The effect that indolebutyric acid (IBA) and position of cane segment have on the rooting of cuttings from grapevine rootstocks and from Cabernet franc (Vitis vinifera L.) under conditions of a hydroponic culture system

The present study aimed at determining the effect of indolebutyric acid (IBA) and of the part of cane from which the cuttings were taken on the rooting ability of three rootstocks and of a grapevine variety using a hydroponic system employing water as the culture medium. Under hydroponic conditions, three different auxin treatments (control water, 120 and 250 ppm IBA) were applied on the three rootstocks, namely 1103 Paulsen, SO4, Dog Ridge and cv Cabernet franc (Vitis vinifera L.). The treatments were applied annually for a period of two (2) years and, more specifically, in 2014 and 2015, using a completely randomized design. The cuttings were collected from the Experimental Vineyard, Laboratory of Viticulture, Agricultural University of Athens. The study continued by evaluating the effect of that three factors, rootstock/variety, cane part donating the cuttings, and IBA concentration had on the following: percentage of callogenesis, percentage of rhizogenesis, average diameter of roots, average number of roots per cutting, total surface of roots, and total length of roots. The results of the experiment revealed that treatment with 250 ppm IBA and cuttings coming from the middle part of the cane yielded the highest rhizogenesis percentages. At the same time, the highest callogenesis percentage was observed in the basal cuttings of rootstock 1103 P that underwent the same treatment. Following the 120 ppm IBA treatment, the basal cuttings of rootstock Dog Ridge presented the highest average number of roots. Under the 250 ppm IBA treatment, the basal, middle and middle cuttings of the Dog Ridge rootstock respectively presented the highest average diameter, surface, and length of roots. The experiment led to the conclusion that, under hydroponic conditions and when treated in low IBA concentrations, the grapevine variety and the rootstocks under study can give rooting results which are quite satisfactory. Based on those results, a hydroponic system employing water as its culture medium may prove practical and economical when it comes to vine propagation.