Estimating apple diameter from fruit mass measurements to time thinning sprays

The relationship between fruit mass and fruit diameter for apple fruit 2 to 26 mm (0.08 to 1.04 inches) in diameter was evaluated for two cultivars sampled from several orchards for three years. A single regression model was appropriate for all combinations of year, cultivar, and orchard. The model was used to develop a chart to quickly estimate fruit diameter from fruit mass. These fruit diameter estimates can be used by commercial fruit growers to time chemical thinner sprays.