A three-year research project produced some promising results controlling kochia by burying the pesky weed before it could mature into a tumbleweed and move long distances.
The work was led by Shaun Sharpe, an Agriculture Canada weed scientist in Saskatoon. Sharpe worked with six producers around Last Mountain Lake, about an hour north of Regina, from 2021-2023.
“The kochia seed is only viable for three years,” said Sharpe, “If we can pick out where it is and manage it heavily because these patches represent high densities of plant – that means we can apply a mulch or something to bury it. Kochia doesn’t tolerate burial, but we’re in an environment where we don’t want to use tillage for other reasons…so the idea here with patch management is I want to artificially bury it.”
Sharpe applied different materials to patches of kochia, such as black plastic, wheat chaff, and hydro mulch – a combination of seeds, mulch and fibre that’s used in erosion control. The researchers also mowed patches of kochia. The plastic had the best results, but was not the most practical. The chaff had the second-best results with higher levels of control in the first year of the study.
“The chaff treatment I’m very excited about this because chaff and straw are something that every grower is going to have if they’re producing wheat and other grains so it’s something that’s potentially on-farm that’s already at their disposal that we can either move around within field or between fields. The mulch didn’t hold up quite as well as I was hoping although it was still decent, and then the mowing is effective but it was taking three to five times per year.” Sharpe explained.
The chaff can introduce other weeds to the kochia patch but Sharpe believes the benefits outweigh the negatives.
“I your chaff unless you’re using a (weed) seed destructor, all the weeds that are in your field prior to harvest are now coming out in the chaff, so there’s always the potential for that,” he said. “If we’re going to seed something else that’s not kochia, that’s okay with me because you’re going to have additional competition in those patches from other weeds, just like if you’re doing a cover crop or something like that.”
As for herbicide use in kochia, Sharpe says use it on small plants and anything outside its range or label he doesn’t recommend. “Mow it and get it out of there,” Sharpe added.
Sharpe made his presentation earlier this month at the Saskatchewan Agronomy Update in Saskatoon. He is currently editing his research paper and hopes to have it published sometime next year.
(CJWW)
