In this report, methods of propagating resistant varieties,
including ¡¦Duke 7 ¡¦, ¡¦Duke 6 ¡¦, ¡¦G6 ¡¦, and ¡¦G22
¡¦, was compared. Among the scions of ¡¦Duke 7 ¡¦, ¡¦Duke 6
¡¦, ¡¦G6 ¡¦ and ¡¦G22 ¡¦, grafted to seedling stocks from
unknown parents, scions of ¡¦Duke 7 ¡¦ had highest percent of
successful graft unions of 71.0%. After etiolated, growing shoots
had 50% survival in ¡¦Duke 7 ¡¦. Among air layered shoots,
which had been etiolated and girdled before, rooting shoot
percent in ¡¦Duke 7 ¡¦and ¡¦Duke 6 ¡¦both had 50%, while that
in ¡¦G22 ¡¦only 0%. In general, scions of ¡¦Duke 7 ¡¦ and
¡¦G6 ¡¦varieties could had adventitious root formation from
stem surface of shoots above graft union in six months after
layered by using this method. After following six months new
plant growing on its own roots could be got by cutting just below
the adventitious root initiating part of the rooting shoot.
Rooting plants could grow vigorously after potted in plastic
pots. Among tested varieties, ¡¦Duke 7 ¡¦ had highest
propagation efficiency of 17.8% with this method.