Performance of Golden Delicious cv. ‘Smoothee’ on Dwarfing Rootstocks and Interstems in a Hot, Humid Climate

Abstract

This study was conducted to determine performance of Golden Delicious cv ‘Smoothee’ on several dwarfing rootstocks and interstems in the long growing season of the Southeastern U.S. Tree mortality was high for the dwarfing rootstocks and interstems due to flooding stress the year the trees were planted, 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 interstems did not. Cropload density was highest with any dwarfing interstem on MM.106 EMLA and M.7A rootstocks. Yield was best on M.9 EMLA and M.26 EMLA rootstocks 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 MM.111 EMLA rootstock. Mark and M.27 EMLA are not suitable in this region because of small fruit size in this experiment. Firmness and soluble solids were 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 any interstem on either M.7A or MM.106 EMLA rootstock. The interstems provided sufficient growth control whereas the semidwarfing rootstocks without interstems did not.