Book V. OPERATIONS WITH PLANTS. 513 



3157. Splitting is an operation generally performed on roots of trees remaining in the 

 soil for the purpose of facilitating their eradication. The wedge, in its simplest form, 

 and of iron, is driven in by a hammer or mallet, till it produces fracture and separation, 

 when the parts are removed as detached, &c. 



3158. Pruning, or the amputation of part of a plant with the knife, or other instru- 

 ment, is practised for various purposes, but chiefly on trees, and more especially on those 

 of the fruit-bearing kinds. Of two adjoining and equal-sized branches of the same tree, 

 if the one be cut off, that remaining will profit by the sap which would have nourished 

 the other, and both the leaves and the fruits which it may produce will exceed their 

 natural size. If part of a branch be cut off which would have carried a number of fruits, 

 those which remain will set, or fix, better, and become larger. On the observation of 

 these facts is founded the whole theory of pruning ; which, though, like many other 

 practices of culture, it cannot be said to exist very obviously in nature, is yet the nio-.t 

 essential of all operations for the culture of fruit produced on trees. 



3159. The objects of pruning maybe reduced to the following: promoting growth and bulk ; lessening 

 bulk ; modifying form ; adjusting "the stem and branches to the roots ; renewal of decayed plants or trees ; 

 and removal or cure of diseases. 



3160. Pruning for promoting the growth cmd bulk of a tree is the simplest object of pruning, and is that 

 species which is chiefly employed by nursery-men with young trees of every description. The art is to cut 

 oft' all the weak lateral shoots, that the portion of sap destined for their nourishment may be thrown into 

 the strong ones. In some cases, besides cutting off" the weak shoots, the strong ones are shortened, in order 

 to produce three or four shoots instead of one. In general, mere bulk being the object, upright shoots are 

 encouraged rather than lateral ones ; except in the case of trees trained on walls, where shoots are 

 encouraged at all angles, from the horizontal to the perpendicular, but more especially at the medium 

 of 45 degrees. In old trees, this object is greatly promoted by the removal, with the proper instruments, 

 of the dead outer bark. 



3161. Pruning for lessening the bulk of the tree is also chiefly confined to nursery practice, as necessary 

 to keep unsold trees portable. It consists in little more than what is technically called heading down ; 

 that is, cutting off the leading shoots within an inch or two of the main stem, leaving, in some cases, some 

 of the lower lateral shoots. Care is taken to cut to a leaf bud, and to choose such from among the side, 

 upper, or under buds of the shoot, as the succeeding year's shoots may be wanted, in radiated lines from 

 the stem, or in oblique lines in some places to fill up vacancies. It is evident that this unnatural operation 

 persisted in for a few years must render the tree knotty and unsightly; and in stone-fruits, at least, it is 

 apt to generate canker and gum. 



3162. Pruning for modifying the form of the tree embraces the management of the plant from the time 

 of its propagation. In rearing trees planted for timber, it is desirable to throw the timber produced, 

 as much as possible, into long compact masses; and hence pruning is employed to remove the side 

 branches, and encourage the growth of the bole or stem. Where this operation is begun when the trees 

 are young, it is easily performed every two or three years, and the progress of the trees under it is most 

 satisfactory ; when, however, it is delayed till they have attained a timber size, it is, in all cases, much 

 less conducive to the desired end, and sometimes may prove injurious. It is safer, in such cases, to shorten 

 or lessen the size of lateral branches, rather than to cut them oft' close by the stem, as the large wounds 

 produced by the latter practice either do not cicatrize at all, or not till the central part is rotten, and has 

 contaminated the timber of the trunk. In all cases, a moderate number of small branches, to be taken oft" 

 as they grow large, are to be left on the trunk, to facilitate the circulation of the sap and juices. Where 

 timber-trees are planted for shelter or shade, unless intermixed with shrubs or copse, it is evident pruning 

 must be directed to clothing them from the summit to the ground with side branches. In avenues, and 

 hedgerow trees, it is generally desirable that the lowest branches should be a considerable distance from 

 the ground; in trees intended to conceal objects, as many branches should be left as possible; and in 

 others, which conceal distant objects desired to be seen, or injure or conceal near objects, the form must 

 be modified accordingly. In all these cases, the superfluous parts are to be cut oft' with a clean section, 

 near a bud or shoot if a branch is shortened, or close to the trunk if it is entirely removed ; the object 

 being to facilitate cicatrization. 



3163. Pruning for adjusting the stem and branches to the roots is almost solely applicable to transplanted 

 trees, in which it is an essential operation, and should be performed in general in the interval between 

 removal and replanting, when the plant is entirely out of the ground. Supposing only the extremities of 

 the fibres broken off, as is the case with very small plants and seedlings, then no part of the top will 

 require to be removed ; but if the roots have been broken or bruised in any of their main branches or 

 ramifications, then the pruner, estimating the quantity of root of which the plant is deprived by the 

 sections of fracture and other circuuist.tnces, peculiar and general, will be able to form a notion of what 

 was the bulk of the whole roots before the tree was disturbed. Then he may state the question of lessen- 

 ing the top to adjust it to the roots, thus: — as the whole quantity of roots which the tree had before 

 removal is to the whole quantity of branches which it now has, so is the quantity of roots which it now 

 has to the quantity of top which it ought to have. In selecting the shoots to be removed, regard must be 

 had to the ultimate character the tree is to assume, whether a standard, or trained fruit-tree, or orna- 

 mental bush. In general, bearing-wood and weak shoots should be removed, and the stronger lateral and 

 upright shoots, with leaf or shoot-eyes, left. 



3164. Pruning for renewal of the head is performed by cutting over the stem a little way, say its own 

 thickness above the collar, or the surface of the ground. This practice applies to old ozier-beds, coppice 

 woods, and to young forest-trees. Sometimes also it is performed on old or ill-thriving fruit-trees which 

 are headed down to the top of their stems. This operation is performed with the saw, and better after 

 scarification, as in cutting oft'the broken limb of an animal. The live section should be smoothed with 

 the chisel or knife, covered with the bark, and coated over with grafting-clay, or any convenient ((im- 

 position, which will resist drought and rain for a year. Those who are advocates for pruning when the 

 sap is dormant, will not of course be able to perforin the operation of scarification, 3nd covering the section 

 with bark. 



3165. Pruning for curing diseases has acquired much celebrity since the time of Forsyth, whose 

 amputations and scarifications for the canker, together with the plaster or composition which he 

 employed to protect the wounds from air, are treated of at large in his Treatise on Print-Trees. Ahrost 

 all vegetable diseases either have their origin in the weakness of the individual, or induce a degree of 

 weakness; hence to amputate apart of a diseased tree, is to strengthen the remaining part, because the 

 roots remaining of the same force, the same quantity of sap will be thrown upwards as when the head and 

 branches were entire. If the disease is constitutional, or in the system, this practice may probably, in 

 some cases, communicate to the tree so much strength as to enable it to throw it oft'; it it be local, the 

 ainputation of the part will at once remove the disease, and strengthen the tree. 



3166. Mowing is the operation of cutting down corn, grass, and other herbage crops, 



with the scythe. It requires great force in the operator, and also a twisting motion of 



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