Determining Thermal Time and Base Temperature Required for Fruit Development in Low-chilling Peaches

Abstract

Base temperature (temperature at which growth begins) and thermal time required for fruit development (degree-days needed from full bloom to commercial harvest) were calculated for 5 low-chilling peach and nectarine [Prunus persica (L.) Batsch] cultivars grown in different climatic conditions. Base temperatures ranged from 2.5° to 4.4°C, and thermal time from 1028 to 1432 degree-days when the calculated base temperatures were used. Use of the calculated base temperatures rather than 10° base temperature reduced variability in predicting thermal time for fruit development.