Submitted to: Australian Nutgrower
Publication Type: Trade Journal
Publication Acceptance Date: March 14, 2006
Publication Date: August 1, 2006
Citation: Wood, B.W. 2006. Fruit drop in pecan. Australian Nutgrower. 20(3):14-17. Interpretive Summary: Excessive fruit-drop is a major problem affecting many pecan varieties. Information is presented that identifies the most common causes of premature fruit-drop. These causes are low energy reserve pool, poor pollination, fruit-feeding insects, nutritional deficiencies, and genetic incompatibilities. This information enables farmers and home owners to better protect against crop loss in pecan.
Technical Abstract: Most dropped fruit of pecan are associated with the first and second drops of the four drop periods typical of most pecan varieties. The first drop is most commonly due to insufficient tree energy reserves as a consequence of physiological stresses during the previous growing season. The second drop, the June-drop, is most usually associated with poor pollination tied to weather events, or to non-overlap of pollen dispersal by pollinators, or to excessive distance from pollinations, or to damage by fruit feeding insects such as nut casebearer. Nutritional deficiencies can also limit fruit-set. Elements of special importance are boron, calcium, and nickel.