Influence of intercropping and weed-control measures on dry-matter accumulation and nutrient uptake by sunflower (Helianthus annuus) and groundnut (Arachis hypogaea) and their effect on succeeding maize (Zea mays)

An experiment conducted during the spring seasons of 1996 and 1997 revealed that sunflower (Helianthus annuus L.) grown in 1:2 ratio of intercropping recorded significantly higher dry matter. However highest N and P uptake was recorded from. the sole crop. Intercropping suppressed the dry-matter accumulation and N and P uptake of groundnut. Weed-control measures enhanced the dry-matter accumulation of both sunflower and groundnut (Arachis hypogaea L.). Combined application of pendimethalin and 1 hand-weeding recorded the highest dry matter of both component crops. On an average, combined application of both weed-control measures showed 30.5 and 46.0% higher uptake of N and P by sunflower and 222 and 370% by groundnut respectively. Productivity and N uptake of maize (Zea mays L.) was significantly higher when it was preceded by intercropping of sunflower and groundnut. Weeds controlled by both pendimethalin and 1 hand-weeding also enhanced the productivity and N uptake by succeeding maize.