Performance of ‘Golden Delicious’, ‘Jonagold’, ‘Empire’, and ‘Rome Beauty’ Apple Trees on Five Rootstocks Over Ten Years in the 1990 NC-140 Cultivar/Rootstock Trial

Abstract

At 12 sites in the United States, trials were established in 1990 which included four apple ( MalusX domesticaBorkh.) cultivars (‘Smoothee Golden Delicious’, ‘Nicobel Jonagold’, ‘Empire’, and ‘Law Rome Beauty’) in all combinations on five rootstocks (M.9 EMLA, B.9, Mark, O.3, and M.26 EMLA). After ten growing seasons, rootstock and scion cultivar interacted significantly to affect trunk cross-sectional area (TCA), root suckering, yield efficiency, and fruit size but not survival or yield per tree. In all cases these statistically significant interactions contributed minimally to the variability among rootstocks and were relatively unimportant in determining tree performance. Comparing cultivars after 10 years, survival was greatest for ‘Empire’ and poorest for ‘Rome’. ‘Jonagold’ had the largest TCA, and ‘Empire’ and ‘Rome’ had the smallest. Root suckering occurred most prevalently with ‘Empire’. ‘Rome’ yielded the most, and ‘Jonagold’ and ‘Empire’ yielded the least. ‘Rome’ trees also were the most yield efficient, and ‘Jonagold’ trees were the least efficient. Largest fruit were ‘Rome’ and ‘Jonagold’. Comparing rootstock effects over 10 years, B.9 resulted in the greater tree survival than did O.3. M.9 EMLA, and Mark, and M.26 EMLA resulted in intermediate survival. Trees with the greatest TCA were on M.26 EMLA. Trees on M.9 EMLA and those on O.3 were similar and significantly smaller. Trees on B.9 and those on Mark were similar in size and the smallest in the trial. The greatest root suckering developed from B.9, Mark, and O.3, and the least came from M.26 EMLA. Trees on M.26 EMLA, O.3, and M.9 EMLA yielded similarly and significantly more than those on B.9 or Mark. The most yield efficient trees, however, were on B.9 and Mark, and the least were on M.26 EMLA. M.26 EMLA and M.9 EMLA resulted in the largest fruit size, and Mark resulted in the smallest.