Normally there is a fairly heavy drop (about 80 - 90%) of small fruit beginning shortly after the blossoms
fall and continuing until the fruit is 0.5 inch or more in diameter. Older fruit may also drop.
Citrus naturally adjusts the amount of fruit carried on the tree, so some fruit drop is normal. Excessive
drop of older fruit may have several causes: lack of water or fertilizer, heavy pruning, sudden changes
in temperature (especially sudden hot temperatures at fruit set or shortly after), or insect infestation.
It is not always possible to avoid excessive fruit drop, but it can be kept to a minimum by giving the
trees the best possible care. It is especially important to irrigate carefully, avoid excessive pruning,
and keep pests under control.
drop shortly after petals fall