Influence of irrigation on the growth and quality of grapevine propagation material

Efficient water management is essential in grapevine nurseries, where irrigation strongly influences the morphological quality and the suitability of propagation material for successful vineyard establishment. This study evaluated the impact of two irrigation regimes on grafted grapevine seedlings produced under protected nursery conditions in 2025. Four table-grape cultivars (‘Argessis’, ‘Memory’, ‘Norocel’, and ‘Ștefănești’) grafted onto SO4-4 rootstock were grown under irrigation levels corresponding to 100% and 75% of the Active Soil Moisture Interval (ASMI). Morphological characteristics, including leaf area, main shoot length and diameter, number of roots ≥ 2 mm, main root length, and maximum root diameter, were assessed to evaluate shoot vigor and root morphological characteristics. Water use efficiency (WUE) was also determined to characterize the technological performance of each irrigation regime. The reduced irrigation level (75% ASMI) improved the morphological characteristics of both shoots and roots in most cultivars, increased the proportion of first-quality vines, and resulted in substantially higher WUE. The results obtained have confirmed that a 75% ASMI regime can improve water-use efficiency while sustaining high morphological quality, highlighting its potential as an efficient and sustainable irrigation strategy for nurseries.