In a message dated 7/6/2004 7:33:09 AM Central Daylight Time, pbs-zonneveld@RULBIM.Leidenuniv.nl writes: > most > clones of vegetatively propagated plants have to be replaced by > new ones due to loss of vigour. > Hi, I have seen this idea before; it has sometimes been mentioned in regard to rose varieties too. For all I know, it may be correct. Does anyone have published data (scientific data) to support or refute the idea that clones generally lose vigor over time. Cordially, Joe, 90 F, humid,