Impact of Temperatures During Fruit Development on Fruit Growth Rate and Qualities of ‘KU-PP2’ Peach

Abstract

In protected agriculture, optimum temperature management is crucial for enhancing fruit productivity and maintaining cost-effective production. The aim of the present study was to investigate the effects of temperature on peach fruit development and quality. Container-grown 'KU-PP2' peach trees grafted on low-chill peach rootstocks were cultivated under controlled conditions at different temperatures (20, 25, and 30°C) during fruit development for two years (2020 and 2021). Fruit growth rates were calculated by measuring fruit diameter every 3 d from fruit setting to first harvest; fruit quality and phytochemistry were analyzed at harvest. Growing temperature markedly affected fruit growth, maturation, and fruit quality. The development of fruit in all treatments exhibited double sigmoid growth curves that included three stages (S1, S2, and S3). Fruit growth rate during S1 and S2 stages was increased, and fruit development period was significantly shortened with an increase in temperature. Contrary to the duration of S3, which was longer at higher temperatures, fruit grown at a high temperature (30°C) ripened by 12-18 days earlier than those grown at low-temperature regimes. In addition, high-temperature conditions were also associated with reduced fruit quality (size, weight, and sweetness), but enhanced development of red coloration. Therefore, even though high-temperature conditions can accelerate early fruit expansion and hasten fruit maturity, such conditions also have negative effects on important agronomic fruit traits.