The Northern Spy apple as a rootstock
Ann Rept Ii Suppl East Mailing Res Sta 14(15): 44-50
The growth and early cropping of the variety Grenadier is compared when budded on Northern Spy, and semi-dwarfing, vigorus and very vigorous layered rootstocks. Under East Mailing conditions, Spy would be classed as a semi-dwarfing rootstock, of the Doucin (Mailing No. II) Group, but comparing unfavorably with it in early cropping.