Weed Composition and Diversity as Influenced by Non Chemical Weed Management Practices in Sunflower

Field experiment to study the influence of non chemical weed management practices on weed composition and weed species diversity was carried outat Tamil Nadu Agriculture University, Coimbatore. Twelve non chemical treatments with physical/mechanical and cultural principles of weed management practices were included. Experiment was laid out in randomized block design with three replications. Unweeded control treatment weed flora comprised dominance of grassy weeds (64.29%) followed by broadleaved weeds (19.48%) and sedges (16.23%). Variation in relative density of the weeds was recorded under the influence of non chemical weedmanagement practices. Physical methods of non chemical weed management proved better than cultural methods in management of weeds. Stale seedbed and allelopathic treatment, spray of eucalyptus oil at 0.4 per cent at 3 DAS did not exhibit any significant effect as indicated by higher absolute density of weeds. In situ green manuring with sunhemp at 45 DAS and intercropping with coriander reduced the sedges population at 45 DAS and at harvest. Highest grassy weeds density was observed in unweeded control at 25, 45 DAS and at harvest.