In 1984 trees of `Starkspur Supreme Delicious' apple (Malus domestica, Borkh) on 16 rootstocks were planted at 32 sites In Morth America according to guidelines established for cooperative testing by the North Central Regional Cooperative Project (NC--140). Tree loss and root suckering in the Maine planting have been low, similar to that of other sites. Tree size in Maine is smallest amoung all sites after eight seasons. Trees on Budagovsky 9 (B.9) rootstock were the most precocious, producing significantly higher flower numbers and yield in the third year. Other precocious rootstocks in this planting included C.6, M.26EMLA, M.7EMLA and P.l. After eight years, B.9, C.6 and M.26EMLA were the most productive amoung the dwarf trees. P.l and M.7EMLA were the most productive amoung the more vigorous stocks. Heavy croping trees on dwarf rootstocks leaned more due to hurricane winds than larger better anchored trees which lost a larger proportion of their crop. B.9, C.6 and P.1 may have potential as rootstocks for commercial apple orchards in New England.
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