14 July 2022, Colorado: An article featured in the latest edition of the journal Weed Technology shows that electrocution can be an effective way to control weeds commonly found in soybean crops.
The authors describe two field studies conducted using a tractor attachment called The Weed Zapper™, which is designed to kill weeds using electricity.
In the first study, the team explored the effectiveness of electrocution on waterhemp, cocklebur, giant and common ragweed, horseweed, giant and yellow foxtail, and barnyardgrass. Electrocution treatments were applied at various heights and stages of growth. Control was more effective in the later stages of weed growth and was most closely related to plant height and to the moisture in the plant at the time of electrocution. Once the weeds had set seed, electrocution treatments reduced their viability by 54 to 80 percent across the various species evaluated.
In the second study, researchers explored the effectiveness of electrocution on late-season waterhemp that escaped herbicide treatments. They found that electrocution controlled from 51 to 97 percent of herbicide-resistant waterhemp plants.
They also explored the impact of electrocution on soybean plants and their yield. At some stages of their growth, crops exhibited yield losses of 11 to 26 percent following electrocution treatments – though researchers say those results likely represent a worse-case scenario. In late-season treatments, for example, the clear height differential between waterhemp and the soybean canopy means that the electrocution device could treat waterhemp without sustained contact with the soybean crop.
“Overall, our results indicate that when electrocution is used as part of an integrated control program, it can eliminate late-season, herbicide-resistant weed escapes in soybean crops and reduce the number and viability of weed seeds that return to the soil seedbank,” says Haylee Schreier of the University of Missouri, a member of the research team.