The Raisin Industry / A practical treatise on the raisin grapes, their history, culture and curing

Drainage.

—Drainage is necessary in all vineyards where large quantities of water are used for irrigation, and principally at the very time that subirrigation begins. Thus in Fresno county the best raisin vineyards are those in which the land is both subirrigated and drained. When irrigation commences in any certain district, no one thinks of drainage as a possibility, and great carelessness is shown in locating ditches and other irrigation works. But in a few years, when the soil is full of water which finds no outlet, drainage becomes both necessary and desirable. A very successful and highly necessary drain has been constructed through a part of the Fresno district, which so filled up with water during the rainy winter of 1883-84 that much of the ground could not be plowed until late in the spring. The drain remedied the evil and drained the soil, and the vineyards grown there are now counted among the best and most profitable. The water thus drained off lowered the water level from six to seven feet. In very dry seasons this ditch is filled with water, and serves then to keep the soil moist through seepage or subirrigation.

The Influence of Irrigation on the Soil.

—It is by many considered that irrigation helps to fertilize the soil. The spring and flood water contain great quantities of mud and humus, which when spread over the land will greatly increase its fertility. Even ordinary river water contains salts and other ingredients, which will fertilize the soil to no small degree. Another cause of the increased fertility of subirrigated soils is that the water which constantly evaporates carries with it salts, etc., from the lower strata up towards the surface, and makes them accessible to the roots of the vines. But, on the other hand, if the water or the soils contain alkalies or other destructive substances, these also are deposited on the surface to the great detriment of the vines, and often to such an extent that the vines will die or become sickly. Too abundant flooding may also leach out of the soil its soluble salts, and carry them deeper down in the ground. But if this soil after a while fills up with water and becomes subirrigated, the evaporation of water from the surface will gradually carry these salts back to the surface, when they will increase the fertility of the soil. Where drainage is very perfect, constant irrigation will gradually rob the soil of many of its soluble salts, and carry them to places where they will forever be out of the reach of the vines. To ascertain these facts and conditions, every vineyardist should have the soil analyzed about every five years, and too great care cannot be taken to keep the soil of proper strength.

Another influence of irrigation on the soil may also be mentioned here. Some of the soils in the irrigated districts which were formerly very hard and difficult to work have in course of time changed and become mellow. The water has undoubtedly caused a chemical and mechanical decomposition of the components of the soil, which has caused it to continually improve. Even certain kinds of hardpan have been known to dissolve when irrigated, and to change into useful and mellow soil, in which the vines can find nutriment. Such hardpans are those which are generally found in very dark red soils; those in lighter soils are not so readily dissolved.

THE RAISIN GRAPES.

Introductory Notes.

—The raisin grapes might be divided into two classes,—proper and genuine, such as Muscats, Sultanas and Currants, and irregular or inferior raisin grapes, such as Malagas and Feher Szagos. Now-a-days almost any kind of grapes are dried and sometimes called raisins, but the proper name for them should be dried grapes. With these we need not here busy ourselves, as with a few exceptions they are of little value, and cannot be compared with the regular raisin grapes, either as regards quality, demand or price.

Muscatel or Gordo Blanco.

—This variety is the best type of the raisin grape of Malaga. Its growth is low and spreading, with no upright branches in the center. Its bunches are heavy, and, when perfect, close and shouldered. Its berries are round and large, the greatest circumference being at the center. A crease is often found at the apex of the berry. The color is green, or, when fully ripe, amber green or yellow. As compared with the Muscat of Alexandria, this variety is distinguished, when perfect, by its low, depressed growth, without any upright branches in the center of the vine; by a closer bunch; by rounder berries, and by a thicker and firmer bloom. The berries set better than those of the Muscat of Alexandria, although both varieties suffer from the early stages of oidium or colure. The Gordo Blanco is the choice raisin grape for the San Joaquin valley, and for the interior generally. It is the raisin grape of Malaga in Spain, where it is probable the variety originated. Importations of this variety have been made to California at various times by A. Haraszthy in 1861, and by W. S. Chapman in 1876.

Muscat of Alexandria.

—The growth of this variety is upright in the center. Its clusters, even when perfect, are never close. Its berries are oblong and tapering, the largest circumference being near the apex. The color when fully ripe is amber green or yellowish green. The leaves of both varieties of Muscats are five-pointed, light green, lighter below, and do not differ materially from each other. Both Muscats are remarkable for their second and third growths, and for the large second crop on the laterals.

