Influence of SO4 and Rupestris du Lot (Monticola) Rootstocks on the Production of Tangra Dessert Vine Planting Material

The role of the vine rootstock and its correct selection is the main step in creating vine plantations to achieve a balance between vine growth, yield and grape quality. The studies in this direction are aimed at determining the most suitable rootstock for the different vine varieties, with the objective of their optimal development. In 2018–2021, the agrobiological parameters of vines of Tangra variety, grafted onto two rootstocks – SO4 (Berlandieri×Riparia selection Oppenheim 4) and Monticola (Rupestris du Lot), with different disposal of the root system and affecting the growth vigour and development of the vines, were studied in the Experimental nursery for grapevine rootings of IASS “Obratzov Chiflik”, Ruse, Bulgaria. The experiment was carried out in two variants, each in four replications with 50 grafted cuttings with drip irrigation and micro-jet irrigation in the first month after planting for rooting. The study aimed to recommend the most suitable rootstock for grafting Tangra dessert seedless variety to avoid adverse modification changes caused by it. Monticola rootstock was found to influence positively on the percentage of premium rooted vines, forming a better root system and inducing better growth and maturing of the increment in the production of vine planting material, compared to vines, grafted onto SO4 rootstock.