Effects of intercropping and plant density on growth, development and yield of pigeonpeas (cajanus Cajun cl.) millsp. and maize (zea mays L.). under semiarid conditions of Kenya

Abstract

In semi-arid areas of Kenya 95% and 7U% of pigeonpeas and maize, respectively are intercropped annually. This study was designed to determine the effects of intercropping pigeonpeas and maize at variable plant densities and also to determine the appropriate intercropping ratio or combination for optimum economic yield. Two pigeoopea cultivars were intercropped with Katumani maize at three plant densities in Kabete, Thika and Kiboko during the 1986/87 cropping season. The experimental design was a split-split plot with three replications at each location. Results indicated that intercropping and plant density reduced leaf area and shoot dry weight of both pigeonpeas and maize. Plant height of pigeonpeas was reduced by intercropping while that of maize was increased. In pigeonpeas number of mature pods and grain yield per plant were reduced by both intercropping and high plant density. Reduction in 100 seed weight varied with location suggesting an environmental influence. For maize, number of cobs and grain yield per plant were also reduced by intercropping and high plant density. , (xxiv) Generally, yield per hectare of a species in' intercrop was lower than in monocrop, but total yield of intercrops (pigeonpea + maize) gave higher yield advantage over monocrops. Land equivalent ratio (LER) values indicated that all intercrop ratios were superior to monocropping. At all the experimental sites best intercrop combination was attained when a row of pigeonpea alternated with a row of maize. Each crop at an interrow spacing of 105 cm.