Mongo and Citrus are important fruits in Nepal. They occupied about 9% and 25% of total fruit cultivated areas respectively in Nepal. However, the notional productivity of mango (7.0 t/ha) and citrus (10.38 t/ha) is very low. Besides other factors, fruit drop is a serious cause of low productivity in both fruit crops. In nature, fruit drop of mango and citrus hove been found very high accounting 99% and 93.52-96.63% respectively. Considering these facts, a number of studies in fruit drop, fruit development stages and their control measures have been reviewed to attract the attention of large number of workers and extension agents for minimizing the fruit drop problem in mango and citrus. The results of the investigations showed that fruit drop is a complex  problem  involving several factors. Application of recommended dose of fertilizers with spraying 2% urea or 4% calcium nitrate containing 50 mg boric acid/lit water reduced fruit drop. Among the various growth regulators, application of NAA and 2,4-D (10-20 ppm) in mango during April to May found effective for retention of fruits in North India condition. Similarly, in citrus 2,4-D ( 10-20 ppm), 2,4,5-T and GA were found effective for controlling fruit drop. The application IAA and NAA were found ineffective due to increase the abscission zone of the fruit.

Mongo and Citrus are important fruits in Nepal. They occupied about 9% and 25% of total fruit cultivated areas respectively in Nepal. However, the notional productivity of mango (7.0 t/ha) and citrus (10.38 t/ha) is very low. Besides other factors, fruit drop is a serious cause of low productivity in both fruit crops. In nature, fruit drop of mango and citrus hove been found very high accounting 99% and 93.52-96.63% respectively. Considering these facts, a number of studies in fruit drop, fruit development stages and their control measures have been reviewed to attract the attention of large number of workers and extension agents for minimizing the fruit drop problem in mango and citrus. The results of the investigations showed that fruit drop is a complex  problem  involving several factors. Application of recommended dose of fertilizers with spraying 2% urea or 4% calcium nitrate containing 50 mg boric acid/lit water reduced fruit drop. Among the various growth regulators, application of NAA and 2,4-D (10-20 ppm) in mango during April to May found effective for retention of fruits in North India condition. Similarly, in citrus 2,4-D ( 10-20 ppm), 2,4,5-T and GA were found effective for controlling fruit drop. The application IAA and NAA were found ineffective due to increase the abscission zone of the fruit.