Tillage can play an effective role in warming and preparing soil for planting.
When it comes to weed control, however, there are limitations and growers need to have a plan in place to tackle weeds that escape uprooting by cultivators, or those tenacious plants that manage to re-root and grow on to steal yield.
On this episode of RealAgriculture’s Corn School, we visit with BASF technical development manager Rob Miller at the company’s research site at Maryhill, Ont. Here Miller looks at a research trial to see how weeds have survived one fall cultivator pass and one spring cultivation — no herbicide has been applied.
Miller illustrates the contribution fall and spring cultivation can make to weed control. He notes that most tillage that took place during an open 2021 fall was conducted during warm and wet conditions that are not optimum for fall weed control. The second pass this spring demonstrates the hit and miss weed control growers see in the days and weeks after tillage. At this site, annual bluegrass, for example, was uprooted by tillage, “but it’s just sitting there and it’s going to re-root itself and continue to grow.
“Tillage can be successful at controlling some perennial weeds, but for some of these species it just covers them up and makes them more difficult to control,” adds Miller.
A weed like dandelion can create an iceberg effect, notes Miller. Tillage can cover most of the plant, while it grows vigorously underground with only a small portion of it visible above the soil. It’s also quite typical for dandelion tap roots that have been severed by tillage to re-establish and grow on.
Miller agrees that effective tillage can play an important role in weed control, but it is really part of an integrated weed management program. Whether it’s through burndown or soil-applied herbicides, growers “still need a plan in place to control some of these larger weeds and make sure to control them prior to the crop emerging,” he adds.
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