Evaluation of wheat varieties under Populus deltoides plantation at various tree spacing

Abstract

An experiment was laid out during first fortnight of November, 2015 with sowing of six wheat varieties viz. PBW 677, PBW 725, HD 3086 as new and PBW 658, HD 2967, WH 1105 as prevalent under three spacing [8 × 2.5 m (S₁), 7 × 3 m (paired at 2.5 m; S₂) and 5 × 3 m (S₃)] of 4-year-old poplars. Tree growth was significantly better in S₁ spacing with diameter at breast height and height of 17.57 cm and 17.73 m, respectively. Photo synthetically active radiation (PAR) and yield attributes of wheat viz. tillers, spike length, 1000 grain weight and grains/spike and biological yield were maximum in S₁ spacing and minimum in S₂. Phenologically, HD 3086 was early to attain maturity under poplar while WH 1105 in open. On an average there was 28 per cent reduction in wheat grain yield under 4 year old poplar plantation as compared to that in open. Grain yield was significantly higher in S₁ (3.95 Mg ha^-1 ) than S₃ and S₂. Maximum grain yield was recorded in wheat variety PBW 725 (3.93 Mg ha^-1) which was statistically at par with PBW 677 (3.74 Mg ha^-1). Harvest index was maximum in variety HD 3086 (34.5%) under poplar where as in open it was maximum in WH 1105 (35%).The uptake of  N, P and K by wheat grain and straw was higher in open conditions than under the trees. The total N, P and K uptake was higher in wheat varieties PBW 725, WH 1105 and PBW 677, respectively.