Page:EB1911 - Volume 28.djvu/109

Rh historical or genealogical purposes than those which are the outcome of purely natural conditions.

The vine is hardy in Britain so far as regards its vegetation, but not hardy enough to bring its fruit to satisfactory maturity, so that for all practical purposes the vine must be regarded as a tender fruit. Planted against a wall or a building having a south aspect, or trained over a sunny roof, such sorts as the Black Cluster, Black Prince, Pitmaston White Cluster, Royal Muscadine, Sweetwater, &c., will ripen in the warmest English summers so as to be very pleasant eating; but in cold summers the fruit is not eatable in the raw state, and can only be converted into wine or vinegar. For outdoor culture the long-rod system is generally preferred.

When the plant is grown under glass, the vine border should occupy the interior of the house and also extend outwards in the front, but it is best made by instalments of 5 or 6 ft. as fast as the previous portions become well filled with roots, which may readily be done by packing up a turf wall at the extremity of the portion to be newly made; an exterior width of 15 ft. will be sufficient. If the soil beyond this is very unfavourable, the roots should be prevented from entering it by building a wall at the extreme edge of the border. Inside borders require frequent and thorough watering's. In well-drained localities the border may be partially below the ground level, but in damp situations it should be made on the surface; in either case the firm solid bottom should slope outwards towards an efficient drain. A good bottom may be formed by chalk rammed down close. On this should be laid at least a foot thick of coarse, hard, rubbly material, a layer of rough turf, grass side downwards, being spread over it to prevent the compost from working down. The soil itself, which should be 2 or 3 ft. deep, never less than 2 ft., should consist of live parts rich turfy loam, one part old lime rubbish or broken bricks, including a little wood ashes or burnt earth (ballast), one part broken charcoal, and about one part of half-inch bones, the whole being thoroughly mixed, and kept dryish till used. It is well after the borders are completed to remove the top soil, in which no roots are to be found, every two or three years, and to replace it with a mixture of good loam, rotten manure, lime rubbish and bone meal, to the depth of 6 or 7 in. A mulch of half-decayed stable litter is useful to prevent loss of moisture in summer.

Young vines raised from eyes, i.e. buds having about in. wood above and 1 in. below, are generally preferred for planting. The eyes being selected from well-ripened shoots of the previous year are planted about the end of January, singly, in small pots of light loamy compost, and after standing in a warm place for a few days should be plunged in a propagating bed, having a bottom heat of 75°, which should be increased to 85° when they nave produced several leaves, the atmosphere being kept at about the same temperature or higher by sun heat during the day, and at about 75° at night. As soon as roots are freely formed the plants must be shifted into 6-inch pots, and later on into 12-inch ones. The shoots are trained up near the glass, and, with plenty of heat (top and bottom) and of water, with air and light, and manure water occasionally, will form firm, strong, well-ripened canes in the course of the season. To prepare the vine for planting, it should be cut back to within 2 ft. of the pot early in the season, and only three or four of the eyes at the base should be allowed to grow on. The best time for planting is in spring, when the young shoots have just started. The vines should be planted inside the house, from 1 to 2 ft. from the front wall, and from 6 ft. to 8 ft. apart, the roots being placed an inch deeper in the soil than before, carefully disentangled and spread outwards from the stem, and covered carefully and firmly with friable loam, without manure. When the shoots are fairly developed, the two strongest are to be selected and trained in. When forcing is commenced, the vinery is shut up for two or three weeks without fire heat, the mean temperature ranging about 50°. Fire heat must be at first applied very gently, and may range about 55° at night, and from 65° to 70° by day, but a few degrees more may be given them as the buds break and the new shoots appear. When they are in flower, and onwards during the swelling of the berries, 85° may be taken as a maximum, running up to 90° with sun heat and the temperature may be lowered somewhat when the fruit is ripe. The temperature must, however, be regulated according to the variety. Muscats requiring a higher temperature from the time their bunches show than Hamburghs. As much ventilation as the state of the weather will permit should be given. A moist growing atmosphere is necessary both for the swelling fruit and for maintaining the health of the foliage. A due amount of moisture may be kept up by the use of evaporating troughs and by syringing the walls and pathways two or three times a day, but the leaves should not be syringed. When the vines are in flower, and when the fruit is colouring, the evaporating troughs should be kept dry, but the aridity must not be excessive, lest the red spider and other pests should attack the leaves. In the course of the season the borders (inside) will require several thorough soakings of warm water—the first when the house is shut up, this being repeated when the vines have made young shoots a few inches long, again when the vines are in flower, and still again when the berries are taking the second swelling after stoning. Outside borders require watering in very dry summer weather only.

2.

1. Vine leaf attacked by mildew, Uncinula necator (Erysiphe Tuckeri), which forms white patches on the upper face, reduced.

2. Grapes similarly attacked.

3. Portion of the mycelium of the fungus bearing spores (conidia). s, on erect branches.

4. Perithecium or "fruit" of the fungus with its curled appendages.

5. Ascus from perithecium containing six spores. There are three principal systems of pruning vines, termed the long-rod, the short-rod and the spur systems, and good crops have been obtained by each of them. It is admitted that larger bunches are generally obtained by the long-rod than by the spur system. The principle of this mode of pruning is to train in at considerable length, according to their strength, shoots of the last year's growth for producing shoots to bear fruit in the present, these rods are afterwards cut away and replaced by young shoots trained up during the preceding summer; and these are in their turn cut out in the following autumn after bearing, and replaced by shoots of that summer's growth. By the short-rod system, short instead of long rods are retained, they are dealt with in a similar manner. The spur system has, however, become the most general. In this case the vines are usually planted so that one can be trained up under each rafter, or up the middle of the sash, the latter method being preferable. The shoots are cut back to buds close to the stem, which should be encouraged to form alternately at equal distances right and left, by removing those buds from the original shoot which are not conveniently placed. The young shoots from these buds are to be gently brought to a horizontal position, by bending them a little at a time, and tied in, and usually opposite about the fourth leaf the rudiments of a bunch will be developed. The leaf directly opposite the bunch must in all cases be preserved, and the young shoot is to be topped at one or two joints beyond the incipient fruit, the latter distance being preferable if there is plenty of room for the foliage to expand; the lateral shoots, which will push out after the topping, must be again topped above their first or second joints. If the bunches are too numerous they must be thinned before the flowers expand, and the berries also must be properly thinned out and regulated as soon as they are well set, care being taken, in avoiding overcrowding, that the bunches be not made too thin and loose.

The cultivation of vines in pots is very commonly practised with good results, and pot-vines are very useful to force for the earliest crop. The plants should be raised from eyes, and grown as strong as possible in the way already noted, in rich turfy loam mixed with about one-third of horse dung and a little bone dust. The temperature should be gradually increased from 60° to 80°, or 90° by sun heat, and a bottom heat a few degrees higher must be maintained during their growth. As the roots require more room, the plants should be shifted from 3-inch pots into those of 6, 12 or 15 in. in diameter, in any of which larger sizes they may be fruited in the following season, but, to be successful in this, the young rod produced must be thoroughly matured after it has reached, its limit of growth. The periodical thorough cleansing of the vine stems and every part of the houses is of the utmost importance. The number of varieties of grapes possessing some merit is considerable, but a very few of them will be found sufficient to supply all the wants of the cultivator. For general purposes nothing approaches the Black Hamburgh (including Frankonthal) in merit.

Fungoid Diseases.—The most destructive form of fungoid disease which attacks the vine is caused by a mildew, Uncinula necator (Erysiphe Tuckeri) (fig. 2). The disease was first noticed in England in