GRAPE VINE 



397 



GRAPE VINE 



draining and the incorporation of calcareous rubbish, 

 and in the second case, protection to the border and stem, 

 will remove the evil. If the sap be not duly elaborated, 

 it must arise, either separately or conjointly, from the 

 leaves vegetating in an ungenial atmosphere, or from 

 their being too reduced in number. 



If the roots of the vines are found to have penetrated 

 the soil deeply, they should be lifted very carefully, 

 brickbats placed beneath the roots, and these trained 

 about nine inches beneath the surface. If drainage of 

 the border has been neglected, let it be put right at the 

 same time. If the loss of the crop which would be 

 occasioned by the lifting of the whole of the vines would 

 be inconvenient, only one or two can be so treated in 

 successive autumns. The most injurious time for an un- 

 natural disparity of temperature in the air and soil to 

 occur is at night ; for, as was justly observed by the late 

 Mr. Knight, an ill effect of high temperature during the 

 night is, that it exhausts the excitability of the tree much 

 more rapidly than it promotes the growth or accelerates 

 the maturity of the fruit, which is, in consequence, ill 

 supplied with nutriment at the period of its ripening, 

 when most nutriment is probably wanted. The Muscat 

 of Alexandria, and other late grapes, are, owing to this 

 cause, often seen to wither upon the bunch hi a very 

 imperfect state of maturity ; and the want of richness 

 and flavour in other forced fruit is often attributable 

 to the same cause. The Frontignans are among the 

 varieties apt to shrivel under great disparity of tempera- 

 ture between the roots and branches. 



Somewhat allied in its causes to shrivelling is that 

 unsightly imperfection where the berries do not come to 

 maturity at the point of the bunches, leaving from five 

 to ten quite colourless and sour, though others on the 

 same bunch are fine and large. In such case the 

 remedies are to give more heat and air, keeping the 

 border warmer than before, and to avoid cold damps in 

 the house : leave as much foliage as can be exposed fully 

 to light. The leaves removed must be by little at a 

 time. In thinning, clip off a few berries at the lower 

 extremity of the bunch ; the rest will swell better. 



Shanking is an ulceration, or gangrene, attacking the 

 footstalks of the bunches, and appears to be occasioned, 

 like shrivelling, by the temperature of the soil being 

 too much below that hi which the branches are vege- 

 tating ; and, consequently, the supply of sap to the 

 grapes is much diminished, and the parts which thus fail 

 of support immediately begin to decay. This is an effect 

 always the consequence of a diminished supply of sap, 

 apparent either in the leaves, flower, or fruit. The 

 disease, like every other putrefaction, does not ad- 

 vance rapidly unless there be much moisture in the atmo- 

 sphere. 



The coldness of the soil causes this torpidity in the 

 action of the root ; and this, perhaps, at the very period 

 when the greatest demand is made upon it to sustain 

 the excessive transpiration which is going on hi the leaf, 

 and to furnish fresh matter for elaboration, to both 

 which ends it is frequently quite inadequate, owing to 

 drenching rains. If the young fibre be examined at such 

 inclement periods, it will be found somewhat discoloured, 

 and, in some cases, quite rotten. Shanking, we conceive, 

 is generally caused by the unnatural disagreement of 

 temperature between the root and top, independent, in 

 the main, of the question of moisture. It generally 

 occurs with vines which have been somewhat forced ; 

 seldom on open walls seldom with vines forced in pots 

 or tubs. The obvious prevention of shanking is securing 

 a congenial relative temperature to the roots and foliage. 



Rust comes upon the berries hi the form of a rough, 

 rusty appearance of their skins, which have, in fact, 

 become thick and indurated. Some think it arises from 

 their being handled, or the hair of the head touching 

 them ; but the disease is often too general to admit of 

 this topical explanation. We believe it to arise from an 

 overheating of the vinery, however unintentional, whilst 

 the grapes were young, and thus tending to force them 

 to a premature rapidity of growth. Any excessive 

 pressure upon the cuticle, whether from within or from 

 without, causes its thickening. This considerable eleva- 

 tion being succeeded by a sudden reduction of tempera- 

 ture, will almost certainly induce the disease. 



