High temperature effects on dry matter and carbohydrate accumulation in rice during early seedling growth
1992
Singh, H. | Ingram, K.T. | Egeh, A.O. (International Rice Research Inst., Los Banos, Laguna (Philippines). Agronomy, APPA Div.)
Ambient temperature during early seedling stage is an important factor in the establishment of a rice crop even where water is available. Effect of varying temperature on dry matter (DM) and carbohydrate accumulation in rice was studied. Fifteen-day old rice seedlings were grown under 29/21, 33/25, and 41/33 deg C (day/night) in artificially lit growth chambers with 0.5 full sunlight for 10, 20 or 30 days. After the 10, 20, and 30 d exposures, the plants were returned to a greenhouse (29/21 deg C). A 29/21 deg C greenhouse treatment was kept as control. All treatments were sampled at 15, 25, 35, and 45 days after seeding (DAS). DM and carbohydrate (total sugar and starch) accumulation was significantly faster at 29/21 deg C in a greenhouse compared with 29/21, 33/25, and 41/33 deg C in growth cabinets. DM and carbohydrate accumulation increased at 33/25 deg C but further increase in temperature to 41/33 deg C reduced the same attributes. For all temperature regimes, exposure longer than 10 days resulted in significantly lower DM, and carbohydrate accumulation. DM and starch content increased following transfer from growth chamber to greenhouse, after 10 and 20 d exposure, but not after 30 d exposure to various temperatures. Brief episodes of high temperature reduced seedling growth and carbohydrate accumulation which may result in poor establishment of rice seedling under field condition
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