Evaluation of Different Weed Management Strategies in Clusterbean [Cyamopsis tetragonoloba (L.) Taub] under Rainfed Conditions of Punjab

Background: Generally, farmers cultivate clusterbean [Cyamopsis tetragonoloba (L.) Taub] on rainfed area but seldom adopt weed control practices in it. It becomes very difficult and uneconomical to maintain weed free environment throughout crop period in the field under rainfed conditions. Therefore, the current study was aimed to find an effective weed control practice in clusterbean under rainfed conditions. Methods: Effect of weed management practices of clusterbean with T1: Pendimethalin @ 1 litre/ha (PE), T2: Imazethapyr @ 0.1 kg/ha at 20 days (POE), T3: Stale bed technology, T4: One hand weeding at 20 DAS (days after sowing), T5: Two hand weedings at 20 and 40 DAS, T6: Imazethapyr @ 0.1 kg/ha at 20 days + hand weeding at 40 DAS, T7: Pendimethalin @ 1 litre/ha (PE) + hand weeding 35 DAS, T8: Pendimethalin @ 1 litre /ha (PE) + imazethapyr 0.1 kg/ha at 30 DAS and T9: Weedy check were investigated under rainfed conditions. Result: Weed control efficiencies of imazethapyr @ 0.1 kg/ha at 20 days + hand weeding at 40 DAS (T6), pendimethalin @ 1 litre/ha + hand weeding at 40 DAS (T7) and pendimethalin @ 1 litre/ha (PE) + imazethapyr @ 0.1 kg/ha at 20 days (PoE) (T8) were statistically similar. Imazethapyr @ 0.1 kg/ha at 20 days (PoE) + one hand weedings at 40 DAS recorded higher growth characters viz., plant height, dry matter and yield attributing characters viz., number of branches, number of pods/plant and seed index than other treatments. The highest seed yield was recorded in imazethapyr @ 0.1 kg/ha at 20 days (PoE) + one hand weedings at 40 DAS (422 kg/ha), being statistically at par with pendimethalin @ 1 litre/ha (PE) + one hand weedings at 40 DAS (390 kg/ha) and pendimethalin @ 1 litre/ha (PE) + imazethapyr @ 0.1 kg/ha at 20 days (PoE) (392 kg/ha) which was significantly higher than other treatments. Imazethapyr @ 0.1 kg/ha at 20 days (PoE) + one hand weedings at 40 DAS recorded 27.9 and 33.9 per cent higher seed yield than imazethapyr @ 0.1 kg/ha at 20 days (PoE) and one hand weedings at 40 DAS, respectively. The net returns and benefit-cost ratio were maximum for imazethapyr @ 0.1 kg/ha at 20 days (PoE) + hand weeding at 40 DAS (T6). It is inferred that imazethapyr @ 0.1 kg/ha at 20 days (PoE) + one hand weedings at 40 DAS was found the most effective and economic approach for weed control in clusterbean under rainfed conditions.