Fruit and leaf drop at early stages can be prevented by the application of :

Explanation

In low concentrations, auxins such as 2,4 D(2,4 Dichlorophenoxy acetic acid) are useful in preventing, pre-harvest fruit drop and leaf drop. Ethylene acts as a plant growth regulator. It accelerates the development process in plants such as senescence, ripening, and abscission. Gibberellic acids (Gibberellins) are naturally occurring plant hormones that are used as plant growth regulators to stimulate both cell division and elongation that affects leaves and stems. Cytokinins (CK) are a class of plant hormones that promote cell division, or cytokinesis, in plant roots and shoots. They are involved primarily in cell growth and differentiation, but also affect apical dominance, axillary bud growth, and leaf senescence.