Performance of Low- and High-Chill Peach Cultivars in Tropical Highland Environments: Impacts on Yield, Phenology, and Fruit Quality

Peach cultivation in tropical and subtropical regions is limited by insufficient winter chilling, which constrains dormancy release, flowering, vegetative growth, and yield. This study evaluated chilling requirements, phenology, growth, yield, and fruit quality of ten peach ( Prunus persica L) cultivars under tropical mild-winter conditions using the Dynamic Model (Chill Portions, CP), with Chill Hours and Utah Chill Units as references. Low-chill cultivars (8–18 CP; Earlygrand, Flordadown, Tropicsnow ) consistently exhibited synchronized flowering, high bloom density (≥ 75%), vigorous vegetative growth, stable yields (16–20 kg/tree), and superior fruit quality. Intermediate-chill cultivars (18–26 CP) showed partial dormancy release and variable productivity, while high-chill cultivars (30–38 CP; Transvalia, Springcrust, Novadonna ) displayed delayed phenology, poor bud break, restricted growth, low yield (1–2.5 kg/tree), and high variability. Strong negative correlations between CP and vegetative growth (r = − 0.88 to − 0.91) and yield (r = − 0.90 to − 0.92) validate the Dynamic Model’s physiological relevance in tropical climates. These findings provide actionable guidance: low-chill cultivars are optimal for consistent flowering, robust growth, and high-quality fruit production in tropical mild-winter regions, whereas intermediate- and high-chill cultivars require careful evaluation or are unsuitable. Cultivar-specific chilling assessment is essential for optimizing peach performance in tropical production systems.