Effect of Paclobutrazol Application on Nutrient Dynamics, Vigour and Fruit Yield in 'Alphonso' Mango ( Mangifera indica L.)

Application of Paclobutrazol to 22 year-old 'Alphonso' mango trees significantly retarded plant height, plant spread and tree volume. Number of flushes and vigour of emerging new flush also decreased significantly besides production of fewer leaves, reduced leaf area, twig length and dry matter content. Fruit yield increased significantly in trees receiving Paclobutrazol treatment, compared to 'control' trees in all four years of study. This increase was distinctly higher during the on-years 2005 and 2007 by 133% and 77%, respectively, over 'control' due to more profuse flowering and fruit-set. Differences in mineral composition of various tree parts were significant except for N and P content. Paclobutrazol application caused significant increase in Ca, Mg and Mn content in the leaf. Substantial reduction observed in dry matter content and reduced leaf area accompanied by greater removal of nutrients by increased fruit production under Paclobutrazol, application may weaken the tree significantly. The trees would then need proper and adequate nutrient management vis-à-vis untreated trees, to achieve sustainable productivity.