Adaptability of exotic and local accessions of mungbean (Vigna radiata (L.) Wilczek) to variation in sowing time in Bangladesh

Abstract Sixty exotic and local strains of Vigna radiata (L.) Wilczek were sown twice monthly throughout 1 year in central Bangladesh. “Summer” strains matured quickly, i.e. in about 40 days, only if sown in August–September, when the main crop is sown after jute and before wheat. The most extreme accessions in this group did not flower for at least 90 days when sown in December or January. “Modified summer” types, having either synchronous or asynchronous flowering and pod development, flowered 30–60 days after sowing at any time of the year. A smaller group of “winter” strains flowered within 3 months only if sown between August and March. Some high-yielding, early strains were identified for sowing in August–September, and others for sowing in April to replace the fallow phase now preceding autumn rice in the north-west (Barind) region. The results are discussed in relation to future introduction and breeding programmes.