Effect of paclobutrazol on root activity of mango (Mangifera indica).
Kotur S. C.
Author Affiliation: Indian Institute of Horticultural Research, Bangalore, Karnataka 560 089, India.
Indian Journal of Agricultural Sciences 76 : 143-144
Abstract : A study was conducted during 2004, in Bangalore, Karnataka, India, to evaluate the effect of paclobutrazol (3.75 g a.i./tree) on the root activity of 19-year-old 'Alphonso' mango (Mangifera indica) trees. Soil injection technique was employed, using 32P as tracer. The intensity of root activity significantly declined to 575-9086 dpm/g dry matter under paclobutrazol application from 910-10?739 in the control during 15-60 days after application of the tracer. The active roots of mango trees were relatively uniformly distributed throughout the soil volume in the control compared with paclobutrazol application. In the latter treatment, the active roots significantly bunched toward the trunk and close to soil surface leading to nearly one-half of the roots (44.56-58.02%) migrating to the zone of 80 cm distance and 25 cm depth. Consequently, farther distance and deeper rooting volume of the soil showed significantly sparser root activity. These results call for a more detailed investigation to evaluate the effect of paclobutrazol on the root activity during annual growth cycle of mango tree to standardize the fertilizer and irrigation management practices of mango trees for sustained fruit production.