Standardization of Different Concentration of IBA & NAA on Commercial Propagation Method of Litchi (Litchi Chinensis Sonn.)

The study was conducted at the Horticultural Research Centre, College of Horticulture, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut (U.P.). with the objectives to standardize the most effective concentration and combination of IBA and NAA for commercial propagation of litchi by air layering. The experiment was laid out in a Randomized Block Design with nine treatments, including IBA, NAA, and their combinations. Among the different treatments evaluated, the combined application of IBA 2000 ppm + NAA 2000 ppm (T9) emerged as the most effective across multiple parameters. Physiologically, this treatment resulted in the earliest root initiation (22.0 days), the highest number of primary roots (21.3) and secondary roots (29.3), the longest root length (7.90 cm), and the maximum root thickness (1.87 mm), indicating superior rooting efficiency. It also recorded the highest rooting percentage (80.0%), while reducing the days to initiation of new leaves (15.0 days), thereby accelerating establishment. In terms of vegetative performance, T9 achieved the maximum total number of leaves (18.0) and the highest survival percentage after transplanting (85.0%), while recording the lowest mortality percentage (10.0% at 60 DAT). The mean performance of all IBA + NAA combined treatments was superior to IBA or NAA alone, confirming their synergistic effect in promoting rooting and survival. Overall, the study clearly demonstrated that the combined application of IBA 2000 ppm + NAA 2000 ppm was the most effective treatment for improving rooting success, survival percentage, and overall growth of litchi air layers under the conditions of western Uttar Pradesh. This treatment offers a practical and reliable propagation method for commercial litchi cultivation, ensuring higher survival, reduced mortality, and vigorous planting material for orchard establishment.