Avocado Fruit Abnormalities and Defects Revisited

Occasionally an observant grower will note the presence of defective avocado fruit on a tree or in a harvested bin. At the packinghouse grading table, however, these defects are more obvious given the increased volume of fruit. In fact, Art Schroeder in 1953 suggested this approach for observing unusual fruit abnormalities. Abnormal fruit can occur in all varieties and has been discussed several times in the avocado literature (Blumenfeld and Gazit, 1974; Coit, 1928; Hodgson, 1935; Horne, 1929, 1934; Kadman et al., 1973; Platt, 1972; Schroeder, 1953; Tomer et al., 1980, Zamet, 1996). What follows is a review of these descriptions with photographs from the ‘Hass’ variety depicting various fruit abnormalities and defects. As Schroeder suggested, the description of fruit abnormalities is of interest since “they (the abnormalities) may suggest certain aspects of the fruit morphology which are otherwise difficult to ascertain.” Fruit abnormalities and defects can either be induced by genetic factors such as somatic mutations that occur during cell division or can be induced by external factors such as water stress, wind or by insects. The expression of the defect, in particular, those arising from external factors will depend on the stage of fruit development at which it occurs. It is likely the vast majority of young affected fruit drop prior to harvest and thus go undetected, but some persist to harvest only to be downgraded at the packinghouse.