Study on the Individual Impacts of Mineral nutrients N, P and K and their Combinations on the Physiology and Growth performance of Pongamia pinnata (L.) Pierre seedlings to assess Quality

The demand for raising energy plantation as a sustainable and dependable alternative indigenous energy source to commercial fuel is increasing due to the rapid depletion of fossil fuels and degradation of environment which resulted from over exploitation. The success of energy plantation is primarily dependent on the quality of tree seedlings planted in the field. In this context a study was conducted to determine the influence of mineral nutrients N, P, K and their combinations on the quality of Pongamia pinnata (L.) Pierre seedlings. Parameters like total leaf area, total chlorophyll, leaf starch concentration, CO2 assimilation rate and total dry biomass production were selected and analysis was carried out in the nursery level. In general, nitrogenous nutrient treatments N, N+P, N+K and N+P+K significantly increased total leaf area, total chlorophyll, CO2 assimilation rate and biomass production of P.pinnata seedlings compared to control. However the influence of non-nitrogenous nutrient treatments P, K and P+K caused only a marginal impact. Combination of N and K nutrients was found to have contributed maximum improvements in the seedling quality whereas P nutrient alone contributed least.