The Muscat of Alexandria, as compared with the Gordo Blanco, is characterized by its oblong berries, and by its more upright branches in the center of the vine. Its growth is more straggling than that of the Gordo Blanco, and, planted side by side, the two varieties are distinctly characteristic. The Muscat of Alexandria is the favorite raisin grape in Southern California, where it seems eminently adapted. I found no other Muscat in San Bernardino and San Diego counties. The most magnificent bunches of this variety which I have ever seen were grown there only a few miles from the ocean,—bunches that could not be surpassed, and which certainly were equal in weight to any Gordo Blanco that have ever come under my notice. A. B. Butler considers that the Muscat of Alexandria does equally as well as the Gordo Blanco in Fresno, but most growers are not ready to agree with him.

The raisin made from the Muscat of Alexandria looks smaller on account of its oblong form, and is less suited for facing the boxes, but as to other qualities, such as taste, sweetness and color, there is no marked difference between these two varieties of Muscats. All varieties of Muscats set better in moist air than where the air is very dry, and the moister air tends to better develop the bunches. This explains why, in isolated vineyards in the interior, the bunches are never so large as where a large number of acres of vines have modified the often excessive dryness of the atmosphere. As to the relative distribution of these two varieties of Muscats in our State, it may be stated that the former is not based upon any particular adaptability of the respective varieties to the localities where they are grown. The Muscat of Alexandria is the older variety of the two, probably both in Spain as well as in California. To Valencia in Spain it was brought by the Moors from Africa, or possibly from Alexandria in Egypt. The Gordo Blanco again appears to be a native Spanish variety, especially adapted to the warmer region of Malaga or Southern Spain. The Gordo Blanco is the principal grape of Malaga; the Muscat of Alexandria is the one grown in Valencia and Denia and also in Smyrna in Asia Minor.

In California the Gordo Blanco is found around Woodland in Yolo county, throughout the San Joaquin valley, and in Fresno it is the favorite and almost exclusive Muscat grape. The Muscat of Alexandria is grown in Solano county and elsewhere in Northern California, while it is the exclusive grape in Riverside, Redlands, Orange county and El Cajon, and probably elsewhere in San Diego county or Southern California generally. The Muscat of Alexandria was imported by Colonel Agoston Haraszthy in 1852 from Malaga, and by D. M. Delmas some thirty-eight years ago from France.

Huasco Muscat.

—This variety (pronounced Uasco) resembles very much the Muscat of Alexandria, of which it is probably a seedling, and was introduced into Chile by the Spaniards soon after the conquest. According to Professor E. W. Hilgard, this variety sets better than the Alexandria, and on that account deserves to be cultivated. It is strange that no attempts have been made in this country to grow it on a larger scale. The Huasco is undoubtedly one of the most interesting grapes, and the fact that it produces the most expensive raisins in the world should be a sufficient inducement to our California growers to at least study the variety closely. I should think that El Cajon valley would be the proper locality for it in this State.

Other Varieties of Muscats.

—A variety of Muscatel resembling the Gordo Blanco, but with more erect growth, is said to have been imported by G. G. Briggs of Davisville, Solano county. I have seen it growing in the vineyard of George A. Freeman of Fresno, but cannot distinguish its berries from those of the Gordo Blanco. The growth of the vine is more erect, and leaves the center of the vine rather uncovered and exposed. I would decidedly prefer the Gordo Blanco. A seedling of the Gordo Blanco originated by the author is now growing on the Floreal vineyard, owned by J. T. Goodman, near Fresno. This variety promised a great deal the first season. I have no doubt that, with some selection of berries and bunches, many new and valuable raisin grapes could be originated in this State, varieties which would be especially adapted to our soil and climate. While our fruit-growers have produced a number of new fruits of various kinds, we have yet to hear of the first superior grape seedlings. According to the Rural Press of May 5, 1877, C. T. Ward of Haywards, Alameda county, raised some seedlings from Huasco seed, but what has become of them I do not know. Haywards would not be likely to be a proper place for raisin grapes, and even the best variety could not possibly be a success there.

