Impact of heat stress during harvest on peach yield reduction

This study evaluates the impact of heat stress during the harvest period on peach yield reduction across South Korea, a country where average temperatures have been steadily increasing due to climate change. Peaches, a nutritionally important fruit and a major Korean crop, are harvested in summer and may be affected by high temperatures. To assess the relationship between thermal stress and yield loss, we developed a logistic regression model using municipal-level yield statistics and climate indicators centered on the harvest window of the widely cultivated ‘Cheonjungdo Baekdo’ cultivar. Key explanatory variables were average maximum and minimum temperatures during the growth period, number of hot days exceeding 30°C, cumulative heat stress above 30°C around the harvest period, and the duration of the fruit development period. The results showed that thermal indicators were significant predictors of low yield. Prolonged heat exposure near the harvest period and elevated nighttime temperatures increased the risk of yield reduction, while higher maximum temperatures during the growth period were associated with improved productivity. In particular, number of hot days had a positive correlation with low yield, while cumulative heat intensity showed a negative association. This suggests that continuous heat exposure may negatively affect peach yield. These findings highlight a complex interaction between heat stress and fruit development. As extreme summer temperatures become more frequent due to accelerating climate change, adaptation strategies such as adjusting harvest timing and selecting heat-tolerant cultivars will be increasingly important for sustainable fruit production.