Assessment of physiological indices and energetics under different system of rice intensification in north western Himalayas

Abstract

Field experiment was conducted at the research farm of CSK Himachal Pradesh Krishi Vishvavidyalaya, Rice and Wheat Research Centre, Malan during kharif 2013 with the objective to select the best seedling age and spacing of rice under system of rice intensification in terms of energetic and employment generation for mid hill con-dition of Himachal Pradesh. The experiment was laid out in 3 times replicated split plot design, assigning of three seedling ages (10, 17 and 24 days) and two spacings (20 cm x 20 cm and 20 cm x 15 cm) in main plots and four seedling vigours corresponding to four seeding rates (25, 30, 35 and 40 g/m2) in sub plots. The leaf area per plant was significantly greater in 10 days seedling age and decreased with increase in age (P=0.05). Seedling rate did not affect leaf area index in all stages except 40 DAS when 35 g/m2 seeding rate had maximum LAI. Seedling age did not significantly influence crop growth rate at any interval but it did relative growth rate and net assimilation rate between 40-70 and 70-100 DAS (P=0.05). 24 days old seedling resulted in significantly higher relative growth rate and net assimilation rate between 40-70 DAS followed by 17 days old seedlings. Maximum value of energy input (13.23) was recorded in 24 days seedling. The energy use efficiency (Energy output: input) varied from 10.6 to 11.1 under different treatments. Wider spacing supporting less plant population consumed 10 man days less than closer spac-ing of 20 cm x 15 cm.