Effect of Component Densities on the Performance of Pearl millet - Mung bean Intercropping System Under Different Rainfall Situations in an Arid Environment

Abstract

A field study on pearl millet and mung bean component densities in intercropping was assessed under three cropping season rainfall situations, viz .. above normal (409 mm), normal (301 mm) and below normal (190 mm) having 24, 14 and 8 effective rainy days. respectively. The soil was sandy loam having 10.5 and 2.5% moisture content (w/w) at field capacity and -IS bar tensions, respectively. Decreasing the density of pearl millet (principal crop) from 20 to 13.3 plants m'2 increased its yield, but further decrease to 10 plants m'2 decre~sed the yield at all levels of intercrop component densities irrespective of the type of season. The yield of component crops depended more on the effective stmage of moisture in the soil profile and availability of moisture at reproductive stage (weeks 8-12) rather than quantum of rainfall during the season. Component density combination of 13.3 plants m,2 of pearl millet with 5 plants m'2 of mung bean was optimum and resulted in the highest grain yield. LER and WUE in all seasons. Moisture stress in below normal season and the availability of radiation in lower half of the canopy in good rainfall situation was a limiting factor for pearl millet yield. Higher consumptive use (214-254 mm) was recorded in moisture stress free seasons compared to below normal rainfall season (150-157 mm). On an average, harvest index was lower (0.24) in moisture stress season (due to differential influence of terminal drought on grain and total dry matter yield) as compared to normal and above normal rainfall seasons (0.42). High sustainable yield index for pearl millet under optimum component density (0.37) compared to sole cropping (0.23) indicated better stability of pearl millet production due to intercropping in arid environment.