A survey that ranks the commonest and troublesome weeds in 2020 was just lately accomplished by the Weed Science Society of America (WSSA).
Greater than 315 weed scientists from throughout the U.S. and Canada weighed in on seven classes of grass crops, masking weeds discovered in corn, rice, sorghum, turf, spring cereal grains, winter cereal grains, pastureland, rangeland, and different hay.
There have been some surprises, and a few outcomes from the survey that weren’t a shock, like Palmer amaranth being the most troublesome weed to manage in corn.
Lee Van Wychen, govt director of science coverage for Weed Science Society of America, based mostly out of Washington, D.C., just lately joined RealAg Radio host Shaun Haney, to speak about the survey’s outcomes.
Palmer amaranth was certainly one of the not-so-surprising hard-to-handle weeds that’s nonetheless prevalent throughout the survey space, particularly since there’s rising resistance to herbicides. Van Wychen says that out of the corn, sorghum, rice, and different cereal grain crops surveyed final yr, one would assume that eradicating a broadleaf weed for these crops could be simple.
“[It’s] sort of an eye-opener and kind of gives credit to how tough it is and it’s different growth characteristics — the root system and seed production, it’s photosynthetic use efficiency and nutrient use efficiency — it’s just a very awesome weed, to put it no other way,” says Van Wychen, including that producers received’t have the ability to spray their manner out of getting Palmer amaranth or its cousin, waterhemp.
Hearken to the full dialog, story continues under:
Bluegrass weed species are on the rise, the motive for which is tied to herbicide resistance. The final time the cereal crops had been surveyed, annual bluegrass was on the high 10 checklist, nevertheless it shot as much as quantity two in final yr’s outcomes.
“I believe there are ten different mechanisms that bluegrass is resistant to now, around the world,” says Van Wychen.
In relation to troublesome and commonest weeds for small cereal grains, foxtail species are on each lists. Wild oat is often up there on these lists in addition to frequent lamb’s-quarters, however foxtail makes the high of the lists.
Kochia in Western Canada is popping its head up in extra spots, says Van Wychen, and herbicide resistance is spreading quickly.
“If I had to regionalize some of the worst cropping system weeds, Palmer amaranth is clearly in the southern parts of the United States, and then waterhemp in the Midwest, and then kochia in the western states and provinces,” says Van Wychen. “So in those three the herbicide resistance is continuing to expand in both the number of active ingredients that it’s resistant to and the acreage that you see out there.”
Canada thistle tied for ninth place on the troublesome checklist and the commonest checklist, which isn’t one thing to rejoice.
So far as an built-in method to managing these weeds, Van Wychen says that cropping system continues to be the greatest weapon — the extra you may rotate, diversify, or change up the system, the higher.