Growth and abscission of avocado fruits (Persea americana Mill.) cv. Fuerte

Abstract

In a commerical orchard of 18-year-old trees, 1250 fruits were chosen for observation. The majority of them abscised during the first weeks after anthesis. Afterwards, the abscission gradually descreased, however, in the meantime three additional waves of more intensive shedding occurred which were best visible when the Relative Abscission Rate (RAR) was calculated. The peaks in the RAR curve were preceded by a decrease in the Relative Growth Rate (RGR) of persistent fruits, which suggests that nutritional or other stresses occurred in the whole branch. In the period from May 15th to July 15th, predominantly the smaller fruits were abscised, later on, however, fruits of the same size as the persistent ones were shed. The formula for calculating RAR and RAR is shortly discussed.