Performance of Golden Delicious cv. 'Smoothee' on dwarfing rootstocks and interstems in a hot, humid climate

This study was conducted to determine performance of Golden Delicious cv 'S moothee' on several dwarfing rootstocks and interstems in the long growing season of the Southeastern U.S. Tree mortality was high for the dwarfing ro otstocks and interstems due to flooding stress the year the trees were plan ted, an occasional problem in this region. The semidwarfing rootstocks with and without interstems did not differ in survival. Dwarfing interstems on semidwarfing rootstocks and dwarfing rootstocks without interstems provided adequate growth control, whereas semidwarfing rootstocks without interstem s did not. Cropload density was highest with any dwarfing interstem on MM.1 06 EMLA and M.7A rootstocks. Yield was best on M.9 EMLA and M.26 EMLA roots tocks with no interstems. Yield efficiency was highest for M.27 EMLA and M. 9 EMLA rootstocks and next with any dwarfing interstem on MM.106 EMLA and M M.111 EMLA rootstock. Mark and M.27 EMLA are not suitable in this region be cause of small fruit size in this experiment. Firmness and soluble solids w ere not strongly affected by treatment. The best performing trees were M.9 EMLA, M.26 EMLA, M.7A and MM.106 EMLA rootstocks without interstems, and an y interstem on either M.7A or MM.106 EMLA rootstock. The interstems provide d sufficient growth control whereas the semidwarfing rootstocks without int erstems did not.