UF/IFAS Scientist Research Citrus Fruit Drop

June FloridAgriculture eNewsletter

UF/IFAS citrus scientists Tripti Vashisth and Fernando Alferez are studying what causes pre-harvest fruit drop in Hamlin and Valencia trees. The drop in fruit leads to losses for farmers because there is less fruit to harvest.

A 10% to 15% fruit drop is normal for a healthy tree. With citrus greening, scientists and growers have seen pre-harvest fruit drop increase in the last decade.  In the 2012-2013 season, there was about 25% crop loss due to pre-harvest drop.  Now, depending on the citrus variety, the drop is upwards to 50%.

The two UF/IFAS scientists are looking into the effect of removing “fruitlets’’ – fruit that’s less than 2 centimeters in diameter – from so-called “off-blooms.”

“Typically, healthy citrus trees bloom early in spring, and they may have another wave of flowers later in the spring, but it is atypical for the tree to bloom in late summer,” said Alferez.

Preliminary experiments show that removing “fruitlets” from off-blooms when Hamlin oranges are mature results in more mature fruit hanging onto citrus trees, causing a yield increase because the mature fruit drops less.