A field experiment was conducted at the Agricultural Research Station, BARI, Rajbari, Dinajpur during the kharif-1 season of 2016-17 and 2017-18. The aim of the study was to determine the optimum sowing date for maximizing the yield of mungbean in Dinajpur area of Bangladesh. The test crop for the experiment was BARI Mung-6, which was sown on five different dates viz., 25 February (S1), 05 March (S2), 15 March (S3), 25 March (S4) and 05 April (S5). Days to flowering and maturity were different for different sowing time. It was found that sowing performed on 05 March produced the highest seed yield including the highest number of pod length, pods plant-1, seeds pod-1 and 1000-seed weight. Mungbean sown after 05 March gradually decreased the seed production and it was sustained upto 05 April. It exposed that sowing should preferably be done around 15 March and sowing is not desirable beyond 25 March at all under agro-climatic conditions of Dinajpur areas of Bangladesh.
Key words: BARI Mung-6, sowing time, growth, yield
Mungbean (Vigna radiata L.) is one of the important pulse crops, which contains high quality vegetable protein and satisfactory amounts of minerals and vitamins. Due to easy digestibility, better palatability and high market price, mungbean is the first choice to the farmers. The agro-ecological condition of Bangladesh is favorable for growing mungbean in the winter season although it is cultivated in both summer and winter seasons in many countries of the world (Bose, 1982 and BARI, 1998). Recently, farmers are not much interested in growing pulse crops in winter season. Besides these, increasing area under wheat, maize and irrigated boro rice cultivation has further reduced the area under pulses. Therefore, it has become imperative to shift the cultivation of some of the low yielding pulses from winter to summer seasons. The possibility of growing mungbean in the summer season in Bangladesh is tried with some success (FAO, 1984). A good number of high yielding mungbean varieties are available now in Bangladesh but, farmers generally grow the local varieties using almost no fertilizer and they rarely maintain the proper sowing time. Moreover, farmers are losing interest in producing mungbean due to low income per unit of resources invested. Therefore, attention should be given to increasing yield through selection of suitable varieties and adoption of improved cultural practices for establishing mungbean as a profitable crop. For any yield improvement programme selection of superior parents is a prerequisite i.e., possessing better heritability and genetic advance for various traits (Ahmad et al., 2008). Sowing time, a non-monetary input, is the single most important factor to obtain optimum yield from mungbean (Samanta et al., 1999). So determination of optimum sowing time for mungbean is inevitable. Optimum time of sowing of mungbean may vary from variety to variety and season to season due to variation in agro-ecological conditions. Therefore, there must be a specific sowing dates, especially in the summer season for different varieties to obtain maximum yield. Delayed sowing after March and early sowing before February reduce yield of summer mungbean (Chovatia et al., 1993). February may be considered as the optimum time for summer mungbean and late planting after March may subject to rain damage during maturity period (Dharmalingam and Basu, 1993). The present investigation was therefore, undertaken to identify the suitable sowing time of mungbean for the Dinajpur area of Bangladesh.