Canopy Management of Unproductive Mango (Mangifera indica L.) Orchards

An overcrowded, dense and unproductive mango orchard of Himsagar variety (40 years old) spaced at 8x8 m was severely pruned at 4 and 5 - meter height in the month of December, 2001 at the Horticultural Research Station of Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal, India with the objective to improve productivity. Apart from 2 pruning levels (at 4 and 5 - metre height), nutrients at 3 levels viz. I) 500 g N + 250 g P2O5 + 500 g K2O + 50 kg FYM per plant, ii) 800 g N + 300 g P2O5 + 1000 g K2O + 50 kg FYM per plant and iii) 100 kg FYM per plant and Paclobutrazol at 2 levels viz. 3 and 4 g per meter of canopy spread was employed in the present experiment. The experiment was laid out in an augmented-3 factor factorial CRD with 3 replications and 12 treatments along with a control. The efficacy of pasting the cut ends of pruned branches with cow dung slurry proved equally effective with copper oxychloride in preventing disease and pest infestation. Pruning at 4 meter height along with the application of 800 g N, 300 g P2O5 and 1000 g K2O along with 50 kg of FYM resulted in highest shoot length, shoot girth, number of leaves per shoot and tree spread in both the north-south and east-west direction. The pruned trees with the same treatment also produced maximum yield (40 kg/plant and 8.00 tonnes/ha) with a planting density of 240 trees per hectare in the third year (2004) after pruning when applied with Paclobutrazol at 4 g per meter of canopy spread in the fourth week of September, 2003. Both pruning and the nutrient levels significantly influenced the leaf area index (LAI) in the third year after pruning. The net return from the rejuvenated orchard during the first three years remained around Rs. 2,55,000.00 inclusive of return from the sale of cut branches and fruits produced in the third year as compared to the net return of Rs. 70,000.00 only from the non-rejuvenated orchard. It appears from the results that the old mango orchards could be made productive by adopting rejuvenation.