Impact of weather variables on dry matter accumulation and yield of mungbean [Vigna radiata (L.) Wilczek] varieties under different dates of sowing

A two year experiment was conducted at the BCKV with four mungbean varieties (Pant Mung-5, Bireswar, RMG-62 and Sukumar) sown under three dates (15^th February, 1^st and 15^th March) in a split plot design where dates of sowing and varieties were allotted to main and sub plot treatments respectively with three replications. PAR was recorded with the help of line quantum sensor. Dry matter accumulation, yield attributes and yield were measured. Canonical correlation and correspondence analysis showed that absorbed PAR during 32 to 46 days after emergence (DAE) increased dry matter, pod and seed yield. PAR use efficiency (PARUE) of mungbean ranged from 0.75 to 0.88 g MJ⁻¹ for seed yield. PARUE for dry matter production was maximum during 39 to 46 DAE. According to PARUE and heat use efficiency, Pant Mung-5 should be sown within 1^st March in this zone. Growing degree day requirement gradually increased with delayed sowing.