ISHS Acta Horticulturae 146: International Workshop on Controlling Vigor in Fruit Trees
THE RESPONSE OF TWO APPLE CULTIVARS TO DIFFERENT COMBINATIONS OF DWARFING ROOTSTOCKS, TREE DENSITIES AND TRAINING SYSTEMS |
| Author: | R. L. Granger |
| Abstract:
Test plots of the apple scion cultivars Spartan and McIntosh were established at the experimental farm of Frelighsburg, Quebec, in 1976. The Spartan was grafted on Malling 9 (M. 9), Malling 26 (M. 26), Ottawa 3 (Ott. 3) and Malling 7 (M. 7) while the McIntosh was grafted on M. 26 and M. 7. These trees were submitted to 4 training systems: the freestanding Christmas tree, the slender bell (a version of the slender spindle), the Van Roechoudt palmette and the oblique palmette. For the Christmas tree and the slender bell systems, the French vertical axis type of pruning was used. The densities were 740 (low) and 1480 (medium) trees per hectare for the Christmas tree, 1480 and 2960 (high) for the slender bell, 740 and 1480 for the Van Roechoudt and 1480 and 2960 for the oblique palmette system. The trees were grown in herbicide treated strips and watered by trickle irrigation. The severe winter of 1980–1981 and the apple tree damage caused by grazing deers were the limiting factors responsible for lowering the production of the experimental trees. The slender bell system at 2960 trees/ha gave the highest yield. The Van Roechoudt system at 740 trees/ha yielded the lowest crop of apples. The most prolific scion/rootstock combination was Spartan/Ott. 3 and the one which yielded the least was Spartan/M. 7. Spartan/M. 26 was the second most precocious and productive. The highest percentage of small apples was found with the Spartan/M. 9 combinations while the highest percentage of large apples appeared in McIntosh/M. 26 and McIntosh/M. 7. The McIntosh/M. 7 scion/rootstock combination was the most vigorous and the Spartan/M. 9 along with Spartan/Ott. 3 were the least vigorous ones. So far, our findings lead to the conclusion that for early cropping, total yielding, compactness, acceptability of fruit size and winter hardiness, the slender bell system at high or medium density with Spartan/Ott. 3 or Spartan/M. 26 are the most profitable proposal under the climatic and soil conditions of the Frelighsburg area. | |
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