Influence of foliar application of nutrients and growth regulator on fruit drop, yield and fruit size and quality in kinnow mandarin

The present investigation was carried out on the 15-year-old Kinnow mandarin trees. Nutrients (KNO₃, ZnSO₄), growth regulator (2, 4-D) and their combinations (KNO₃ 1% + 2, 4-D 10 ppm, KNO₃ 2% + 2, 4-D 10 ppm, KNO₃1% + ZnSO₄0.5%, KNO₃2% + ZnSO₄0.5% and ZnSO₄0.5% + 2, 4-D 10 ppm) were applied as foliar spray in first week of May and August. Fruit drop was lowest (53.5%) with ZnSO₄ 0.5% + 2, 4-D 10 ppm. Fruit length and breadth (6.05 and 6.98 cm), fruit weight (168.6 g), fruit yield per tree (43.7 kg), TSS (10.6%) and ascorbic acid (25.81 mg/100 ml juice) were recorded highest with KNO₃2%, KNO₃2% + 2, 4-D 10 ppm and KNO₃2% + ZnSO₄ 0.5%, respectively. Highest juice content (49.72%) was recorded with 0.5% ZnSO₄.