RESISTANCE OF GRAPEVINE ROOTSTOCKS TO XIPHINEMA INDEX

M., Summary. The resistance of gral?ev~ne roo~s~ocks t? Xiphinema index fr°1!l four popula~ions (Italy, C~ifornia, I~rael and France) .was tested in pot experiments. The results indicate Vttzs candtcans as a source of resistance to X. tndex and connrm the resistance of Dog Ridge to the Californian pop~ation as :-veli as to the other p,?pula.tions tested. Differences in the. reaction to t?e roots~ocks were evident between the X. index populations, particularly that tram Callforrua, and these need to be taken into account in breeding programmes.