Particular Fruit Tree Pests and Diseases
When a tree is found to be making too much growth, with the result that it does not fruit properly, there are two ways of checking it and bringing it into bearing. The first is root pruning-this should be carried out early in the winter when the leaves have fallen. A trench 2 feet wide and 3 feet deep is dug out 3 feet away from the trunk and all roots met with during this operation cut off cleanly.
Though it is possible to do this all round the tree in any one year it is usually considered kinder to the tree (and. incidentally to the gardener!) if a half-circle is dug out on one side of the tree one winter and the remaining half-circle dug out the following winter.
The woolly aphis, or American Blight, which forms masses of cotton-wool-like substance on the twigs or trunk, should be painted with neat liquid duds the moment it is seen. The tar-oil wash Mortegg, when used in December, helps to keep this pest in check. While if one uses B.H.C. (double strength) before blossoming better results are achieved.
By ringing, the compost fruit grower does not stop the flow of mineral sap upwards to the parts above the ring, but he does keep the elaborated sap up in the branches because this would have passed down the bark surface. By altering the ratio between the crude sap and what may be called the manufactured plant foods, you ensure that fruit buds are formed and growth restricted.
Another method of encouraging the production of fruit buds is the shoot-circling method. The laterals or one-year-old side growths, instead of being pruned in the summer or winter are left at full length and then are tied down with string to form an almost complete circle.
The result of this circling or curving is that fruit buds are produced because the sap is checked and the following season the circled shoot may be pruned back to just above a suitable fruit bud. I found Ellison’s Orange, Charles Ross, Tydeman’s Early Worcester, Sunset and Jewel to do particularly well under this system.
