|CRAWFORD, LAURA - University Of Illinois|
Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2018
Publication Date: 8/29/2018
Citation: Crawford, L., Williams, M.M. II. 2018. Role of edamame (Glycine max) seed size in early-season crop-weed interactions. Weed Science. 66:746-751. https://doi.org/10.1017/wsc.2018.46.
Interpretive Summary: Crops with enhanced weed competitiveness have been heralded as one approach to improving weed management at a time when weeds are becoming more difficult to control. However, documented examples are rare. This research showed that one way to improve the crop’s ability to limit weed growth involves using aggressively growing cultivars of edamame, a nutraceutical food-grade soybean now produced in the U.S. In addition, planting the largest seed of these cultivars resulted in plants that were least affected by neighboring weeds. The impact of this research is providing an additional, non-chemical tool that could relatively easily be integrated into weed management systems for edamame.
Technical Abstract: Edamame (Glycine max (L.) Merr.) differs from grain-type soybean in several aspects, including that edamame seed are 65 to 100% larger than grain-type soybean seed. Crop seed size has implications for weed management in grain-type soybean; however, the extent to which this observation holds true for edamame is unknown. Since weed interference continues to be a problem in domestic edamame production, the objective was to quantify the effect of edamame seed size on the crop’s ability to tolerate weed interference (CT) and the crop’s ability to suppress the weed (WSA). Seed of five edamame cultivars plus one grain-type cultivar were sorted and separated into ‘small’ and ‘large’ seed size classes. Seed lots were included in a split-split plot design, whereby an additional experimental factor was presence or absence of velvetleaf (Abutilon theophrasti Medik.). Crop and weed emergence and growth were monitored through eight weeks after emergence (WAE). Crop plants from large seed had higher tolerance to A. theophrasti than plants from small seed as evidenced by crop height, crop area, and crop biomass. Edamame seed size had little effect on WSA; however, crop cultivars differentially reduced A. theophrasti leaf area and A. theophrasti biomass at four and eight WAE. While both seed size and edamame cultivar influence crop competitive ability, the magnitude of these factors on CT and WSA underscores the importance of considering them not as stand-alone tactics but rather as useful additions to a more comprehensive integrated weed management system.