Climate Change Impacts on Fruit Crop Productivity: Phenological Disruption, Reproductive Failure and Quality Trade-offs under Rising Temperature

Climate change, particularly rising temperature, has emerged as a major constraint on fruit crop productivity worldwide. This review synthesises current knowledge on how elevated temperatures influence phenological development, reproductive processes, source–sink relationships and fruit quality in perennial horticultural systems. Fruit crops are highly sensitive to thermal variability because of their long life cycles and dependence on precise environmental synchronisation during flowering and fruit development. Heat stress disrupts pollen viability, pollen germination, pollen tube growth and ovule function, leading to reduced fertilisation success and fruit set. Elevated temperatures also accelerate phenological transitions, shorten flowering windows and increase the exposure of reproductive tissues to supra-optimal conditions. At the physiological level, heat stress reduces photosynthetic efficiency and alters carbohydrate metabolism, thereby limiting assimilate availability for developing fruits. This imbalance between source activity and sink demand contributes to fruit abortion, reduced yield and poor fruit development. Fruit quality is also affected through changes in sugar–acid balance, reduced phytochemical accumulation and decreased firmness and shelf life. The review further considers adaptation strategies, including breeding for heat-tolerant genotypes, orchard-level microclimate management and molecular tools such as genomics and gene editing. Although these approaches offer promising avenues for reducing climate-induced losses, their effectiveness remains constrained by genetic limitations and trade-offs between stress tolerance and fruit quality. Overall, the findings emphasise the need for integrated strategies combining physiological understanding, genetic improvement and agronomic management to sustain fruit productivity under warming climates.