J. T. Goodman of Fresno has a Muscatel vine in his vineyard which ripens ten days earlier than the Gordo Blanco, but whether it is a seedling is not known. It may prove a most valuable variety if extensively grown. B. G. Stabler of Yuba City tells me that Ch. E. Swezy, near Marysville, has raised a seedling from an imported Dehesa raisin, which in size, flavor and all other qualities excels any other table grape known, but the flavor of the grape does not resemble that of the Muscatel. I have seen raisins made from this grape, but they were not desirable; but as a table grape this variety is said to be superior. If so, this grape should be tried in different localities, and may prove a real acquisition. There is no doubt that other seedling raisin grapes have been raised in this State, and we hope in course of time to know all about them.

Seedless Sultana.

—This grape is decidedly one of the most important raisin grapes known. Its bunches are very large, sometimes weighing five pounds each. The berries are round and seedless, the size of large peas, of a green color, which, when the grape ripens, turns bright amber yellow, with small brown spots. The leaves are large and very entire, and more yellowish than those of the Muscat. The growth of the vine is upright, with erect or climbing branches. This grapevine in order to bear must be pruned long, and should properly be staked from four to five feet high. The yield of the Sultana is very heavy, and as much as sixteen tons of fresh grapes are frequently harvested from an acre, provided the soil is the very best possible. The grapes begin to color and sweeten several weeks before the Muscat, but they become fully ripe later than this variety, and are on that account not as extensively grown as they certainly deserve to be. For districts with long summers and autumns the Sultana will prove a very profitable and desirable grape. The native home of the Sultana is Asia Minor. There it is grown principally around Smyrna and in several of the islands in the Archipelago. In California only few Sultana vineyards are planted; still there is undoubtedly a great field for this grape where the seasons are long enough to allow of its perfect ripening. The raisins are light in color and somewhat acid, but with no particular flavor, and in this respect are inferior to the Muscats and the Currants. They are produced either by dipping, as is done in Smyrna, or by sun-drying, as we do in this State. If the dipping process is used, the grapes must be very ripe, else they will turn reddish and dark and lose quality. In California the Sultana grape does well, and only seldom produces seeds. In Eastern Mediterranean countries, except in the few favored spots of Smyrna, or in some of the Islands, this variety rapidly deteriorates and becomes seed-bearing, which of course entirely ruins its usefulness. The Seedless Sultana was first brought to California by Colonel Agoston Haraszthy in 1861.

Black Currant.

—This variety is but little known in this State. The growth is erect and climbing. The bunches are long, narrow and cylindrical, with heavy shoulders. The berries are small, of the size of peas, seedless and black, very sweet and with a peculiar aroma not found in any other variety. The Black Currant should be pruned short, and the young branches require staking in order to bear well. The home of the Black Currant is the Grecian Islands as well as Morea, especially around Patras. Zante, Cephalonia and Ithaca all produce Currants of the highest quality.

Other Varieties of Currants.

—The White Currant grown in California is not the true raisin grape which produces the Currant of commerce. The bunch and berry resemble the Black Currant, but differ in not being black, and in lacking the peculiar aroma and flavor alone possessed by the Black and true Currant. There are in Greece several other varieties of Currants, such as red and gray, but these are used for wine and not for raisins. The White and Red Currants were introduced from Crimea in 1861 by Colonel Agoston Haraszthy.

Thompson Seedless.

—This variety has been growing in California for many years, but has only lately come into notice. It was imported from Rochester, New York, from the establishment of Elwanger & Barry, about 1872, and was by them described as a grape from Constantinople under the name of Lady Decoverly. Thompson Seedless is the name given this grape by the local growers around Yuba City, and not the original name. I am inclined to believe that this grape is related to, but not identical with, the oblong, seedless grape which is grown around Damascus in Asia Minor, and there dried into a raisin of very good quality. This Damascus grape is brownish when ripe. Thompson Seedless is an oval grape, greenish yellow, as large as a Sultana, seedless, with thin skin, good but not strong flavor, and without that acid which characterizes the Sultana grape and raisin. The bunches are large, or very large, and the vine is an enormous bearer. As yet it is principally grown around Yuba City and Marysville in limited quantities, but the raisins are in good demand. When sun-dried and cured, these raisins are bluish and dark like Muscats, but narrower and more tapering, and only a quarter the size. Their sweetness and taste commend them for cooking purposes, and the bearing quality of the vine will no doubt make their growing profitable in all places where the seasons are too short to thoroughly ripen the Sultana. In Yuba this grape ripens early in August.

