Influence of phosphorous and potassium nutrition on growth, yield and fruit quality of Gala Mast apple

Abstract

The present study was conducted in the experimental field of the Division of Fruit Science, SKUASTKashmir, Shalimar Campus, Srinagar (Jammu and Kashmir, India) on four-year-old Gala Mast apple grafted on MM106 rootstock under high-density plantation (3m × 3m) to standardize the optimum dose of phosphorous and potassium. Sixteen treatment combinations of four levels of phosphorous (25 g, 50 g, 75 g, and 100 g/ tree) and potassium (150 g, 200 g, 250 g, and 300 g/tree) were tested. As a result, the maximum increase in tree height (55.89 cm), tree circumference (2.31 cm), annual shoot extension (47.13 cm), leaf area (42.00 cm2 ), fruit length (6.52 cm), fruit diameter (7.31 cm), fruit weight (168.26 g), fruit volume (185.48 cm3 ), yield (6.85 kg/tree), total soluble solids (15.85°B), total sugars (13.17 %), ascorbic acid (5.89 mg/100 g), and anthocyanin content (9.27 mg/100 g) were observed with the application of phosphorous @ 100 g + potassium @ 300 g. Highest fruit firmness (9.81 kg/cm2 ) was recorded when phosphorous @ 100 g + potassium @ 150 g was applied. In contrast, minimum acidity (0.197 %) and maximum TSS/acid (76.47) ratio were recorded by using phosphorous @ 25 g + potassium @ 300 g. Therefore, it can be concluded that phosphorous @ 100 g/tree in combination with potassium @ 300 g/tree proved most economical and effective in improving apple cv's growth, yield, and quality.