Integrated Approach to Control of Fruit Drop and Improvement of Yield in Kinnow (Citrus nobilis X Citrus deliciosa)

Abstract

Fruit drop is a major problem with Kinnow mandarin in all fruit growing regions of the world. Kinnow growers suffer a greater economic loss when natural fruit drop (98.0 to 99.5 %) is accelerated by pathogenic infection, insect-pest infestation, and physiological or hormonal imbalance due to poor orchard management. The application of fungicides to minimize pathogenic attack; 2,4-D (2,4-Dichlorophenoxyacetic acid) to maintain hormonal balance; and KNO3 (Potassium nitrate) to maintain electrolytic balance and efficient utilization of nutrients for developing resistance against insect infestation has greater potential to reduce fruit drop in Kinnow. The fungicides, namely; Zeneb 75WP (0.25 %), Carzim-50 (0.1 %), Curzate M8 (0.25 %), COPRUS 50WP (0.3 %), and Cyproconazole 25EC (0.1 %), in combination with 2,4-D @ 20 ppm and KNO3 @ 1 %, were applied twice, in September and October, and the number of fruits fallen on the ground were counted to determine fruit drop. It was observed that application of T3 [Curzate M8 (0.25 %) + 2,4-D (20 ppm) + KNO3 (1 %)] was an excellent treatment for the integrated management of fruit drop in Kinnow as it had ensured the lowest (1.90-entomological, 3.53-pathological, and 4.75-physiological) fruit drop percentage with the highest fruit yield (432 fruits per plant).