Influence of Non Chemical Weed Management Practices on Nutrient Uptake in Sunflower and Weeds

Field experiment to study nutrient uptake by crops and weeds as influenced by non chemical weed management in sunflower was conducted at Tamil Nadu Agriculture University, Coimbatore. Treatments comprised of physical, mechanical and cultural weed management practices. Results indicated higher nutrient uptake (81.0, 11.7 and 47.4 kg N P₂O₅ K₂O ha⁻¹) in crops in the treatment which was subjected to twice hand weeding at 25 and 45 DAS. Manually operated weeder at 25 DAS followed by hand weeding at 45 DAS (73.2, 10.7 and 43.5 kg N P₂O₅ K₂O ha⁻¹) was next best treatment. Higher nutrient drain by weeds was recorded in weedy check (44.2, 8.1, 37.3 kg N P₂O₅ K₂O ha⁻¹) followed by eucalyptus oil spray at 0.4 per cent sprayed 3 DAS (28.3, 6.3 and 30.5 kg N P₂O₅ K₂O ha⁻¹). Positive response of crop yield to nutrient uptake and negative response to weed nutrient drain was observed. Hand weeding twice and manually operated weeder + hand weeding recorded significantly higher sunflower yield on account of higher crop nutrient uptake and corresponding lower weed nutrient drain. Effective management ofthe weed well within the critical crop weed competition period resulted in curtailing the weed competition and promoting the growth and yield of the sunflower.