Effect of tillage and weed management practices on weed growth and productivity of maize-greengram cropping sequence

A field experiment was conducted during rabi 2017-18 and summer 2018 at farmer’s field of Muluk village, Birbhum, West Bengal to evaluate the effect of tillage and weed management practices on weed growth and yield of rabi maize and greengram. Maize hybrid DKC 9081 and Samrat (PDM 139) variety of greengram were taken in the experiment. Four tillage practices viz, conventional tillage (CT) in maize - CT in greengram, CT (Maize) - Zero tillage (ZT) (greengram), ZT (maize) - CT (greengram) and ZT (maize) - ZT (greengram), and three weed management practices viz. recommended herbicide (atrazine at 0.625 kg ha^-1 in maize and pendimethalin at 0.75 kg ha^-1 in greengram), herbicide combination (tembotrione at 90 g ha^-1 + atrazine at 500 g ha^-1 at 20 DAS in maize and pendimethalin at 0.75 kg ha^-1 followed by imazethapyr at 75 g ha^-1 in greengram at 20 DAS) and unweeded control were allocated in a strip-plot design replicated thrice. Rabi maize was infested with six weed species viz. Cynodon dactylon, Digitaria sanguinalis, Croton bonplandianum, Polygonum plebeium and Grangea maderaspatana and Cyperus iria whereas C. dactylon, Echinochloa colona, Murdania nudiflora, Fimbristylis miliacea and C. rotundus were present in greengram. Zero tillage (ZT) based practices were observed to have higher weed pressure compared to conventional tillage (CT) based practices both in maize and greengram. Conventional tillage registered significantly lower total weed density (17.66 m^{-2 -} in CT-CT and 17.76m^-2 in CT-ZT) than ZT based practices (24.93 m^-2 in ZT-CT and 24.60 m^-2 in ZT-ZT). CT-CT also registered significantly the lowest total weed biomass (11.07 g m^-2) at 45 DAS. In greengram also, CT-based systems recorded significantly lower total weed density and dry weight than ZT-based systems. In maize, herbicide combination recorded significantly higher yield (9062 kg ha^-1) than that of recommended herbicide (8202 kg ha^-1) and weedy check (6259 kg ha^-1), while tillage practices did not differ significantly. CT-CT produced the highest yield (1034 kg ha^-1) of greengram, whereas ZT-ZT recorded significantly the lowest (761 kg ha^-1). Herbicide combination (1128 kg ha^-1) and recommended herbicide (1058 kg ha^-1) both were at par and outperformed the weedy check (584 kg ha^-1) regarding seed yield of greengram.