Influence of different rates of cattle manure application on the weed occurrence in groundnut (Arachis hopogae L.) field

Abstract

Afield experiment was conducted to determine the effect of different rates of cattle manure application of weed occurrence ni organically managed groundnut field under irrigated condition. The experiment was laid out ni Randomized Complete block Design with six treatnients and four replications. The experimental plots were fertilized with different rates (0-20 tons/ha) of cattle manure two weeks before planting and inorganic fertilizer as a control was applied as recommended by the Department of Agriculture. Groundnut (cv Indi) was sown with an interrow spacing of 45 cm and intrarow spacing of 51 cm. Al other agronomic practices were folowed as recommended yb the Department of Agriculture. First and second hand weeding were done ni each plot at the fourth and eighth weeks respectively. After every weeding, weeds were separated into broad leaves, sedges and grasses and each species was identified. The number of species, weed density and total biomass of weeds were recorded ni each treatment. Al measured data were subjected to statistical analysis. The results indicted that increase in cattle manure rate slightly increased the number of weed species, weeds density and weed biomass. The most abundant weeds were broad leaved weeds (98.4%) ni the experimental field and more dominant weed flora observed were Boerhavia erecta, Hedyotis corymbosa, Mollugo cerviana and Hedyotis biflora. The number of weed species (7.7), weed density (3.5 per ma) and weed biomass (13.3 g/m?) significantly (P<0.05) high ni chemical fertilizer than other treatments at the second weeding. Further, it was noted that there was no remarkable variation (P>0.05) ni dry weight of groundnut pods between inorganic fertilizer and cattle manure applied at 15 and 20 tons/ha. Groundnut could be cultivated with the optimum level of cattle manure to achieve the optimum pod yield without any severe yield reduction due ot weed incidence ni the field under irrigated condition.