Weed management in late sown wheat (Triticum aestivum) after rice (Oryza sativa) in rice-wheat system in rainfed lowland

To study the efficacy of different herbicides, tillage practices and weed control measures on late sown wheat (Triticum aestivum L. emend. Fiori & Paol) field experiments were conducted during winter of 2004–05 to 2006–07 at Ghaghraghat (Bahraich) in Uttar Pradesh. Significantly lower density, weight, and nutrient uptake by weeds was recorded with isoproturon + 2,4-D (0.75 + 0.6 kg/ha) resulting in higher mean grain yield (3.89 tonne/ha) and net income (Rs. 18,375/ha). Weed free treatment recorded the highest energy output and lowest energy use efficiency (EUE). Isoproturon + 2, 4-D resulted in the highest EUE and energy productivity followed by metribuzin. Conventional tillage (CT) significantly increased density and dry matter of weeds when compared with zero tillage (ZT), thus, ZT increased grain yield of wheat by 2.18% as compared to CT. Sulfosulfuron (25 g/ha) recorded the lower density and dry weight of weeds and higher weed suppression efficiency (83.43%) followed by isoproturon + 2,4-D (81.04%). Application of isoprturon + 2,4-D produced significantly higher grain yield in ZT, and sulfosulfuron in CT. Irrespective of tillage, isoproturon + 2,4-D gave the highest net income (Rs 17.12 x 10³/ha) and benefit: cost ratio (2.59). CT consumed 23.66% more energy than ZT. The EUE and energy productivity was highest with ZT and sulfosulfuron.