Abstract

Several models have been developed elsewhere for apple fruit growth in order to predict harvest and aid marketing management, but models are not available for local growing conditions in Chile. For this reason, apple diameter was investigated during two growing seasons (1999/00 and 2000/01) to develop models for predicting apple size (cv. Royal Gala) in the Region of Maule, Chile. Models for predicting apple diameter as a function of growing-degree days were developed for 5 commercial orchards, using the logistic model. Results indicate that the logistic model was able to predict apple size with a determination coefficient (r(2)) of 0.99. There was also a good association between fruit fresh weight and fruit diameter (r(2) = 0.99).