Effects of Irrigation Depth on Soil Water Availability and Vegetative Growth of Nursery- Grown Apricot Plants

For fruit trees produced in nurseries, effective irrigation management is essential, especially in climates that are becoming more unpredictable and exacerbate seasonal soil moisture deficiencies. This study assessed the effects of varying irrigation depth on the vegetative growth and soil water availability of apricot (Prunus armeniaca L.) nursery plants grown in an open-field system in northwest Romania over the 2024 growing season. Four irrigation depths (0, 10, 20, and 30 mm each irrigation event) were applied to two commercially significant cultivars (Excelsior and Favorit) that were grafted onto Prunus cerasifera rootstock. Tensiometers were used as indicators of relative soil water availability to track soil moisture dynamics in the 0–30 cm root zone, and total branch length was used as an integrative growth parameter to evaluate vegetative performance. While controlled irrigation reduced soil drying in a depth-dependent way, seasonal soil moisture indicators demonstrated significant depletion under rainfed settings during times of high atmospheric demand. In all cultivars, increasing irrigation depth was linked to increased cumulative vegetative growth; however, responses varied by genotype in terms of both magnitude and stability. Higher irrigation depths encouraged more vegetative growth with falling marginal returns, whereas moderate irrigation depths supported steady shoot development. These results highlight cultivar-specific sensitivity to soil moisture conditions and show that irrigation depth significantly affects soil water availability and nursery-stage vegetative growth of apricot plants. The results shed light on how irrigation depth influences early plant-water interactions and vegetative development in nursery-grown apricot plants under varying environmental circumstances.