Fruit Varieties Importance

Apples particularly are known to have several periods when this type of fruit drop occurs. The first fruit drop is right after the flower petals fall off and the life span of the tiny fruit is not more than three weeks. The fruits that drop are understandably the ones that did not get pollinated in time or the sperm cells from the pollen failed to reach the ovary.
With regard to most fruit varieties, lack of pollination occurs due to cold or wet weather or honeybee decline. Again, if the flower buds are exposed to freezing weather, then fruit drop may become inevitable.
A second drop takes place during late May or June when the fruits are about the size of marbles. This second drop is quite often called the "June drop." Apples and pears are notoriously prone to this second drop, as a result of competition between fruits for resources. Premature cherries are less likely to drop as readily as apples and pears and may stay on the tree for a longer period.

What people call a mid-summer fruit drop pertains mostly to plums. In apples, pears and cherries, mid-summer fruit drop is rare, unless there is a pest or disease infestation. Pre-harvest drop, occurs when fruit is infested with wormy pests that may cause premature ripening and fruit fall. It is a thumb rule that the picking season for fruits has commenced as soon as few mature fruits begin to fall off.

Experts say that most trees produce large quantities of flowers much in excess for a full crop and this is the chief reason why they are shedding fruits. Only one flower bloom in twenty is needed for a good crop, fruit drop in June can be nature's way of thinning the crop so the remaining fruit can survive and reach full size.

Most fruit trees have at least two seasons of fruit drop. The first occurs immediately after bloom and this is due to incomplete pollination. The second drop occurs three to four weeks later. The second called June drop is usually bigger and more dramatic because the fruits have developed to a larger size.

Source : articlesbase