Partial Documentation of an Unknown Avocado Fruit Deformity

Abnormalities of avocado fruit have been described and documented previously. Their cause may be genetic, abiotic, biotic, and/or caused by cultural production practices. Mishappen fruit may result from seed abortion, incomplete closure of the carpel, fruit with two seeds, or fruit with one developed and one-aborted seed. In some cases, a longitudinal ridge of peel tissue may develop, or small individual scattered bumps may be observed. Other peel defects result from abiotic environmental conditions such as sunburn, dry winds, water stress, and mechanical injury. Biotic causes include damage from insect probing or mite feeding and disease symptoms caused by pathogens. None of these factors appeared to be responsible for the symptoms observed in the leaf and fruit samples in question. In most cases, only one or a few randomly distributed fruits throughout a grove may show peel deformities that cannot be attributed to biotic or abiotic causes. The deformities observed occurred on nearly all the fruit of an unnamed avocado scion selection on 40 top-worked trees. Fruit had superficial but pronounced protrusions one or more sections of the peel surface. There were no visible symptoms below the affected fruit epidermal layer. No cultural (e.g., chemical spray applications), fungi or bacteria, mites and/or insects cause was discernable. The terminal five to seven leaves on nearly every shoot showed mottling, chlorosis, some leaf distortion, and reduced leaf size. Symptomatic leaves were slightly deficient in calcium (Ca) and magnesium (Mg), whereas copper (Cu) levels were much higher in non-symptomatic leaves.