EFFECT OF PLANT DENSITY AND TIME OF WEEDING ON THE PERFORMANCE OF MUNGBEAN (Vigna radiata L)

Abstract

An experiment was carried out to investigate the effect of plant density and time of weeding on the performance of mungbean cv. BAR! Mung-6 at the field laboratory of Sher-e-l3angla Agricultural University, I)haka-1 207.The experiment comprised three plant densities viz. 33 plants n1(D i ). 40 plants m 2 (13 2 ), 66 plants ni 2 (133) and four levels of weeding viz, no weeding (W 1 ), weeding at IS DAE (W 2 ), weeding at 30 DAE (W 3 ) and weeding at 45 DAE (W 4 ). The experiment was laid out in a randomized complete block design (factorial) with 3 replications. Results revealed that both plant density and time of weeding significantly influenced yield and yield contributing characters of mungbean. Among the 17 weed species identified during crop duration, Cyperus miundus (28%) was the most dominant both in weeded and unweeded plots. In the case of plant density, highest grain yield (899.2 kg ha 1 ) was recorded from 66 plants n1 2 density. Among the four levels of weeding the second level i.e. weeding at IS DAE performed the best in obtaining the highest values in almost all the parameters such as number of nodes plant -' (9.57). number of pods plant-1 (15.17), number of seeds pod 1 (11.08), plant height (60.81 cm), number of branches plant ' (3.73), weight of 1000- seed (29.80 g.) and seed yield (898.3 kg hi ').The highest yield (1220 kg ha 1 ) of mungbean was obtained from plots of 66 plants m 2 weeded at 15 DAE and the lowest yield (230.7 kghi') in plots of 33 plants m that remained unweeded. Delay in weeding decreased seed yield, yield attributes and dry biomass of mungbean but increased dry biomass of weed. The critical period of weed control appeared to be between 15 and 30 I)Al2. Unrestricted growth of weed reduced mungbean seed yield by 43-61%. Linear regression model indicated that for one kg hi' of weed growth, mungbean seed yield is reduced by one kg hi