Weed management in sunflower using cover crops

In order to evaluate alternative strategies for weed management in sunflower using cover crops, an experiment was carried out as a factorial based on a randomized completely block design with three replications. Factors were cover crop type at three levels (hairy vetch, pearl millet and buckwheat) and cover crop density at four levels (0, 33, 66 and 100% of recommended density for each crop in monoculture). Hand weeding was also considered as control. Results showed that all three cover crops had significant effect on the weeds and the weed biomass severely decreased due to suppression by cover crops. There was also a negative correlation between cover crop density and weed biomass. Planting buckwheat, hairy vetch and pearl millet resulted in up to 80, 86 and 91% decreases in weed biomass in comparison to no cover crop plots. However sunflower grain yield were reduce with increasing cover crop densities from 33 to 100% of recommended density of each cover crop in monoculture. Buckwheat at the density of 36 plant.m-2 significantly decreased the weed biomass and saved sunflower grain yield. In conclusion, planting buckwheat at the density of 36 plant.m-2 as a cover crop was recommended as a part of integrated weed management in sunflower farming because it was cost-effective and environment friendly than chemical weed control.