Rice plants have the tendency of taking up iron in the form of Fe 2+ , which is prevalent in paddy fields under flooded environments. But its deficiency or in excess of Fe 2+ in the soil affect several physiological functions of the plant. The objective of the study was to evaluates the effect of three ferrous sulphate concentration levels on the yield and yield components of lowland segregating rice populations. Three experiments were established in screenhouse 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 FeSO 4 treatment, while experiment two and three are F2 and F3 populations, respectively treated with FeSO 4 solution. Three concentration levels of FeSO 4 solution (600mg/kg of soil, 1200mg/kg of soil, and 1800mg/kg of soil,) were applied into each pots a week before transplanting in the treated experiments. Remarkable reduction in effective tiller number at 1800mg of Fe stress relative to the control was observed of 42.6% and 42.9% in F2 and F3 population, respectively. Significant reduction in grain yield of 33.5% and 36.4% at 1800mg of Fe compared to the control in F2 and F3 populations, respectively. The study showed that at 1200mg of Fe could be optimal for rice crop performance and at 1800mg of Fe becomes toxic to the plant as observed significant reduction in all agronomic traits especially in total grain yield. In F2 and F3 population, UPN 59, UPIA 2 and UPN 95 where the most stable genotypes across iron concentration levels. These genotypes could be used in population development for iron breeding programme.

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 CuSO 4 treatment, while experiment two and three is the F2 and F3 populations, respectively treated with CuSO 4 solution. Three concentration levels of CuSO 4 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.

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