EFFECT OF MICRONUTRIENTS (B AND Zn) AND SOWING TIME ON WATER RELATIONS AND YIELD OF MUNGBEAN

Abstract

A field experiment was conducted at the Sher-e-Bangla Agricultural University Farm, Dhaka, in the Kharif-II season during the period from August 2013 to January 2014 to study the effect of micronutrients (B and Zn) and sowing time on water relations and yield of mungbaen (Vigna radiata L.).The experiment consisted of five levels of micronutrients viz., F0 = Recommended Fertilizer Dose (RFD) [ 20.7 kg N/ ha, 48 kg P2O5/ha and 34.8 kg K2O/ha]; F1 = RFD + 1 kg B/ha; F2=RFD +2 kg B/ha; F3= RFD +8.5 kg Zn/ha; F4 = RFD + 17 kg Zn/ha and three sowing time, viz., (S1= 24 August, S2=23 September and S3=23 October). The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. The results indicated that increasing micronutrient level reduced number of days to 1st emergence, 80% emergence, 50% flowering and increased exudation rate, relative water content, number of branches plant-1, number of pods plant-1, pod length, number of seeds pod-1, 1000-seed weight, seed yield and harvest index except B @ 2 kg/ha for exudation rate. Delayed sowing from 24th August to 23th October reversed the effects for all the parameters mentioned above except days to 50% flowering. Highest exudation rate (2352 mg hr-1), relative water content (93.33%), number of branches plant-1(3.00), number of pods plant-1 (17.67), longest pod length (10.60 cm) and number of seeds pod-1 (11.67), 1000-seed weight (42.83 g), seed yield (1.85 t ha-1) and harvest index (64.24%) were found when mungbean was sown on 24th August and applied recommended NPK with 17 kg Zn ha-1. On the other hand, lowest exudation rate (173.00 mg ha-1), relative water content (78.3%) and pod length (7.50 cm), number of branches plant-1 (0.33), pods plant-1 (7.00), number seeds pod-1 (7.50), 1000-seed weight (28.25 g), seed yield (0.51 t ha-1) and harvest index (12.09%) were found when mungbean was sown on 23 October and applied recommended fertilizer dose(F0). It was also observed that recommended NPK with 17 kg Zn ha-1 gave the highest performance for all the parameters mentioned above under all the three sowing conditions.