EFFECT OF CULTURAL-PRACTICES ON PRODUCTIVITY AND ECONOMICS OF RICE (ORYZA-SATIVA)-WHEAT (TRITICUM-AESTIVUM) CROPPING SYSTEM IN PLATEAU REGION OF BIHAR

An experiment was conducted during 1984-86 to find out the effect of date of establishment, fertility level, plant density and plant-protection measure each at 2 levels on the productivity and economics of rice (Oryza sativa L.)-wheat (Triticum aestivum L. emend. Fiori & Paol.) cropping system. Transplanting of rice on 8-9 July and sowing of wheat on 20-22 November recorded higher grain (4.2 and 3.3 tonnes/ha) and straw yields (4.5 and 4.5 tonnes/ha), greater net returns (Rs 4 495 and Rs 4 686/ha) and better cost: benefit ratios (1.62 and 1.51) in rice and wheat grown in sequence than their late establishment. Application of N,P and K @ 100, 22 and 25 kg/ha respectively to both rice and wheat increased their productivity (4.3 and 3.5 tonnes/ha) and net return (Rs 4 419 and Rs 4 894/ha) as well as the cost: benefit ratio (1.47) of wheat. High plant density gave higher yields of grain (3.3 tonnes/ha) and straw (4.4 tonnes/ha) and greater net return (Rs 4 509/ha) in wheat than low plant density; but it had no effect on rice. Plant-protection measure increased the grain yield (4.2 tonnes/ha) of rice and the grain (3.2 tonnes/ha) and straw (4.4 tonnes/ha) yields of wheat and net return (Rs 8 631/ha) in rice-wheat sequence. Early establishment, high fertility level, high plant density and adequate plant-protection measures increased the rice yield by 27.7, 39.7, 11.8 and 20.8% and the wheat yield by 25.4, 44.7, 20.8 and 9.1% respectively compared with late establishment, low fertility level, low plant density and insufficient plant-protection measures.