Effect of increased nighttime temperature on dry matter production and nutrient absorption in double cropping rice

n experiment was conducted under different glasshouse conditions to determine the effect of nighttime temperature increase (NTI) on dry matter production and nutrient absorption in double cropping rice. No significant effect of NTI on dry matter production in early rice is noted. However, NTI significantly increases dry matter production in late rice. In early rice, NTI enhances dry matter accumulation before panicle differentiation, but decreases it after that. In the case of late rice, dry matter accumulation is enhanced by NTI, except during panicle differentiation to heading. Flag leaf senescence in early rice is accelerated by NTI, but no similar effect is noted in late rice. There is less obvious impact of NTI on total nitrogen accumulation than on P and K accumulation. In early rice, NTI only benefits crop nutrient absorption before panicle differentiation, but after that NTI inhibits nutrient absorption. However, the opposite tendency is observed before and after heading in late rice. The study therefore suggests that the effect of NTI on dry matter production and nutrient absorption is different between early and late rice, and among growth stages.