Performance of ‘Golden Delicious’ Apple on 23 Rootstocks at 12 Locations: A Five-Year Summary of the 2003 NC-140 Dwarf Rootstock Trial

Abstract

In 2003, an orchard trial of apple [ Malus× sylvestris(L.) var. domestica(Bork.) Mansf.] dwarf rootstocks was established at 12 locations in Canada, Mexico, and the United States using ‘Golden Delicious’ as the scion cultivar. A core group of 11 rootstocks was planted at all locations. The four rootstocks included as industry standards were Malling 26 EMLA (M.26 EMLA), Budagovski 9 (B.9), M.9 Pajam2, and M.9 NAKBT337. The other seven rootstocks included selections from Russia (B), Cornell-Geneva (CG and G), Czech Republic (J-TE), and Germany (Pi Au); these included B.62396, CG.3041 [Geneva® 41], CG.5935 [Geneva®935], G.16, J-TE-H, and Pi Au56-83, and Pi Au51-4. Some locations also received two additional CG rootstocks, seven Japanese (JM) rootstocks, J-TE-G, or two Pi Au rootstocks. After five years, trees on J-TE-G were similar in size to B.9; trees on B.62396 and CG.3041 were similar in size to M.9 NAKBT337; trees on CG.5935, G.16, J-TE-H and M.9 Pajam2 were similar in size to M.26; and trees on Pi Au56-83, Pi Au51-4, Pi Au36-2 and JM.2 were larger than M.26 EMLA. For the first time in an NC-140 rootstock trial, several rootstocks have higher yield efficiency than M.26 EMLA and M.9 NAKBT337. Promising new rootstocks with very high yield efficiency included CG.5935, CG.3041, CG.5179 and J-TE-G.