Seeds at Harvest
Not every grower would need to buy one.
In short, it should be part of an IPM program.
So the Weed Research Lab team measured and counted a lot of weeds.
Soni then counted out 1,000 seeds of each weed species into a specified amount of chaff and drove to the University of Arkansas where they have a seed destructor set up on a test platform. She ran each bundle through the destructor. The pulverized material was dusted across beds of soil to see if any weed seeds germinated. Virtually none did.