The aim of this study was to evaluate the allelopathic effects of the dry mass of plants of crabgrass (Digitaria horizontalis), incorporated into the soil at different densities, on the germination and early growth of corn, sunflower and triticale. The experiment was conducted in a greenhouse, and the plots consisted of a plant, in pots with a capacity of 2.5 L, arranged in a completely randomized design. Dry material of crabgrass in amounts equivalent to 0, 2.5, 5.0 and 10t ha-1 was incorporated into the soil. Emergence was checked daily until ten days after sowing, when the final percentage of emergence and emergence speed index were calculated. Plant height and dry weight were evaluated 35 days after sowing. Weed germination residue incorporation and emergence speed index were found to interfere in the species evaluated. Dry weight and plant height of all species were affected by the crop residues,decreasing according to the concentration of straw incorporated into soil, with the exception of triticale, whose height remained unchanged.
allelochemicals; germination; growth; crabgrass
