Effect of high density planting systems on physiological and biochemical status of rejuvenated mango plants of cv. Amrapali

Mango trees grown under high density planting systems show a gradual decline in yield after 11–12 years due to overcrowding of canopies. To find out the effect of high density planting systems on physio-biochemical parameters of mango, an experiment was conducted on an old senile, rejuvenated high density cv. Amrapali orchard over two consecutive years. High density planting systems showed significant effect on physiological, biochemical and nutritional parameters of plants. Among the different planting systems, plants under cluster planting system recorded the highest leaf area (156.68 cm2), transpiration rate (3.77 m mol−1 m−2s−1); and N (1.28%) P (0.20%) and K (0.54%) contents. The maximum leaf relative water content (87.63%) was noted in plants under square planting system, while, the photosynthetic rate (8.36 μmol CO2 m−2 s−1) was highest in hedge-row planting system. The stomatal conductance (0.17 μmol CO2 m−2 s−1) was the highest in plants under double-hedge row planting system. The highest internal carbon concentration was recorded in paired planting system, while the maximum chlorophyll ‘a’ (1.50 mg g−1), chlorophyll ‘b’ (0.65 mg mg g−1) and total chlorophyll (2.02 mg g−1) contents were found in plants under square planting system. The highest total phenolics (53.09 mg g−1) content was recorded under paired planting system. The micronutrient contents in plants, viz. Cu, Zn, Fe and Mn also differed among different planting systems.