Opportunities for Reducing the Time Necessary to Obtain Trees with Interstocks in Pear Trees

Using quince as a rootstock is restricted for some pear tree cultivars by their low compatibility or incompatibility with the quince rootstock. To avoid this phenomenon it is necessary to use an interstock, but this method adds one extra year to the time required to obtain grafted trees. To reduce the time required to obtain trees with an interstock, from 3 years to 2 years, various grafting methods were studied in this paper. Methods tested were: chip budding with double shield buds previously non-callused or callused; and detached branches grafted with buds previously non-callused or callused. Grafting success depended upon the grafting method being used. The best results were obtained when applying at the beginning the methods using chip budding with double callused shield buds (58.7%. of trees produced complied with the STAS standard, obtained on field II). When grafting and graft callusing on the interstock are made about 15 days before grafting on the rootstock, it gives a substantial increase in crop volume, as compared to the methods previously used involving non-callusing.