Received: 09-01-2017 / Accepted: 26-03-2017
Pot - experiments were laid out in a randomized completely block (RCB) with five replications at the green house of Vietnam National University of Agriculture in autumn cropping season 2016 to investigatephotosynthesis and translocation of non - structural carbonhydratesin an early maturing rice line DCG72 under three levels of potassium application (no potassium application - K0: 0 g K2O/pot; low potassium application level - K1: 0.5g K2O/pot and high potassium application level K2: 1.0 g K2O/pot). The control variety was KD18. The results showed that photosynthetic intensity of two genotypescorrelated with individual productivity and increased withincreasing K level from K0 to K1. Increased K level,K2, reduced leaf area and chlorophyll in DCG72.. Translocation of non-structuralcarbonhydratesof two genotypes was significantly higher at K1 than K0 and K2 within DCG72, higher than KD18 at K1. Individual plant productivity in two rice genotypes increased withincreased K level from K0 to K1only. Individual plant yield of DCG72 was similar to that ofKD18 at K0, but higher than that in KD18 at K1 due to high spikelets per panicle, filled grain rateand 1000 grain weight.At K2, howeverindividual plant yield of DCG72 was lower than in KD18due to low spikelets per panicle and filled grain rate.