Effect of irrigation schedules on growth and yield of aerobic rice (Oryza sativa) under varied levels of farmyard manure in Cauvery command area

Field experiments were conducted during summer 2005 and 2006 at Mandya, Karnataka to study the effect of irrigation regimes in conjunction with varied levels of farmyard manure (FYM) on growth and yield of aerobic rice (Oryza sativa L.). The treatments consisted of 4 levels of irrigation based on IW (irrrigation water) CPE (Cumulative Pan Evaporation) ratio (2.5, 2.0, 1.5 and 1.0 with an IW of 5 cm) and three levels of FYM (0, 10 and 20 tonne/ha) was laid out in split plot design with three replications. The results revealed that application of 20 tonne FYM recorded significantly more number of productive tillers/hill, filled spikelets/panicle and thus more grain yield (6.01 and 6.44 t/ha during 2005 and 2006, respectively). However, no FYM application recorded higher B:C ratio (1.02). Irrigation scheduled at IW/CPE ratio of 2.5 recorded significantly higher yield attributes and grain yield (6.21 and 6.58 tonne/ha during 2005 and 2006, respectively) and same treatment recorded higher B:C ratio. However, irrigation scheduled at IW/CPE ratio of 1.0 recorded higher water use efficiency (52.09 kg grain/ha-cm). The N, P and K uptake was higher with application of 20 tonne FYM and with irrigation scheduled at IW/CPE ratio of 2.5.