Effects of Copper (Cu) on Yield Components and Associated Traits in Segregating Populations of Lowland Rice (O. sativa L.)

Trace elements are very critical for rice growth of which Cu is one of the essential trace elements for rice and excess of cupper becomes toxic to rice growth. The aim of this study was to determine the productivity increase in rice crop and genotype reactions to application of Copper under the tropical rainforest condition. Three experiments were established concurrently in randomized complete block design in three replications in pots. Treatment comprised of 6 breeding lines each from two rice populations of F2 and F3 generations and two popular checks. Experiment one is the control without CuSO4 treatment, while experiment two and three is the F2 and F3 populations, respectively treated with CuSO4 solution. Three concentration levels of CuSO4 solution (15mg Cu /kg of soil, 30mg Cu /kg of soil and 60mg Cu /kg of soil) were applied into each pots a week before transplanting in the treated experiments. This study observed that at 30mg of Cu/kg of soil is the optimum level for rice performance based on these experiments beyond, reduction in rice performance. Reduction of 24.92% and 22.12% of total grain yield of F2 and F3 populations at 60mg of Cu/kg of soil as compared to the control were recorded, stable and high yielding genotypes across the copper concentration levels were identified for copper breeding programme.