Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2019
Publication Date: 4/23/2019
Citation: Williams, M.M. II, Moody, J.L., Hausman, N.E. 2019. Vegetable soybean tolerance to flumioxazin-based treatments for waterhemp control is similar to grain-type soybean. Weed Technology. 33:530-534. https://doi.org/10.1017/wet.2019.15.
Interpretive Summary: Edamame, also known as vegetable soybean, has increased in popularity among U.S. consumers. Formerly an entirely imported product, domestic vegetable processors are growing more edamame in recent years but lack cost-effective tools to control the waterhemp weed. This research found that several soil-active herbicides used to control waterhemp in grain-type soybean could be considered for use in edamame, because the crop was not injured by the herbicides yet waterhemp control was complete. The impact of this research is that it facilitates the registration of crop protection tools for an emerging specialty crop in the U.S.
Technical Abstract: The largest gap in current weed management systems of vegetable soybean (Glycine max (L.) Merr.) is believed to be waterhemp (Amaranthus tuberculatus (Moq.) J.D. Sauer). The objective of this research was to quantify vegetable soybean tolerance to preemergence herbicides for early-season A. tuberculatus control, including flumioxazin alone and in combination with chlorimuron, metribuzin, or pyroxasulfone at use rates labeled in grain-type soybean. Crop tolerance to the herbicides was tested in field trials with 20 vegetable soybean cultivars and four grain-type cultivars through four weeks after treatment (WAT). Flumioxazin-based treatments were equally safe, resulting in only minor crop response (<3% injury two WAT) and no effect on crop emergence or early season growth. All flumioxazin combinations provided excellent control of A. tuberculatus four WAT, as evidenced by reducing weed density from 29.7 plants m-2 in the untreated control to no A. tuberculatus in all combinations. Preemergence applications of flumioxazin alone or in combination with chlorimuron, metribuzin, or pyroxasulfone are as safe in vegetable type soybean as previously reported in grain-type soybean. Registration of these products in vegetable soybean would provide the industry with effective options for managing A. tuberculatus.