The orchard establishment, growth and precocity of four micropropagated apple scion cultivars

SummarySelf-rooted trees of Cox’s Orange Pippin, James Grieve, Greensleeves and Golden Delicious apple cvs, produced by micropropagation in vitro in 1978, were planted in April 1979 in a field trial to compare them with trees of the same cultivars produced conventionally by budding onto M.9 and MM. 106 rootstocks in 1977. The micropropagated trees were much smaller at planting than the (older) conventional trees, and although they all were difficult to establish and grew slowly in the year after planting their subsequent performance varied greatly between cultivars. Greensleeves on its own roots was less vigorous (up to five years of age) than Greensleeves on MM. 106 although it was somewhat more vigorous than Greensleeves on M.9. It flowered in the year after planting (1980), and in the subsequent years produced as many or more flowers and fruits per unit length of branch as did the Greensleeves on M.9 and MM. 106. James Grieve on its own roots was much more vigorous in absolute terms and relative to its...