Effect of elevated CO2 and temperature on growth and yield of winter rice under Jorhat condition

Abstract

A pot experiment was conducted during kharif, 2018 inside CO2 Temperature Gradient Tunnels (CTGT) to assess the effect of elevated CO2 and temperature [T0: ambient temperature & ambient CO2, T1: elevated temperature (ambient +1°C) & elevated CO2 (ambient+25% of ambient) and T2: elevated temperature (ambient +2°C) & elevated CO2 (ambient + 50% of ambient)] under three different transplanting dates (D1: 25th June, D2: 10th July and D3: 25th July) on growth and yield of rice in Jorhat district of Assam. The result showed that occurrence of different phenological stages was earlier under elevated CO2-Temperature conditions resulting in reduction of crop duration by about 8-15 days. On the other hand,days to tiller initiation increased whereas days to panicle initiation, flowering and physiological maturity reduced with delay in transplanting. Yield attributing parameters were improved under elevated CO2-Temperature condition. With respect to dates of transplanting, D2 recorded higher number of panicles hill-1 (17.9) and higher filled grains panicle-1 (156.6). Higher grain yield (55.9g hill-1) was found under T2 which was at par with T1 and it was significant higher over the ambient. Grain yield was significantly reduced when transplanting was delayed after 10th July. The results revealed that the growth and yield of rice was found to be better under elevated CO2-temperature levels when transplanted on 10th July.

Keywords

• CO2-Temperature Gradient Tunnels, climate change, dates of transplanting, phenology