Nurseries across the country are propagating several Geneva rootstocks. A million G.11 rootstocks should be available by 2013. Substantial numbers of disease-resistant Geneva apple rootstocks will be ­available from nurseries in the next few years.    U.S. nurseries will have 250,000 G.11 rootstocks in stool beds this year and should have 500,000 by 2012. The quantity should double again to a million in 2013, according to Dr. Terence Robinson, horticulturist at Cornell University. Fewer G.41 rootstocks will be available because of difficulties nurseries had in propagating that rootstock in stool beds at first. It is now being propagated through tissue culture, […]