Yield, water productivity and economics of rice (Oriza sativa) as influenced by transplanting dates, varieties and irrigation regimes in central Punjab

A two-year (2008 and 2009) field experiment was conducted at Ludhiana (Punjab), to investigate the direct and interactive effects of 3 transplanting dates (5 June, 20 June and 5 July), 2 genotypes, viz. hybrid RH 257 and in- bred PAU 201, and 2 irrigation regimes (2 days drainage period after cessation of applied water and at soil water suction of 16 kPa) on the rice (Oriza sativa L.) yield attributes, yield, water productivity and economics. The results revealed that adjusting the crop cycle by shifting of transplanting towards lower evaporative demand period (from 5 June to 5 July) resulted in significant improvement in yield and yield attributes of rice and saving of irrigation wa- ter. The number of tillers/m2, biomass, harvest index and yield increased by 20, 15, 15 and 33%, respectively, by the delay in transplanting from 5 June to 5 July. Variety RH 257 showed 1.6, 5.6 and 4.5% higher biomass, har- vest index and yield, respectively, than PAU 201. In the irrigation treatment of 2-days drainage period number of tillers/m2, biomass, harvest index and yield were 1.0, 7.8, 5.6 and 10.0% respectively more than that in soil water suction treatment. The dominant yield attributes contributing to yield were biomass and number of tillers/m2. The maximum irrigation water productivity of 0.80 kg/m3 was observed in treatment combination of rice transplanted on July 5, variety RH 257 and irrigation based on soil water suction (SWS). Irrigation-water and monitory savings were relatively more under the treatments of irrigation based on SWS, shorter crop duration and cropping cycle synchronized with lower evaporative demand