Level of affi nity between grapevine rootstock and Vitis vinifera as scion, quality of reproductive materials and technological actions in grapevine rootstock production process determine success in grapevine rootstock production in large extent. Practical training showed that difference in level of compatibility between grapevine rootstock and grafted Vitis vinifera cultivars are existing. Direct effects of these differences are unequal yield of fi rst class grafted
grapevine rootlings. In this paper, level of compatibility in nursery between clones of cv. Chardonnay BCL 75, VCR4 and cv. Merlot R18, MCL 519 and grapevine rootstocks Kober 5BB (Vitis berlandieri x V. riparia), SO4 (V. berlandieri x V. riparia) and 41B (Chasselas x V.berlandieri) were investigated. The trial was conducted in commercial grapevine nursery located in Velika Drenova, Serbia. As an index of compatibility, grade of high quality grapevine grafted
rootlings, dry matter in mature shoots and root system development were used. Grafting was done by `tongue grafting` indoor technique. Stratifi cation was done in sand, on temperature of the stratifi cation material of 26-28oC, and humidity of around 90%. Grafted cuttings were waxed twice: before stratifi cation, and before planting in the nursery. Grafted rootlings were classed in two classes according to regulations of quality, (Yugoslav Offi cial Register, 26/79). Grafted
rootlings that did not satisfi ed standard criteria were discarded. Both clones of cv. Chardonnay gave the highest percentage of I class grafted rootlings on grapevine rootstock 41B: clone BCL 75 – 60% and clone VCR4 – 61%. In the same combination, those grapevine grafted rootlings had the highest weight of the root system. Lower percentage of obtained I class grafted rootlings was established on rootstock Kober 5BB, while statistically signifi cantly lower yields were obtained on grapevine rootstock SO4: clone BCL75 – 43% and clone VCR4 – 48%. Dry matter content in mature shoots is showing good maturity of shoots in cv. Chardonnay in all experiment combinations and varies from 53% up to 54%. Clones of Merlot, in this investigation, showed the highest level of compatibility with rootstock Kober 5BB. Percentage of I class grafted rootlings on this rootstock for clone R18 was 66%, and for clone MCL 519 was 62%. In the same experiment combination the highest root weight was established as well. The low degree of grafting compatibility was obtained by grafting Merlot clones on rootstock SO4, that is shown by signifi cantly lower percentage of produced I class grafted rootlings in relation to obtained values by grafting on other examined grapevine rootstocks (clone R18/SO4 – 51%; clone MCL519/SO4 – 50%).
