Different biomass quantities of the cover crops Arachis pintoi Krapov. & W.C. Gregory, Crotalaria juncea and Cajanus cajan were either incorporated or spread on the surface of the soil to study their effect on the emergence and dry mass production of the weeds Brachiaria decumbens, Panicum maximum and Bidens pilosa. The experiment was installed in pots and conducted under greenhouse conditions at the Department of Plant Production of ESALQ - Universidade de São Paulo, Piracicaba-SP, Brazil. The experimental design consisted of a 3 x 6 x 3 x 2 factorial. i.e. , three cover crops (A. pintoi, C. juncea and C. cajan), six amounts of cover crop mass, 0, 0.5, 1, 2, 4, and 8 times the average biomass produced under field conditions, three weeds (B. decumbens, P. maximum, B. pilosa) and two depths of cover crop residue incorporation (0 and 5 cm). The parameters evaluated were: two weed counting/pot, and weed dry mass yield (g/pot), at 15 and 30 days after the establishment of the experiment. Cover crop mass at the two depths of incorporation was shown to reduce the weed populations tested, although in different degrees of interference, with C. cajan being, in general, the most effective in suppressing weeds.
Arachis pintoi; Crotalaria juncea; Cajanus cajan; Brachiaria decumbens; Panicum maximum; Bidens pilosa
