Evaluation of pear rootstocks selections

European pear ( Pyrus communis L.) is in Italy predominantly grown on clonal quince ( Cydonia oblonga Mill.) rootstocks. However, this grafting combination shows several problems including poor graft compatibility, susceptibility to lime-induced iron chlorosis and pear decline, which are normally not observed when P. communis is used as rootstock. Since 1979, the University of Bologna (Italy) has undertaken a breeding programme to obtain new clonal pear rootstocks and in 1996 two clones (Fox 11 and Fox 16) were released. Recently, the programme focused on clones with a marked size-controlling aptitude and high yield efficiency. In 2002 and 2004 two experimental trials were arranged to evaluate the performances of cultivars 'Abbe Fetel', 'Conference' and 'Bartlett' grafted on eight pear clones of Bologna University (A74, C19, C91, D46, D50, E82, E105 and Fox 9), Farold 40 Daygon and quinces BA29, MC and Sydo. Fox 9 showed a slightly higher vigor and yield performance compared to quince BA29, and good fruit quality. In addition, Fox 9 showed high environmental adaptibility, good suitability to be micropropagated and high graft compatibility with the tested cultivars. Based on these findings, in 2008 Fox 9 was released as a new rootstock for P. communis and the application for community plant variety rights (EU patent) was lodged. Among the other pear selections tested, D46 and D50 induced good yield but also the highest vigour, while C91 was interesting for the moderate growth