Other Seedless Grapes.

—In the Islands of Lipari and Pantelleria a coarse but seedless grape is grown, out of which a variety of Sultana raisin is made. We have no further notices and description of this variety.

Malaga.

—This is not a real raisin grape, but of late years raisins have been made from it and found both fair in quality and profitable to the grower. The Malaga is a heavy bearer of one crop of very large but loose bunches. There is no second crop. The berries are large, oval, not tapering, the flesh is meaty and solid, very sweet, but with no decided flavor. The skin is thick and green, when ripe amber yellow, with thick bloom. Raisins made of this grape are very large, and the bunches are also large and solid, and the berries are not easily torn off. When sweated, the skin becomes thinner, and the quality improves generally. The Malaga is a very hardy vine, not particular about soil, a strong grower, bears well, and its grapes ripen at the time of the Muscats. But, as there is no second crop, the vintage of the Malaga will be over long before that of the Muscats, and out of the way of rain or fog. This is what makes this grape so valuable. Four cents per pound has been paid for these raisins in sweatboxes for the past two years, and at that price this grape pays better than the Muscats. The Malaga raisins are also very heavy and solid. I am satisfied that there will be a good demand for this raisin, especially among consumers, who prefer a bunch raisin, but who do not care to pay for the expensive packing which is necessary to preserve the Muscat bunches. The Malaga raisin could be sold in bulk, and still would not break up. The Malaga grape is grown in many places in California, and is used principally as a table grape; it has only been cured and dried into raisins in Fresno. According to A. B. Butler, this grape is grown in Malaga for table purposes.

Feher Szagos.

—Feher Szagos raisins have been in the market for several years, and have brought in sweatboxes from three to three and a half cents per pound. This grape is a heavy bearer and grower, branches erect but slender, leaves glossy, entire, bunches medium to small, pointed and solid. The berries are greenish amber, medium, oval, pointed, with thin skin, and few and small seeds. The flesh is not firm, but dries well, and when dried the raisin is very good, with a peculiar flavor of its own. They are only used for cooking, but are nevertheless rather good raisins to eat, and their seeds are so soft that they are not objectionable. The bearing quality of the Feher Szagos is very heavy, as much as sixteen tons of green grapes having been raised to the acre, and from ten to twelve tons is a common yield. It ripens with the Muscat, and the vine bears only one crop. At three cents per pound, the Feher Szagos is a profitable grape. The native home of this variety is Hungary or Southern Austria, the name meaning, in Hungarian, White Jack. In Fresno it is grown quite extensively, having originally been planted as a wine grape. As such it is highly valued, producing an abundance of highly flavored sherry.

Other Raisin Grapes.

—In Asia Minor, the Grecian Islands, Morea, Italy, Spain and Morocco, there are grown a number of varieties of grapes which are cured into raisins and sold as such. Many of these are little, if any, better than our dried grapes, while others again are superior, more resembling the regular raisins. Among the latter we have the Spanish Black and Red, and the Smyrna and Turkish Black and Red. Some of them belong to the Muscat family, probably resembling Black and Red Muscats, but of these varieties we have no particular information, and our growers will probably not lose much by avoiding a more intimate acquaintance with them.

DISEASES AND INSECT PESTS.

POWDERY MILDEW OR UNCINULA.

General Notes.

—This disease of the grapevine is caused by the growth of parasitic fungus known in Europe as Oidium Tuckeri, and in this country as Uncinula spiralis or powdery mildew. I am satisfied the two names signify the same fungus, only the European form has never been found as highly developed as the American one, which has on that account received a name of its own. If the two are identical, then the European Oidium, which for many years caused the destruction of the transatlantic vineyards, was imported to that country from this. The Uncinula spiralis is undoubtedly native on our indigenous vines.

Characteristics.

