Page:The New International Encyclopædia 1st ed. v. 09.djvu/164

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.
*
140
*

GRAPE. 140 GRAPE CURE. distances for American vines. During the first year the land is given clean culture, with or without hoed crop; the second year the trellises or supports are partially constructed, and the new growlh tied up out oi' the way of cultivation. The third year the trellises are completed, some bearing wood left, and each vine may be allowed to bear a few clusters of fniit. After the first year no other crop should be allowed to incumber the vineyard. Clean culture should be given until midsummer, after which time means should be taksn to check growth and ripen the wood. Pruning the vine is based entirely upon the fact that the fruit is borne upon wood of the present season's growth, which arises from the buds of the last season's growth. All wood for fruiting purposes must, therefore, be one year old. All systems of pruning are either renewal or spur systems. Renewal systems seek to maintain the fruit production near the root or main trunk; spur systems renew on shoot spurs arising at intervals along a permanent arm. For descrip- tion of various systems, consult Bailey, Cyclope- dia of American Horticulture (New York, 1900). Besides the manufacture of wines, brandies, raisins, and the use of grapes for dessert pur- poses, unfermented grape-juice is becoming a valuable and popular product. This is made by expressing the juice, sweetening, heating to the boiling-point, and sealing while still hot in cans or strong bottles. See also Wine; Brandy; Rai- sins ; Currants : Vitace-e. OBAPE. Wild American, source of the Catawba, Isabella, etc. Grape Diseases. Few plants are subject to as many and as serious diseases as the grape, and few plant diseases have been more fully investigated. Diseases of the grape are caused by improper conditions of soil and moisture, but more frequently by fungi and bacteria, which are often carried from diseased to healthy plants by insects. A few of the more destructive and widely spread diseases may be briefly considered here. Doicny milrleif' {Flasmoparn riticola or Peronospora viticola) produces yellowish spots upon the upper surface of the leaves and a downy- frosty appearance beneath. Later these spots appear as light-brown discolorations. The same fungus occurs upon the fruit, when it is known as "brown rot' or 'gray rot,' according to the nature of the attack. The brown rot of the fruit is first manifested by purplish discolorations, scon after the appearance of which the pulp be- comes soft, and forms depressions, over which the skin is tightly drawn. The gray rot which at- tacks the young berries and their pedicels re- sembles the downy growth mentioned as occur- ring on the leaves. Downy mildew and black rot, ne.t to be discussed, are the two most serious general grape diseases. Black rot (Lw- stadia Bidtcellii) attacks the leaves at first as reddish-brown circular spots; later a number of spots may coalesce and form irregular blotches. Upon the fruit, the first sign of attack is the appearance of small brownish discolorations, which soon enlarge, the whole berry gradually becomes brown or black, withers, and finally dries up, usually remaining attached to the stem. An- thracnose (Splmci Ivma ampelimim) attacks leaves, stems, and berries. Upon the leaves it ap- pears as dark spots surrounded by well-marked darker bands of color. The centres later turn gray, and frequently the diseased areas fall out, giving the leaves a ragged appearance. Upon the shoots the disease manifests itself in much the same manner. On the fruit the disease is often termed 'bird's-e3"e rot,' from the peculiar appear- ance of the spots. The centres become gray, with an outer band quite dark and sometimes a zone of vermilion color between them. When the young fruits are attacked they turn brown, and pink pustules appear over the surface. The tissues of the berry with this rot become hard and leathery. Bitter rot (Glccosporiiim fructigenumj attacks, the stems and fruits, especially the latter, which become bitter, whence the name. In this disease the berries turn brown, become thickly dotted with purplish-black pimples, and ultimately fall at the least disturbance. The best preventive measures for these diseases is thorough spraying with Bordeau.x mixture. Poicdcry mildew {Vncinula spiralis) is trouble- some in gi-ape-houses and in the vineyards of France, but less in the vineyards of the United States. It covers the leaves, young shoots, and fruits with a powder.y, meal-like growth. Upon the leaves and fruits it forms patches of various size and shape on the upper surfaces. Soon the berries shrivel, the skin cracks, and other agents of decay complete the destruction. For the pre- vention of the disease, sulphur is perhaps the best remedy. It may be dusted over the vines in the open, or it may be evaporated without ignition in the grape-house. See Fungi, Economic : Dis- eases OF Plants; Fungicide. Consult: Tubeuf, Diseases of Plants Induced b;/ Cryptogamic Parasites, translated by W. G. Smith (New York, 1897) ; Pierce, "Grape Diseases on the Pacific Coast," in Fanners' Bulletin 30, United States Department of Agriculture (Washington, 1901) ; and the authorities referred to under Fungicide. GRAPE ANTHRACNOSE, Sphaeeloma am- peliuiim. A serious fungous disease of the grape most frequently seen upon the fruit as hard, scabby patches, but most destructive on the young growth and the fruit-stems as sunken, dis- colored pits. All prunings, leaves, and rubbish in the vineyard should be burned in early spring, and vines, posts, trellises, etc.. should be sprayed with strong solution of copper sulphate. See Fungicide. GRAPE CURE. A method of treatment of some diseases and conditions with a diet of which grapes form a very large part. This treatment is in vogue to some extent in France, but to .a much greater extent in Germany and in Hun- gary, in which countries, as well as in Austria and Switzerland, there are sanitariums at which the