GROWTH, LIGHT INTERCEPTION, RADIATION USE EFFICIENCY AND PRODUCTIVITY OF MUNGBEAN [VIGNA RADIATA (L.) WILCZEK] (FABACEAE) CULTIVARS AS INFLUENCED BY SOWING DATE

Abstract

The purpose of this study was to assess the influence of sowing date on growth, light interception, radiation use efficiency and productivity of mungbean cultivars. The experiment comprised four sowing dates at ten days interval, viz. 08, 18, 28 July and 07 August 2006 and two
cultivars, viz. Gofa local and MH-97-6. A randomized complete block design with three replications was used. Early sown plants on 8 th of July had
extended duration to attain physiological maturity, larger leaf area index (LAI) and greater dry matter accumulation. Moreover, early sown plants
exceeded in amount of light interception, radiation use efficiency (RUE) and grain yield compared to the late sown ones. The RUE values were 1.74, 1.38, 1.28 and 1.10 g DM MJ -1 for the first, second, third and fourth sowing dates, respectively. The decline in yield of last sown mungbean compared to first sowing was about 2% per day of delayed sowing. Cultivar MH-97-6 exceeded Gofa local in LAI and total dry matter. However, their differences in cumulative intercepted PAR, RUE and grain yield were not statistically significant. Grain yield was significantly correlated with growth period moisture (r=0.95), cumulative intercepted light (r=0.98), RUE (r=0.96) and LAI (r=0.82). Early July sowing gave superior performance among tested sowing dates of the main cropping season (meher). However, owing to the crop’s short growth duration, it is worthwhile to do further research by including other sowing dates of the short rainy season (belg).