Impact of planting density on wheat crop grown under different tree species in tarai agroforestry system of central himalaya, India

A field trial based Agroforestry system was established at Pantnagar during Rabi season 2012-13 for predicting the effect of spacing on growth and yield of wheat (Triticum aestivum L.) under Eucalyptus camaldulensis and Melia azedarach. The experiment was carried out in split-plot design consisting of two tree species in main plot, viz, Eucalyptus camaldulensis and Melia azedarch and four spacing treatments in sub-plot viz, 3.0m×1.0m, 3.0m×1.5m, 3.0m×2.0m and 3.0m×2.5m with three replications. The wheat crop variety“UP-2338” was sown on December 06, 2012 and harvested on April 27, 2013. Among the tree species, the maximum (15.1 q /ha) and significantly higher grain yield with 21.8% increment was recorded under Melia as compare to Eucalyptus. Whereas, among the different spacings, the wheat growth in terms of dry biomass at 120 DAS (495.4/m2 ), yield attributes and yield in terms of grain (16.0 q/ha), straw (29.4 q/ha) and biological yield (45.4 q/ha) under Melia was significantly higher at 3 × 2.5 m spacing as compared to other planting density. The correlation coefficient (r) studies exhibited that wheat growth and yield attributing characteristics shows significantly (p<0.05) high degree (r=0.75 to 1) positive correlation with each other. The investigation was done to find out the proper planting density for intercropping of wheat with tree species without comprising the wheat growth and enhancing its sustainability