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

by Gustavus A. Eisen

—The vines are set at various distances, in some places four feet each way, in others again six by ten, giving a various number of from 740 to 2,622 to the acre. In some places, the old practice of planting the vines in groups of four still exists. Each group consists of four vines one and a half feet apart, and each group distant six feet from each other either way. Of late, however, the vines are planted farther apart, probably because the soil is becoming exhausted, a favorite way being to have the vines closer one way than the other.

Care of Cuttings, Planting and Grafting.

—Great importance is attached to procuring cuttings from a distance, or in getting new strains. Cuttings from the nearest vineyard are never used, as they are considered to produce inferior vines, and not do as well. To procure cuttings or vines, the old vines are sometimes cut a few inches below the surface of the soil, causing the parent plant to throw off numerous suckers or shoots, which the following winter are separated and used as we do rooted vines here in California. Three or four years will elapse before they come into regular bearing. Some vineyards are produced by grafting the black currant on the wine grape, and many wine vineyards that do not pay are thus transformed into paying raisin vineyards. The grafted vines come into bearing much sooner than those grown from cuttings. The grafting is performed in Zante as follows: The soil is dug away from the main trunk of the old vine to the depth of from twelve to eighteen inches, and the trunk cut off square at the bottom of the pit. Two or three scions are then inserted in the trunk, and made to slightly project above the ground, in no case with more than two or three eyes. Clay is then applied to the joint of the graft, and the trunk slightly covered with leaves, and the hole then filled up with soil. The grafting is done in the spring, and the cuttings must be kept dormant in dark and cool cellars.

Pruning the Vines.

—The pruning is done in the fall, just as soon as the leaves have fallen, and is performed in two parts. In December, the vines are cleaned of all small, weakly or dead branches, and at that time only the large and strong branches are left. In February, the regular cutting back commences, two or three eyes being left on every spur. There are as many different ideas of pruning the vines in Greece as there are in California, each one having his favorite methods and theories as to what is proper and what is not. Some vineyardists prefer to delay the second pruning until after the vines have started to bud out, and, when the young shoots are two weeks old, the old wood is so cut that the bleeding of the vine will not run down on the bud. Bleeding is at any time considered injurious. The principal pruning is therefore conducted in February, as being the time most suitable to the currant grape and conducive to the best crops. Mr. Manoti, a very intelligent Zanteote currant grower, told Dr. Davy (Ionian Islands, page 343) that he had at one time experimented with pruning the currant vine at different times of the year. Those pruned in December yielded very few grapes, which were large; those pruned in April gave plenty, but very small berries. Again, those pruned in February were in every way the best. Mr. Manoti added that if he had told one of his neighbors of his experiments they would have laughed at him, and said, “Whoever thinks of pruning the uva passa (or currant) in December or April.” This shows how much the growers are opposed to experimenting and improving upon the methods which have been handed down to them from their forefathers. As we have shown, the currant vines are all very closely pruned, very much in the same way as our Muscats. Seldom more than three spurs are allowed to remain, each one with two or three eyes. Summer pruning or topping the branches is never practiced on the currant vines, but generally on the wine grapes. On the contrary the currant branches are carefully guarded, and in order that they may not break are tied to stakes from four to five feet high.

Care of the Vineyard.

—After irrigation is over, the vineyards are dug over. The soil is dug up around the vines and placed on top of the ground in small heaps, which process is considered beneficial both to the roots of the vines and to the soil. In April, this soil is all put back, and the ground leveled. Each vine is staked. By the middle of April, the vines are in leaf. By the middle of July, the first fruit is ripe, and by the middle of August the harvest has everywhere begun. The stakes for the vines are imported at a cost of $15 or $16 per thousand, and constitute the most expensive item in the construction of a currant vineyard.

The mildew or oidium, which some fifty years ago spread all over the world, destroyed many of the vineyards before the sulphuring was discovered as a sure remedy. Sulphuring the vines is now regularly practiced in all the vineyards; but there is a popular belief that the raisins are no longer of the same fine and pure flavor as they used to be before the advent of the oidium and the sulphur.

Ringing the Branches.

—A process much used in the currant vineyards is the ringing of the branches. At the time of blossoming, some of the main branches are cut in such a way that a small ring of bark is separated from the branch near its base. The sap which ascends in the interior of the branch, but which returns by the bark, is thus prevented from returning, and must remain in the branch. The effect is that a large number of clusters are formed with berries both larger and sweeter than those not thus treated. But the practice is not without its drawbacks. In the dry lands of Cephalonia, where it was first introduced, it was soon discovered that the ringed vines began to fail after two or three years, and the method had to be modified or abandoned. In Morea, where the soil is moister and richer, the ringing did not prove as dangerous, and is yet practiced, though great care is taken that the same branch is never girdled or ringed in two successive years. Only the strongest vines are able to resist the exhausting effects of the process; the weaker ones should never be forced to overproduce.