Fertilizers and Plant Growth Promoters Influence the Fruit Quality of Young ‘Kinnow’ Mandarin Orchards

Inferior quality fruit from young ‘Kinnow’ orchards along with tree decline in early age is a significant challenge to citrus growers in Pakistan. Improving fruit quality of young orchards is indispensable to obtain early profit from an orchard but is often neglected by the growers. A project was planned to assess the impact of fertilizers (phosphorous and potassium) as well as plant growth promoters (Wokozim and Isabion) on fruit quality of young orchards. Citrus trees were treated with 0.250 kg tree −1 of phosphorous (P), 0.250 kg tree −1 of both P + potassium (K), 0.250 kg tree −1 of K and one kilogram of Wokozim (granular) tree −1 before flowering. Foliar application of Wokozim (2 mL L −1 ) was carried out once at the flowering (FL) stage, whereas Isabion (5 mL L −1 ) application was performed at FL, pea and egg stage. Fruit were harvested at commercial harvest maturity and analyzed just after harvest and after 7 days at shelf-life conditions. Wokozim application (1 kg tree −1 ) significantly reduced rind thickness (4.10 mm) as compared to control (4.66 mm).K (0.250 kg tree −1 ) significantly retained ascorbic acid concentrations (48.10 mg 100 mL −1 ) after shelf-life. Wokozim applied as soil treatment and foliar supplementation significantly improved reducing sugars (1.6%) after shelf-life. Wokozim and Isabion applications also reduced respiration and mass loss (%). In conclusion, soil and foliar supplementation of Wokozim improves quality parameters of fruits from young ‘Kinnow’ mandarin orchards.