Effect of Partial Shading on Yield and Yield Attributes of Wheat (Triticum aestivum L.) Intercropped with Dalbergia sissoo Roxb. Under Shallow Water Table Conditions

The experiment was conducted to see the effect of modified microclimatic conditions on the yield and yield attributes of wheat at G.B. Pant University of Agriculture and Technology, Pantnagar, during Rabi season 1996-97. Wheat cv. PBW-226 was intercropped with Dalbergia sissoo (Roxb.) (planted in March, 1989). There were fifteen treatments of the orientation of the tree rows; starting from North in anticlock wise direction. The angle between the two adjacent tree rows was 24°. Tree rows were pruned 0%, 30%, 45%, 60% and 90%, respectively, in anticlock wise direction. Total number of trees were 105. Area per tree was 30 m². Net radiation, yield and yield attributes were recorded below tree canopies and control. Net radiation available during grain filling and maturity stages ranged 70-75% and 58-77% of control during crop growing period. Grain yield and biological yield was found reduced below tree canopies and ranged 71.58-88.90% and 69.24-79.86% of control, respectively. Higher harvest index and yield attributes were observed in some of the treatments below tree canopies.