The allelopathic potential of brassicaceae family weeds species on germination and early growth of barley, sunflower, clover and cotton

This study was conducted to evaluate the allelopathic effect of family Brassicaseae weed spices on germination and early growth of barley, sunflower, clover and cotton .Experiment design study was according to factorial and randomized complete in four replications. The first factor includes four species of plants (a1) clover, (a2) cotton, (a3) barley, (a4) sunflower and the second factor weed species at five levels (b1) heary cress, (b2) (lepidium vesicarium), (b3) kochia, (b4) stock, (b5) flixweld and the third factor concentration of residual weeds that levels (c0) 0 %, (c1) 5%, (c2) 10%, (c3) 20% concentration of the weed residue extract. Results showed that weed species had a significant effect on plant germination, so that kochia (Kochia scoporia) and stock (Mathiola Spp.) extract effect in reducing germination were highest and lowest, respectively. The crop of clover and barley, respectively, the lowest and highest average germination rate of 7.11 and 16.50 percent, respectively. The results showed that with increasing concentrations of weeds, crop germination decreased significantly. kochia (Kochia scoporia) extraction (20%) and the lowest percentage of germination of clover and much 3.54 percent, respectively. Finally, kochia weed control generally in agricultural crops in general and for the study of clover cultivation particularly is of utmost importance because their effect on the reducing germination and initial establishment.