MOYEED HASAN TALUKDER
Major Professor: Dr. Moriah Bilenky
MS DEFENSE SEMINAR
July 10th @ 12:00 pm
HORT 222
“Evaluation of Ecological Weed Management Strategies for Edamame in the Midwestern USA”
Abstract: Edamame [Glycine max (L.) Merr.] is a specialty crop with untapped potential in the Midwest due to similarities in production practices to grain soybean and the potential for higher return per acre. Its high nutritional value and nitrogen-fixing capabilities can benefit crop rotation systems. In addition, there is demand for locally grown edamame in the US. Despite the benefits, there is limited research regarding the suitability of commercially available edamame varieties for this region. In addition, weed competition impedes edamame growth and challenges mechanical harvesting. Two studies were conducted to evaluate three ecological weed management strategies for Midwest edamame production: 1) selection of commercially available edamame varieties which are competitive with weeds, 2) timing of planting, and 3) row spacing.
Early emergence of edamame was evaluated under greenhouse conditions with and without weed competition at three different time points (before, on, and after edamame seeding). Early established weeds decreased edamame emergence by 22% and decreased edamame dry weight by 15% compared to later established weeds. Weeds’ competitive influence was significantly lessened when they were planted alongside or after edamame, regardless of variety. Later established weeds had 94% lower dry weight and 95% lower leaf area compared to early established weeds. Karikachi showed significant rapid emergence (79%) compared to Midori Giant (39%). Midori Giant produced the tallest plants (24.8 cm) and the greatest dry weight (3.79 g). There were no differences among varieties in weed-suppressing ability. Our preliminary results under greenhouse conditions suggest that early-season weed competition is necessary to obtain a competitive edge during edamame establishment.
Edamame growth and productivity were evaluated under field conditions along with three different row spacings: standard row spacing (30 inch) compared to two narrow row spacings (15 and 7 inch). Standard row spacing produced a significantly greater number of pods (27) per plant compared to 7 and 15-inch row spacing (9 and 16 pods per plant, respectively). 30-inch row spacing also resulted in the greatest marketable pod count (23) per plant compared to 7 and 15-inch row spacing (6 and 12 pods per plant, respectively). 7-inch row spacing reduced weed dry weight by 76% compared to 30-inch spacing. The greatest leaf area index (LAI) was measured at 7 inch row spacing and produced 40% higher LAI than 15 inch spacing and 75% higher LAI than 30 inch spacing. The dense
canopy (higher LAI) created more shade and competitive pressure against weeds. On average across all yield parameters, BeSweet 292 performed better compared to other varieties.
Our research concludes that timing of seeding and row spacing are potential ecological weed management strategies for edamame cultivation in the Midwest. Growers should give priority to weed control techniques that eradicate early-season weed competition. Such as choosing fast-emerging varieties, planting before summer annual weed emergence, or removing weeds before planting. However, further research is needed to understand the tradeoffs between yield and cost of weed management with weed suppression at narrow row spacing.