The Spot affecting the berries seems to be the same 

 disease as shanking, only affecting a different part. Like 

 this disease, it is a gangrene, and is probably occasioned 



by an irregularity in the supply of moisture and vicissi- 

 tudes of temperature, but especially if one of the ex- 

 tremes is much below the degree of heat most favourable 

 to the healthy growth of that plant. Muscats are par- 

 ticularly liable to the spot. Our opinion that sudden 

 vicissitudes of temperature are the causes of this disease, 

 seems to be well sustained by the fact, that the parts 

 nearest the glass, that is, the upper portions of the 

 bunches, and those parts most exposed to the sun's 

 influence, are the first to suffer ; and this, also, goes far 

 towards substantiating the assertion, that the shade 

 of the foliage is necessary to the well-doing of grapes. 



Want of Colour is often a defect of the Black Grape, 

 but not at all necessarily arising from deficient light. 

 The green colour of leaves depends entirely upon the 

 presence either of light or of uncombined hydrogen gas ; 

 but vegetable reds, purples, and other colouring matters 

 of fruits are formed, though less intense, even in a total 

 absence from light. So far from full exposure to light 

 being requisite for the full colouring and ripening of 

 grapes, they never attain these desired qualities so well 

 as when shaded by one thickness of leaf. The colouring 

 matter of all fruit is dependent partly upon the leaves 

 immediately above it, and partly upon the fruit itself, 

 the necessary digestion of the sap being commenced in 

 the one and perfected in the other. If this digestion or 

 elaboration of the sap is checked by ungenial tempera- 

 ture, but more particularly if the crop is too heavy for 

 the vine, or if the leaves, especially above the bunches, 

 are too much thinned, defect of colour will be the very 

 usual consequence to the berries. We have seen the 

 blackest of berries in situations where the sun had never 

 shone on them since they blossomed ; indeed, it only 

 requires a little close observation for one season to dispel 

 such a fallacy. It sometimes, however, happens that 

 the principal leaves on the same shoot with the bunch are 

 shaded by other main leaves, or by laterals. Such 

 shading is sure to be prejudicial to the colouring of the 

 berry, as well as to the maturation of the buds connected 

 with the shaded leaves. And here we have one of the 

 reasons for such close stopping as the vine is subjected 

 to. Over-cropping alone will lead to bad colouring ; 

 indeed, is one of the most fruitful sources of it. It 

 exhausts the tree of every particle of prepared sap, and 

 produces debility hi the root, which renders it readily 

 susceptible to the stagnating rains of an unpropitious 

 season. 



In order to promote good colouring, the ripening 

 process should not be hurried. It is evident that very 

 high temperatures are not required for this purpose, for 

 the Black Hamburgh, on common walls, is not deficient 

 in colour, hi a good season. Now, the colouring process, 

 in the latter case, occurs in the end of September, when 

 the temperature at night must sometimes be near the 

 freezing-point. It is a common observation of practical 

 men, that the cold nights of autumn hasten maturity in 

 many crops ; and this is undoubtedly a fact, and trace- 

 able, we presume, to a cessation of the growing principle, 

 causing thereby a concentration of the energies of the 

 plant. We would say, therefore, beware of too high a 

 temperature during the colouring process, unless accom- 

 panied with much solar light, and even then avoid 

 extremes. We would more especially avoid night heat 

 at this period, and would promote a circulation of air 

 night and day. 



Bleeding. This only occurs to the vine from the un- 

 healed surfaces of cuts made after the sap has commenced 

 its motion, and before the leaves are well expanded. A 

 red-hot iron, applied to the bleeding surface until it be 

 charred, will stop the effusion of sap for a tune, if not 

 permanently ; and to effect a complete stoppage at 

 once, coat the charred surface, and rub well into it a 

 paste made of lime newly burnt and grease. This 

 hardens and forms an effectual plaister. 



Mr. Knight's plaister we know to be effectual, and is 

 thus composed : 



One-fourth of calcined oyster-shells, beaten to fine 

 powder in a mortar, and three-fourths of cheese, worked 

 together until they form a sort of paste. This mixture, 

 pressed into the pores of the wood, either with the thumb 

 or any other means, will effectually stop the flow of the 

 sap : sometimes a repetition may be necessary, if it is 

 not well forced into the pores. See MILDEW. 



Insects. See ACARUS, APHIS, Coccus, CURCULIO, and 

 THRIPS. 