—The mildew appears in two different stages, one in the spring when the vines are in blossom, the other again later in the summer when the fruit is more advanced. The first stage of the mildew resembles a fine cobweb spun between the flowers of the bunch. If allowed unrestricted sway, the flowers will drop off, the fruit will never set, or set only imperfectly, and the crop will be a great loss or even a total failure. Generally the inexperienced vineyardist does not perceive the mildew until too late. A slight touch to the vine will then bring down all the young fruit or blossoms like a shower, and the stem of the bunch will be seen to be entirely bare, or with only a few scattered berries. This form of the Uncinula mildew has not been as scientifically investigated as would be desirable, and nothing is known as regards its development. It is possibly a primary generation and early stage of the later Uncinula. I believe this form of the mildew is identical with the disease which is called Colure by the French, and which is characterized by the dropping of the young, undeveloped grapes. The first appearance of this mildew is always accompanied by white, salty excrescences on the edges of the grape leaves. Whether they are directly or indirectly connected with the fungus is not known.

The later form, the powdery mildew, and the form which has given this mildew its name, appears later in the season, when the grapes are half grown or more. It then takes the shape of fine powder-like patches or blotches on the upper side of the leaves, stems or berries. These spots are of a dull gray or whitish gray color, and smell strongly of mold or mushrooms. If these mildew spots when young are rubbed smooth, especially on the green stems or berries, we see below them, in the epidermis of the vine, the mycelium or stem of the fungus spreading in all directions from a central point, like the roots of a tree or plant. This part of the mildew corresponds with the stem and root of a plant, while the upper, powdery part is the one which produces the spores or the seed, conidia and peritheca, all of which are reproductive organs. The grapes thus attacked gradually dry up or crack open. The leaves are eaten through and dry up, and the whole plant becomes badly diseased, and may even die.

History and Distribution.

—The powdery mildew or Oidium was observed for the first time in the year 1845 in hothouses in England. It immediately began to spread, and in a few years infested all the vine districts of the Old World. Before any remedy had been discovered, many vine districts were so injured that they have not since been able to recover. Thus in 1850 and 1851 France suffered greatly from this mildew, and the Island of Madeira, which for three hundred years had produced the finest wines, had its grapevines so injured that they up to this time have not again produced as good a quality of grapes as before the advent of the disease. The Grecian Islands as well as Morea were also visited by the powdery mildew, and though the latter is now kept in control, the general opinion is that the quality of the currants is not as high as it was before the mildew appeared. Now there is probably no place in the Old World where grapes are not attacked by this mildew, although some places are injured much more than others. Adjoining vineyards are often differently attacked, some being even entirely free, while others are visited yearly. Young vines are less attacked than old ones, and in favorable places the mildew seldom infests vines before they are two or three years old. Elevated places and localities exposed to winds and cold are generally attacked by the first stages of this oidium, while its second or last stage prefers low, damp places exposed to dew or fog.

The American form of the powdery mildew or Uncinula spiralis differs in some respects from the European Oidium, not as to its effects, but as to its microscopical characteristics. The Oidium occurs in Europe only with certain generative organs called gonidia, while the American Uncinula also develops so-called peritheca. It is more than probable that both fungi belong to the same species, but until these perithecal organs have been found on the European Oidium, the proper name for our mildew must be Uncinula, and not Oidium. It is also probable that the Uncinula fungus is a native of this continent, and that it from here has spread to Europe, where the natural conditions are such that only the gonidial form of the fungus has been able to develop. In general appearance and in their effects the Uncinula and Oidium are identical.

The Oidium appears sooner on poor soil and on exhausted vines, and vines in which the flow of the sap for some reason or other has been checked are more subject to the mildew than those which are yet in full growing vigor. Elevated vines on trellises which are much exposed, and vines which are so covered up that the air has little access, are the first ones to be attacked, and those which will suffer the most. The powdery mildew affects all varieties of grapes, but some kinds more than others. The Muscats are among those which suffer considerably, and if not sulphured would in severe cases neither set nor bear suitable grapes. The Malaga is less affected, and so is the Sultana. In new districts the Uncinula does not appear until the vines are older. Thus in the Fresno district the earliest vines did not suffer from mildew until they became five years old, but now the mildew would destroy the grapes every year, in case they were not treated with sulphur.

Remedies.

—The most common and perhaps the best remedy is powdered sulphur. The latter is applied either with the dust can or “dredger,” or with bellows. The dust can is used when the vines or vine shoots are yet small, and the bellows when the vines are larger. The first sulphuring should be done when the young shoots are six inches long, immediately before the bloom, and the second time when the berries are well set. Sulphuring as a regular vineyard operation will be more fully discussed further on.

