Interactive Effects of Irrigation Depth and Fertilization Level on Graft Establishment, Nursery Survival, and Water Productivity in Peach Nursery Production

Efficient irrigation management is critical for improving irrigation water productivity and producing high-quality planting material in fruit tree nurseries. This study evaluated the effects of irrigation and fertilization on peach nursery performance through a two-year field experiment conducted in a commercial nursery in northwestern Romania. The experiment included two cultivars (‘Redhaven’ and ‘Cresthaven’), four irrigation depths (0, 10, 20, and 30 mm for each irrigation event), and two fertilization levels (N0P0K0 and N8P8K8) arranged in a factorial design. Irrigation significantly improved graft establishment and nursery survival compared to rainfed conditions. Optimal irrigation (20 mm) resulted in the highest nursery survival and provided the best balance between plant productivity and irrigation water productivity. Higher irrigation inputs increased total water consumption but reduced irrigation water productivity. Regression analysis revealed nonlinear relationships between water consumption and nursery performance, indicating diminishing returns at higher irrigation levels. The results suggest that moderate irrigation can enhance nursery productivity while improving water use efficiency. These findings provide practical guidance for optimizing irrigation strategies in commercial peach nursery systems.