Alellopathyc potential of vegetable extracts ofCrotalaria junceaon germination of weed

Abstract

The objective of this study was to evaluate the effec of vegetable extracts Crotalaria juncea cultivated under different spacing and plants densities on the germination of weed (Ipomoea grandifolia (Dammer),Bidens pilosa L. and Euphorbia heterophilla L.). The study consisted in 2 phases: phase 1st stage planting of Crotalaria juncea L. to obtain material for the extraction of volatile allelochemical; 2nd stage preparation for extracts and performace of bioassays. The experimental design was randomized complete in a fotorial 4x3 (where 4 different concentrations of extracts (25, 50, 75, 100%), come from cultivation of Crotalaria juncea L. under spacing (25 cm) and 3 different densities of plant (25, 40 and 50 plants per linear meter)). Evaluations were made on the seventh day after sowing seeds. The data of germination and growth/development were submitted to analysis of variance of 5% level, and grouping by Skott-nott. The results indicated that in the concentration of the extract of Crotalaria juncea L. promoted increased in number of seeds of black Bidens pilosa L. and Euphorbia heterophilla L., but reduce the germination of Ipomoea grandifolia (Dammer).