Reduced Irrigation Improves Water-Use Efficiency of Mediterranean Greenhouse Cherry Tomato
Water scarcity is a critical constraint for agricultural production, particularly in Mediterranean regions, since it is a key stressor directly affecting plant growth, yield, and fruit quality in vegetables. Among others, cherry tomato (Solanum lycopersicum var. cerasiforme) represents a high-value crop with increasing global importance due to its economic, nutritional, and commercial attributes. The objective of this research is to evaluate the seasonal (autumn and spring) effects of reduced irrigation volumes relative to commercial practice on the yield, fruit quality, water-use efficiency (WUE), and physiological responses of cherry tomato plants grown under greenhouse conditions. Plants were irrigated according to growers’ standard practices (100%), as well as 75% and 50% of that water volume, throughout a cultivation cycle of 11 months (August to July). Results indicate strong seasonal variation in quality and physiological parameters (+35.3% single fruit fresh weight and +34.2% flesh firmness, but −68.2% total phenolic compounds content and −38.5% total antioxidant capacity during late autumn assessment). A 50% irrigation level reduction significantly improved water-use efficiency (+82.7%), but reduced single fruit fresh weight (−22.9%) and showed a declining trend in total yield. We conclude that local irrigation practices should be reconsidered in regions highly affected by water scarcity and suggest that the 75% treatment has a practical potential.