DOWNY MILDEW OR PERONOSPORA.

General Notes.

—The downy mildew is a fungus known botanically as Peronospora viticola. Its native country is the United States, but its greatest damage is done in Europe. It appears as white, downy spots on the underside of the grape leaves, which are gradually destroyed, and later on attacks the berries, which shrivel and spoil. In California the downy mildew occurs frequently on wild native grapevines, but only very rarely on the cultivated Asiatic vines. Dr. H. W. Harkness, the eminent mycologist, found it only once on cultivated vines in the Sacramento river bottom. These vines were growing close to native vines, from which the fungus had spread. There is no fear that this fungus will ever spread and cause damage in our State as long as the vineyards are given plenty of air. In France the Peronospora has caused much damage, but is now being combated with bluestone and lime solutions, according to the following formula: Slake thirty pounds of lime in seven and a half gallons of water, also mix sixteen pounds of bluestone (copper sulphate) in twenty-five gallons of water. Mix the two together, and either sprinkle the foliage with it, or dilute it further with say five hundred gallons of water and spray the vine leaves on both the upper and lower sides. According to Dr. Harkness the efficiency of this spray cannot always be relied on. So far no other fungi have appeared in the raisin districts of this State, nor have we reason to fear that any will attack the vines.

THE VINE PLAGUE.

Characteristics.

—The first, or at least the most characteristic signs of this disease appear especially after a summer rain, or after the first fall rain. The leaves then become spotted with yellow. The following season these yellow spots appear as if fused together, and many leaves become entirely yellow, except the veins, which stand out bright green. Some leaves are invaded by the yellow from the edges, while the veins as before remain green. These yellow spots soon turn brown, the leaves dry up and curl slightly backwards and finally fall off, leaving the canes bare. During the very first appearance of the vine plague, many leaves turn brown and dry up in certain spots in the vineyard without the previous appearance of any yellow spots. The drying of the leaves proceeds either from the center of the spots, or from the margin of the leaves, destroying both the leaves and their veins. Later on in the fall a new crop of leaves appear, but these leaves are small or very small, bright green and sickly, and do not continue to develop after they have reached a certain size, different in different vines. In red varieties of grapes, the yellow spots in the leaves gradually turn red or claret colored, often resembling the most beautiful autumn leaves. In districts where the disease is common, these leaves are generally known as calico leaves on account of their peculiar markings.

The canes do not attain their regular growth, and fail to mature in the fall, or mature only in spots, the balance of the wood remaining dull green. The inner parts of the canes are, as a rule, more mature than the tips. Very often only one or two joints nearest the stem mature, and in bad cases no part of the canes mature, but at the advent of the rain turn black and die. Late in the fall the tips of the green canes turn black, dry up and snap off like glass when touched. The pith turns in the older canes dark brown, dries up prematurely and dies, while in very young canes the pith remains watery like a semi-transparent jelly.

Many vines have no mature wood when the leaves have fallen in the autumn, while others again have some. While the spotted leaves may appear all over the vineyard, the diseased canes appear on vines in spots, these spots in the vineyard growing larger year after year. A dead vine may be seen in the midst of healthy ones, while a healthy vine, on the other hand, may remain in the midst of dead ones. It takes generally several years to kill the vines, and some varieties are hardier than others. Some Muscats may succumb in one year, while some will last for three years or more. The roots remain alive and healthy longer than any other part, and, when the top of the vine has already died, it is common to see the root send up a healthy sucker, which, however, in its turn, will become diseased and die. It is likely that the vines in some districts will suffer more than in others, and in places the vines may not become seriously injured by the disease.

The berries on badly diseased vines do not develop, but shrivel up or remain sour, and in some cases dry up entirely. In others, again, they acquire a mawkish taste, lose flavor and sweetness, and make only inferior or bad raisins. These many different characteristics of the plague depend evidently on the stage of infection. They do not follow each other in any certain succession, nor do they all appear on the same vine. Some vines show one face of the disease, other vines show another, and the observer must have been previously acquainted with the disease before he can readily recognize it.

Nature and Cause.

