Extreme drought will cause the leaves and fruit to drop prematurely. Any fruit left on the tree will probably sunburn. Some 36 to 48 inches of water are needed annually, applied gradually in spring and tapering off in the fall. Hot inland areas may require 2 or 3 applications weekly, while coastal areas may need watering only once every 6 weeks, depending on the soil. If a drip system is is used, the emitters should be moved away from the trunk as the tree matures.
Most trees do well with a minimum of fertilizing.
Excess nitrogen can cause fruit drop. Spread the fertilizer evenly under the canopy in late winter or early spring. Otherwise the fruit, which is borne at the tips of the branches, may be too heavy and cause breakage. A regular program of removal of some new growth and heading others each year will improve structure and reduce alternate bearing. An open vase system is probably best.