Apple Fruit Growth as a Measure of Irrigation Control1

Abstract

Fruit growth rates and yields of apple ( Malus domestica Borkh.) collected from irrigation experiments from 1967–1980 in the Hula Valley of Israel indicated that the seasonal course of growth rate expressed in volume units was linear in optimal irrigation regimes regardless of the method of irrigation. Equations for converting the circumference measurements to volume units were developed for 5 commercial apple cultivars. Typical fruit volume growth lines are presented for growers use to control irrigation regimes in conjunction with the common pan evaporation coefficients.