COMPARISON OF THE VIRAL TRANSMISSION EFFI CIENCY OF DIFFERENT GRAFTING TECHNIQUES ON GRAPEVINES

With the objective of screening a great number of grapevine varieties for their resistance to virus diseases, we looked for the most appropr iate technique of inoculation. As the mechanical inoculation of a viru s to the grapevine succeeds only under special conditions, we compared different grafting techniques: dormant grafting and green grafting, t he last with and without previously rooted rootstock. For each of thes e three methods, the inoculum was used as the stock on one hand, as th e scion on the other hand. This study proved that the dormant grafting technique using the inoculum as the rootstock is the most efficient t echnique. Nevertheless, good results were obtained by using the green grafting technique without previously rooting the rootstock, the inocu lum being also used as the rootstock. As the green grafting method doe sn't require a great area, is not time-consuming and can be performed throughout the year, it seems therefore to be a very convenient method of inoculating a great number of varieties.