EFFECTS OF GREEN FOXTAIL AND LAMB’S-QUARTERS INTERFERENCE IN FIELD CORN

Abstract

Field experiments were conducted to study the effects of full season interference of various densities of green foxtail (Setaria viridis (L) Beauv.) and lamb’s-quarters (Chenopodium album L.) on the yield of field corn. Green foxtail interference was studied at densities of 0, 29, 56, 89 and 129 plants/m2 in 1976 and 0, 20, 40, 62, 84 and 119 plants/m2 in 1977. Non-significant (P = 0.05) corn yield reductions were obtained at densities of 56 and 20 plants/m2 in 1976 and 1977, respectively. Increased green foxtail density reduced corn yields by 5.8–17.6% in 1976 and 5.6–16% in 1977. Lamb’s-quarters interference was tested at densities of 0, 46, 83, 112, 167 and 221 plants/m2 in 1976 and 0, 54, 109, 172, 208 and 277 plants/m2 in 1977. Corn yields were not reduced significantly at lamb’s-quarters densities of 46 and 109 plants/m2 in 1976 and 1977, respectively, compared to weed-free treatments. Yield reductions\ranged from 12.3–37.9% in 1976 and 6–58% in 1977. The competitive effects of green foxtail and lamb’s-quarters on corn yield differed mainly on the ability of the latter to reduce ear and seed size.