A certain period of cold is needed to break bud dormancy for almost all woody species. A pre-forcing bleach soak has been demonstrated to at least partially replace this requirement (Yang and Read, 1989). Therefore, new softwood growth can be produced in the off-season. Such supple softwood growth is excellent material to be used either as explants for in vitro culture, or as cuttings for macropropagation of woody species. Further studies on pre-forcing bleach soaks were conducted to investigate optimum concentration and duration of soak, and to find the most suitable depth of bleach solution soak, in order to maximize the breaking of bud dormancy. Optimum bud break was obtained by soaking the basal 1/3 of dormant stems in 10% bleach solution for 10 minutes prior to forcing. Soaking dormant woody stems in alcohol solutions prior to placing stems in the forcing solution was also studied. The alcohol soak had negative effects on bud break of spirea, although it showed positive effects for lilac and privet.
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