The Pears of New York. U. P. Hedrick
slow growth, when, possibly, it acts as a deterrent to blight, and certainly makes more certain thorough ripening of the new wood.
The double nature of pruning must be kept in mind whenever a pruning tool is taken in the pear-orchard. Fruit-trees are pruned to increase the quantity and quality of the crop—this is pruning proper; and to give the trees such form that they are easily managed in the orchard—this is training. Pruning tools are used first when the trees are set, and they should be used every year thereafter as long as the tree lives. The pruning at setting time is particularly important with the pear, since newly set pears are slow and uncertain in starting, and linger in growth for a year or two after going into the orchard. The pruning is much the same as with other trees, but must be done with a little greater care.
The top of the young plant must be pruned to enable the injured root-system to supply the remaining branches with water. The less the roots are injured, the less the top need be cut. Some cut back all of the branches; some remove whole branches and do not head back those that remain. The latter is the better plan for this reason: The top buds on branches are largest and develop first, and the newly set tree will grow best if it develops a large leaf-surface before hot dry weather sets in. Young trees usually have surplus branches; remove those not needed, leaving three, four, or rarely five to form the framework of the tree. A pear so pruned will start growth and acquire vigor more quickly than if all branches are cut back.
A choice must be made when planting as to whether the tree is to be low- or high-headed. The habit of growth of varieties differs so greatly that there can be no rule to determine how high the head of a tree should be started. One can generalize to this extent: The heads of varieties with spreading tops should be started higher than those having an upright or pyramidal top. Without question, the choice should be for a low-headed pear-tree. The trunks of pear-trees suffer terribly from blight and sun-scald. The less trunk and the more it is shaded by branches, the less the tree suffers from these two troubles. Also, low trees are more easily sprayed and pruned; the crop is more easily thinned and harvested; crop and tree are less subject to injury by frost; the top is more quickly formed; and a low-headed tree bears fruit soonest. By low-headed is meant a distance from the ground to the first limb of two feet.
Two shapes of tops are open to choice—the open-centered and the close-centered. In the open-centered, or vase-form top, the tree consists of a short trunk, surmounted by four or five main branches ascending obliquely. In the close-centered top, the trunk is continued above the lower branches and forms the center of the tree. The close-centered pear-tree produces more fruit and is most easily kept to its shape. No doubt it is best for most varieties. The open-centered tree, with its framework of several main branches, has the advantage when trees are attacked by blight, since if one or two branches are destroyed by the disease a part of the tree may still be saved. The head should never be formed by two central leaders forming a crotch, as the trunk is liable to split and ruin the tree.
For several years after planting, the pear needs to be pruned only to train the tree to the height of head determined upon and to form the top. Exceptions are the sorts which produce few branches and thus form straggling heads. This defect is overcome by cutting back some of the branches in the spring, an operation which increases the number of branches. A few other sorts, as Winter Nelis and White Doyenné, have drooping, twisting, wayward branches which can be trained into manageable shape only by cutting back or tying the branches in place. Pear-growers as a rule prune young trees too much. Over-pruning increases the growth of wood and leaf too greatly, and thus delays the fruiting of the plant. A good deal might be said about the use and abuse of heading-in pears—that is, cutting back the terminal growths from year to year. Dwarf pears must be headed-in severely to keep the trees down, but standard trees should be headed-in only to make the tops thicker and broader—a desirable procedure with some varieties.
Old trees often need to be pruned to increase their vigor. Such pruning is often spoken of as pruning for wood. When the tops of pear-trees have dead and dying wood, when the seasonal growth is short and slender, when the crops are small and the pears lack size, or when trees are weakened by disease, a healthy condition may oftentimes be restored by severely cutting back some branches and wholly removing others. In such pruning the following rules ought to be observed:
Weak-growing varieties are pruned heavily; strong-growing kinds, lightly.
Varieties which branch freely need little pruning; those having few and unbranching limbs should be pruned closely.
In cool, damp climates, trees produce much wood and need little pruning; in hot dry climates, growth is scant and trees need much pruning.
Rich, deep soils favor growth; trees in such soils should be pruned lightly. In light or shallow soils, trees produce few and short shoots; the pruning of trees on such soils should be severe.
A good deal is said about pruning for fruit. It is doubtful, however, whether unfruitful pear-trees can be made more fruitful by the pruning recommended for this purpose. When barrenness is caused by the production of wood and foliage at the expense of fruit-buds, as possibly sometimes happens, summer-pruning may check the over-production of growth and cause flower-buds to form. There seems to be no definite experiments to prove this theory in America, nor do pear-growers generally practice this kind of pruning which has been preached so long and so often. To follow the rules in this operation, summer-pruning should be done when the growth for the season has nearly ceased. If done earlier, the shoots cut back start again and the pruning has been useless. If done too late, there is too little time for the production of fruit-buds. In the unequable climate of this country it is most difficult to know when to prune in the summer to meet the requirements of the theory urged so strongly by European pomologists. A weighty objection to summer-pruning in America is that the wounds might and probably would become centers of infection for blight.
There is no attempt to give a full discussion of pruning in this text. Such details as making the cut, covering the wounds, pruning paraphernalia, filling cavities and the amount to prune, belong to texts on pruning. Perhaps two minor details important in growing pears should be mentioned. Suckers or water-sprouts form so freely on branches of pears that they often seriously devitalize the tree, and usually are centers of blight. They should therefore be removed promptly whenever and wherever found. The time to prune the pear is important. If the work is done too early in the winter, injury may result to the tissues near the wound from cold or from checking. If done late in the spring when sap is flowing, the wound becomes wet and sticky and is a suitable place for the growth of fungi and the blight bacterium.
The pear is as easily grafted as any other pome, and the operation is more certain and more often desirable than with any of the stone-fruits. Almost any method of grafting used with orchard fruits is successful with the pear. But the pear is not often grafted in this State after the tree has been set in the orchard. The great objection is that the vigorous growth made by grafts is nearly always nipped by blight. Possibly the lack of affinity between different varieties is more pronounced than with other pomes. The common European varieties cannot be inter-worked without experimental knowledge of how one variety will grow on another, and it is almost impossible to intergraft common varieties with the oriental hybrids. The temptation is strong in this State to graft such sorts as Bartlett and Seckel on Kieffer. This combination is seldom successful; nor, as a rule, can other European pears be grafted on Kieffer, although some growers have succeeded fairly well in growing Seckel on Kieffer.
Thinning the fruit is not a common practice in pear-growing in this State. There is no doubt but that much might be done to improve pears in both size and quality by thinning, for be it remembered that large size of fruit and high quality are usually correlated in pears. Thinning often saves the vigor of the tree, and it is often good orchard management to destroy insect- or disease-infected fruit by thinning. The objection is high cost. Most growers, however, find that it pays to thin. Thinning is usually done as soon as possible after the June drop. It is most difficult to tell, when thinning, what will prove superfluity at harvest. A skilled grower adjusts the size of the crop to the variety, the vigor of the tree, fertility and moisture in the ground, the season, and insects and fungi. Thinning should begin in the winter with the removal of what seem to be superfluous branches, for even at this time fruit-prospects for the ensuing season are fore-shadowed.