—The cause of the vine plague is not known. No deadly fungus has so far been found on the vine, nor has any other deadly parasite been found on the diseased vines. In California the vine plague has been studied by N. B. Pierce, of the Agricultural Department at Washington. He suggested once that the disease was of bacterial nature, but has not proved his theory, his investigations not yet being finished. Mr. E. Dowlen has also been investigating this disease, and at one time thought it caused by a fungus, which, however, was proved later by Dr. H. W. Harkness to belong to the non-injurious kind. No insects of any kind prey on the vines in sufficient numbers to cause the serious symptoms of the vine plague.[7] Whatever may be the true cause of the vine plague, certain it is that it resembles in its advent and spreading such diseases in men as cholera, yellow fever or the Oriental plague. The vine plague appears to be especially promoted by warm, moist air and rain, but it is not confined to damp places, nor has it as yet been ascertained in what relation it stands to locality and climate.

In California it first made its general appearance in Anaheim in Orange county, in the month of August, 1884, when vineyards of old Mission vines suddenly stopped growing, and the grapes failed to color and ripen, while many of the vines died the same year. The plague attacks in preference vines growing on poor, sandy or alkaline soil, or in vineyards underlaid with hardpan. The weak vines succumb the first of any. This is the reason why so many vineyardists doubt the existence of any particular disease, contributing the poor condition of the vineyard to anything else than the true cause.

N. B. Pierce, who has now spent a year in studying the vine plague, has found many similarities between it and the mal nero of Italy; but the descriptions of the foreign investigators are both contradictory and insufficient, and, without a personal investigation of the Italian or French vines, the identity of our vine plague with any foreign disease cannot be established. It is to be hoped that the United States Congress will make such investigations possible. At present we do not even know whether the vine plague is original in this country or whether it was imported from foreign countries. The general opinion in the first attacked district is that the disease was imported there with grapevines brought from Europe. So far I have not been able to ascertain when and by whom such vines were imported, but I am satisfied that in the course of time it will be found that foreign grapevines were imported to the vineyards where shortly afterwards this disease first appeared.

Damages.

—The damages caused by the vine plague may be summed up as follows: The leaves turn spotted and yellow, finally dry up and fall off. The canes fail to mature, or mature only in spots. Later in the fall, they die from the tips, which turn black and become brittle. The berries either dry up or shrivel up, and fail to mature, or at any rate become mawkish or bitter. The yield becomes less and less every year, although, the first year that the vines are touched by the disease, the yield is often unusually large. In severe cases the vine dies in from one to three years, but a few may linger longer.

Remedies.

—The vine plague has existed in this State for six or eight years, but as yet few, if any, efforts have been made to extinguish it, and only during the last year have any experiments been carried on. The solutions of bluestone and lime which many expected would prove beneficial to the vines attacked by the plague have, in my opinion, done little or no good. Spraying the vines when in full foliage with the I X L compound greatly benefits the vines, and proves a powerful stimulant and the best remedy yet employed.

LEAF-HOPPER (Erythroneura comes).

Characteristics.

—This pernicious little pest is a bug which multiplies in enormous quantities and sucks the sap out of the vine leaves. Many use the name of thrips to denote this insect, but this is incorrect, as the thrips is an entirely different, much smaller, insect, which so far has never been injurious to the vines of this coast. In size the leaf-hopper is, at maturity, about one-tenth of an inch. In color it is yellowish white, with a few red spots. When the insect approaches maturity, it jumps, but the undeveloped insect or larva only crawls, principally on the underside of the vine leaves, where their cast-off skins can be seen in all stages and sizes. The eggs are laid in the veins of the leaves. The glossy globules which are always seen on leaves where the leaf-hopper is found are not the eggs, as has been supposed by many, but is only the vomit which, when irritated, the hopper throws out either as a defense, or because it desires to rid itself of an unnecessary burden. The leaf-hopper hatches at least two times, or possibly three times, during the summer. Many of the insects remain over during winter time. They feed on almost anything, such as alfilerilla (Erodium), etc., but are especially fond of the grapevines, and even in the early spring flock onto the young vine shoots, leaving the less desirable weeds. In some localities this insect is known variously as the white fly, the vine-hopper, or incorrectly as the thrips.

Damages.

