Field Performance of ‘Summerland Red Mclntosh,’ ‘MacSpur Mclntosh,’ ‘Empire’ and ‘Idared’ On Six Rootstocks

Abstract

Under commercial orchard practice ‘Idared’ yields were highest for the combined full crop years of 1985 and 1988. ‘Empire,’ ‘Summerland Red (SR) McIntosh’ and ‘MacSpur (MS) McIntosh’ produced less respectively. In 1988 ‘SR McIntosh’ and ‘Idared’ had highest yields. The ‘SR McIntosh’ grew the largest; the three other cultivars were smaller and similar in size. Efficiency and crop load was greatest for ‘Empire’ followed by ‘Idared,’ ‘SR McIntosh,’ and ‘MS McIntosh.’ Irrespective of the cultivar the rootstocks Alnarp 2 (A 2) and Beautiful Arcade seedlings (BA) induced the greatest yield, followed, in decreasing order of magnitude by rootstocks M.25, MM.106, MM.111, and M.7. The largest trees were on BA, while M.25, A 2, MM.111, MM.106, and M.7 were smaller respectively. Yield efficiency and crop load was highest for MM.106 and A 2 and lowest for M.7, and MM.111. Fruit quality was influenced by the cultivar and not by the rootstock. Over the two years, ‘Idared’ had the highest percent in the large size category of 70 mm, the least for the small category of 57-64mm, and the heaviest average weight. ‘Empire’ had the fewest in the large category, the highest in the small category and the lightest weight. Red color was highest for ‘MS McIntosh’ and the least for ‘SR McIntosh.’