Stem pruning severities affect growth, physiological and quality consequences in high density planting system of mango (Mangifera indica) in Shiwalik foothills

The study evaluated the influence of shoot pruning intensities on physiological and quality consequences of mango under square system of planting between 2014 and 2016 in Shiwalik foothills. Three mango cultivars, viz. Mallika, Dashehari, and Amrapali, planted under high density were selected purposely. Tip pruning of frost injured shoots significantly influenced growth, flowering, yield and quality traits of the cultivars compared to un-pruned trees. The results revealed early flower initiation with peak period of flowering among the treatments. Shoot pruning slightly delayed but more uniform flowering comparative to control. After 20th harvest season, the cultivar significantly affected generative parameters (TCSA, TCV, CA and yield efficiency). Number of sprouted shoots per scaffold branch (primary, secondary) was highest in Dashehari followed by Amrapali and Mallika irrespective of shoot differentiation. Dashehari recorded maximum length of panicles, length of flowering shoot, number of panicles/shoot, fruited panicles, fruit set, and fruit retention with least fruit drop when the shoots were pruned in frost affected twigs (terminal branches) shoot differentiation. The best yield and yield efficiency over the 20th leaf harvest was recorded in Mallika followed by Amrapali and Dashehari. Variable shoot pruning intensities showed significant effects on fruit physical-biochemical traits and foliar nutrient concentration of the cultivars. DOP indexing showed close agreement to diagnose N, P, K, Mg, Fe, Cu, Zn and Mn excess among different cultivars studied. PCA of agromorphometric and fruit quality traits was also worked out. prin4 accounted for 99.5% (agro-morphometric traits) and 97.9% (fruit quality) of the cumulative variance of cultivars. PCA-F1 had the highest positive loadings (plant height, tree girth, annual shoot extension growth TCSA, and TCV) followed by PCA-F2 (yield). None of the significant differences were obtained when the calculated factor scores of PCA-F1, PCA-F2 and PCA-F3 for attributes analyzed. Conclusively, shoot tip pruning could be recommended for restoring maximum production and quality fruits in high density square planting system of mango.