—The hopper punctures the leaves and causes them to dry up and fall, thus exposing the grapes to the hot sun. The excrement of the hoppers also covers the grapes largely, and spoils their appearance and keeping quality, at least as table grapes. It is principally the table grapes and wine grapes which are injured by this insect; the former are made unfit for shipment, and the latter do not color well when deprived of their leaves. If the grapevines are kept growing, the grapes are less injured, and some growers even contend that the hopper is advantageous, as it causes the leaves to fall and the grapes to mature.

Distribution.

—It is not known whether the leaf-hopper is a native of California, and I hardly believe it is. It does not exist in Southern California, but in Northern California and in the San Joaquin valley it is common. In the grape districts of Southern California there is found another variety of leaf-hopper almost twice the size and of a brilliant green color, which only once appeared in such quantity as to do any damage at all. Generally it is quite rare. The Erythroneura comes, however, occurs in countless numbers, and often rises in clouds when the vines are approached. In some years it is less common than in others, and after having been plentiful for several years gradually diminishes in quantity, but never disappears entirely.

Remedies.

—Pasturing the vineyards with sheep as soon as the grapes are picked is very beneficial. The sheep destroy both hoppers and leaves, and the following season always finds the hoppers greatly diminished in numbers. The sheep do no injury to low-pruned vines, and in Fresno many vineyardists pasture their vines regularly every year in October and November, or as soon as the grapes are picked and the vineyards are made accessible.

The gauze bell consists of a bell-shaped cover made of wire netting, large enough to cover the vine. The inside of the bell is sprayed with petroleum, and then turned over the vine. A shake is then given the vine, when many leaf-hoppers will fly up and stick in the petroleum. It will only pay to use this remedy on table grapes; for raisin grapes it is too expensive.

RED SPIDER.

Characteristics.

—Red or yellow mites are quite frequently injurious to grapevines. These mites are small, almost microscopical, and appear in enormous quantities on both sides of the leaves, especially, however, on their under side. They cover the leaves, and even the ground of the vineyard, with a thick cobweb, in which they live and hatch. Dry air and heat promote the wellbeing of the mites, and hasten the injury they do to the vine leaves, which soon dry up and check the growth of the vines. On the contrary, dew and moisture destroy the red mites in a short time, and in places near the coast they are seldom very injurious.

Remedies.

—Sprays of various kinds, such as whale-oil soap, resin sprays, etc., have been used. Frequent spraying with pure water will destroy the mites, but they will multiply again if the climate is favorable. The best success is had with a spray of a compound known as the I X L compound, which is used in the proportion of five pounds of the compound to thirty gallons of water. One good spray will destroy both the mites and their eggs.

CATERPILLARS.

Characteristics.

—The caterpillars which trouble the raisin grapes are confined to three or four kinds. The most common and also the most destructive are the very large larvæ of the sphinx moth. The common grapevine sphinx (Philampelus achæmon) is a large larva, incorrectly called a worm, which is, when full grown, over three inches long. The color varies from bluish green to brown, with several lighter stripes on each side. The head is truncate, and the tail is furnished with a curved horn. The pupa hibernates in the soil below the vines, and is about half the size of the full-grown caterpillar. The full-grown moth is about two inches long by two and one-half inches between the outstretched wings. The eggs are laid by the moths on the leaves of the vines. Two broods of caterpillars appear yearly under favorable conditions, or else only one brood, which generally appears in the end of July. The caterpillars grow with great rapidity, and attain their full size in a few weeks. The pupæ hibernate in the soil and hatch the following summer.

Another large grapevine caterpillar is the Deilephila striata, which is about the same size as the Achæmon. The moth has more pointed wings, with narrow stripes, and the larva is brighter colored, often yellowish green, with several colored stripes on the sides. The eggs are not laid on the vines, but on the weeds on the vacant lands outside the vineyard, especially on species of Epilobium, but also on other weeds, and they hatch and feed on them. The caterpillars feed in ordinary years only on the weeds on which they are bred, but in other years which are especially favorable to their enormous increase they migrate to the vineyards and feed on the vines at the most alarming rate. The caterpillars of both the above large moths vary in color from green to brown or violet brown, but as a rule the Deilephila is more brightly colored than the Achæmon. The former is more active and often travels in enormous numbers, when it is called the army-worm. The Achæmon is more blunt at both extremities, the head being almost truncate.