This study aimed to identify irrigation strategies that optimize water use while maintaining favorable growing conditions for apple production and providing a reliable agronomic background for varietal evaluation. Field experiments took place during 2016–2018 on mature Golden Delicious trees grafted on MM106 rootstock. Comparing four irrigation treatments included drip irrigation, sprinkling, combined drip–sprinkling irrigation (drip at air temperatures ≤25 °C and sprinkling at >25 °C), and surface furrow irrigation (control). During the experiments, the soil moisture maintenance in the root zone was within the optimal limit. The study recorded data on microclimatic parameters (air temperature and humidity), plant water-regime indicators (leaf water content, transpiration intensity, relative turgidity deficit), yield, fruit size, sugar content (°Brix), and irrigation water productivity. The highest apple fruit yield emerged in the combined irrigation (about 19.7 t ha⁻¹), followed by sprinkling and drip irrigation, while surface irrigation produced the lowest yield. Drip irrigation required the least water and resulted in the highest fruit sugar content, whereas surface irrigation showed the lowest water-use efficiency and fruit quality. Overall, combined irrigation proved the most effective method in hot, low-humidity environments, providing a balance between water savings, yield, and fruit quality.

Keywords: Irrigation methods, water productivity, apple fruit yield and quality, sugar content, microclimatic conditions, water regime of plants

Key findings: Combined drip-sprinkling irrigation most effectively mitigated heat and humidity stresses, resulting in the highest water productivity and fruit yield of the apple cultivar Golden Delicious under arid conditions. Drip irrigation minimized water use and produced fruits with the highest sugar content, while surface irrigation was the least efficient.