Relationship of Daily Growth and Development of Peach Leaves and Fruit to Environmental Factors

Abstract

A procedure was developed for detecting daily changes in the rate of growth and development of leaves and fruit of peach [ Prunus persica (L.) Batsch.]. Quantitative morphological stages of leaf and fruit development were determined for 3 cultivars, transformed into growth rates, and used as dependent variables for regression on a variety of daily environmental variables: maximum and minimum temperature, degree hours, precipitation, solar radiation, estimated soil moisture (Thornthwaite method), 1- to 3-day lags of these variables, quadratic and cubic transformations, and selected 2-variable products of the basic variables. Prediction equations performed well in tests from different years, locations, and cultivars. Maximum and minimum temperature, precipitation, soil moisture, and age were the most important variables for the leaf growth prediction equation. In the fruit growth prediction equation, maximum and minimum temperature, soil moisture, and age were most important.