The second way of propagating by truncheons is in lengths of 1-3 ft., which are perhaps preferable to the others. They are out neatly, without any bruises or ragged edges, in which moisture might lodge and do mischief. They are planted horizontally, 4-5 iu. below the surface, the soil being fine, and kept moderately moist. This system may be adopted also for planting In permanent situations, but is better suited for nursery planting, as the soil requires careful prepara tion, and two plants may start from the same truncheon. In 2 years, the trees will be 4-6 ft. high, with stems 1-2 in. thick, according to the kind; these are fit for planting out, and will make strong scions for grafting seedling-plants. These latter will have been growing meanwhile. This short-truncheon system is especially recommended in hot dry climates, such as Queensland.
By Uovoli.—Upon the bark, especially of the upper roots, of the olive, are formed numbers of small " knaurs " or embryo buds, termed uovoii by the Italians. These are easily detached by a sharp penknife, eare beiug taken not to injure the tree. The latter must not be less than 10 years old when subjected to this treatment, as it must be mature, deep-rooted, and strong. When removed, the knots are planted like bulbs.
Cultivation.—The importance of thorough drainage has been already pointed out ; and the intending cultivator, bearing this well in mind, will understand that the digging of holes is not to imply that the intervals are to be left without being broken up. Where a depth of 4 ft. is used, it would be impossible, without artificial drainage, to prevent the wet from hanging about the roots of the trees, unless the soil were naturally deep and very porous. It must he remembered that one object in the cultivation of the olive is that the slopes of hills whose soil is unsuited for general cultivation may be utilized. In these situations, any considerable depth of soil will not be found, and 24 in. may be the maximum depth attainable. If this be the case, holes will have no advan tage in point of economy over continuous trenching, say to the width of 8-10 ft., with the additional facilities for drainage afforded by the latter mode. While such trenches will give sufficient room for the health of the trees, these will still benefit by the breaking up, at some subsequent period, of the intervening spaces, either by the hoe or plough.
Cultivation between the trees should be practised with caution. There is no mistake so great as to suppose that economy is gained by taking out crops from between the trees, unless it is quite certain that the latter are not being robbed of light, air, or nutriment. When the trees are quite young, and cover little space, a shallow-rooted crop may safely be taken off, provided that even then the seed is not allowed to fall within 5 ft. each way of the trees. If this be doni3 for a year
oretwo, it is as much as can be ventured ; after this, any crop raised, in place of being taken off, should be ploughed in, to restore what the previous crops have taken out of the soil. It is quite possible, however, that the soil, in situations such as those advocated for the olive, may not be sufficiently good to make it worth while to attempt a green crop. In that case, rather than waste the space which is not wanted by the trees in their young state, pumpkins or sweet potatoes might advantageously be grown in holes specially manured, and fed to pigs. While, however, careful oultivation within certain limits between the trees may be permitted, not only must any crop be kept well away from the trees, but the soil about them must be periodically stirred as deeply as is compatible with safety to their roots.
Manures.—Manuring with suitable fertilizers, at intervals, forms an important element in the successful cultivation of the olive, especially in soils naturally poor. While the tree enjoys the mechanical looseness of sandy, gravelly, and stony soils, and freedom from stagnant moisture, it is not among the very small number of fruit-bearing trees which are most fruitful in sterile soil. Nutriment is necessary to its productiveness, and, if not already in the soil, must be introduced artificially. Stable-manure also acts mechanically in retaining moisture, thus helping the tree to withstand drought, and effecting a saving of labour in watering, which, if the manure has been well dug in, may be done less frequently. The stronger kinds of manures are recommended for the olive, such as pigeon- and sheep-dung ; but the best of all for sandy soils is night-soil. Raw, unripened, het manures of any kind are as bad for this tree as for most others. Nothing equals a good old compost heap ; and where the materials are procurable, it will well repay the labour and first cost to make one. This is best effected by excavating a hole of sufficient dimensions, into which should be thrown sheep- and fowl-dung, stable-manure, soot, ashes, refuse fat, scraps of leather, hoofs, urine, leaves, weeds, and other substances which will ferment and rot. The heap should be occasionally turned until thoroughly incorporated ; and when mature, which will probably not be for 12 months, may with great advantage be applied to the trees, being well turned in under the surface. In S. France, old rags of all kinds, including woollen, are largely used for manuring the olive. The tree likes limestone ridges, therefore an addition of lime to the compost heap, or its separate application, would soon make its effects visible in healthy appearance and more vigorous growth.