EFFECT OF CROP SPECIES, TILLAGE, AND RYE (SECALE-CEREALE) MULCH ON SICKLEPOD (SENNA-OBTUSIFOLIA)

Field studies were conducted to determine the effect of crop species, tillage, and rye mulch on sicklepod growth. Competition from soybean a nd sunflower reduced sicklepod biomass by 19 and 77%, respectively. Si cklepod height was reduced by rye mulch. Rye root residue caused 49% r eduction in sicklepod biomass, while whole plant rye mulch reduced wee d growth an additional 12%. Crop competition reduced sicklepod shoot b iomass to a greater extent when rye residue was present. Crop seed yie ld was 32% lower in tilled plots compared with no-tillage due to more weed competition in the tilled plots. In the presence of rye root resi due, soybean yield showed a two-fold increase over no mulch or whole p lant rye mulch. Sunflower yield increased by 30% in the presence of ry e residue compared with no mulch.