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

by Gustavus A. Eisen

Extent and Location.

—The Fresno district contains about thirty thousand acres, out of which about twelve thousand are in good or full bearing. Merced county has about two thousand acres, nearly all very young vines. Kern county has probably about one thousand acres, also very young vines, and some thirty acres of old vines. Tulare county has about seven thousand acres of Muscats, a large part of which is in full or good bearing. Many vineyards, large and small, are being planted in these counties this year, but enough attention is not paid to proper soil and to locality, and here, as elsewhere in the State, many of these vineyards will not turn out as the owners expect they will. In Fresno county, the old vineyards are planted principally around Fresno City, while in late years other raisin districts or sub-districts are growing into prominence around Malaga, Sanger, Selma, Fowler and Madera. The varieties used are principally the Gordo Blanco Muscatel, much mixed with the Muscat of Alexandria. There are some few acres of Sultanas and White Corinths, and of late many Malagas have been planted.

Soils and Climate.

—There are several different varieties of soils in the district,—the red or chocolate-colored sandy loam principally east of the railroad, the white, ashy soil west of the railroad, and the very sandy soil, generally occurring in elevated ridges. We have also the deep, gray-colored bottom land in the river bottoms or along the rivers and creeks. The best grades of the chocolate and reddish loams, and of the river bottom soil, is considered the best for raisins. The very sandy soil and the alkali soil should not be used for raisin purposes. The climate is warm and dry during the summer, while the winters are not very rainy. From seven to ten inches of rain are an average in Fresno; south to Kern the rainfall decreases, five and a half inches being an average around Delano. Towards the northern end of the valley, the rainfall increases, and in Merced county varies between ten and twenty inches, fifteen inches being a high average. In no portion of the raisin-producing portion of the valley can raisin grapes be grown without irrigation, the natural rainfall being entirely insufficient. The lowest temperature is about eighteen degrees Fahrenheit in Fresno, generally in January, while the highest is one hundred and eighteen degrees Fahrenheit in the shade in July and August. The lowest temperature is reached once in from three to five years, and the highest quoted is similarly scarce. The high average in summer time is one hundred and ten in the shade, and for three months of the year the thermometer every day can be counted on to vary between one hundred and one hundred and ten in the shade. In the winter, twenty degrees Fahrenheit is often reached, and the end of December and January may be counted on as being cold and frosty. These figures all refer to the level plain land, where the most of the vineyards are planted, and not to the foothills or the thermal belt, nor to the high Sierra Nevada, where snow and ice are common, and where glaciers cover many of the highest mountain peaks. The most rainfall occurs from December to February, and the rain continues more or less scattering to April and May. There is only very seldom a shower in the summer, one perhaps in three years. In the mountains, the fall rains commence about the middle of August, on the plains again in October and November, sometimes even later. Dew is rare in summer time, but common from the beginning of October. Fog is rare, sometimes an unwelcome visitor in November, but never known at any other time of the year. Spring frosts are almost unknown, and occur only once in from five to eight years.

Irrigation.

—Irrigation is practiced wherever raisins are grown. The water is taken from the rivers,—from Kings river in the Fresno district, and from the Merced, Kaweah and Kern rivers, etc., in the other districts. Before irrigation was begun in the Fresno districts, there were from fifty to sixty feet of dry soil before the natural water level was reached; but this has been so changed through a few years of constant irrigation, that now in places the land is subirrigated or moist to the surface, while in places even the soil requires to be drained, and no other irrigation is now needed except to allow the water to flow in the main or secondary canals, from which it seeps and keeps the soil filled with water, the moisture rising from below. The irrigation when practiced is done by flooding or by irrigating in furrows. New land must be irrigated until it becomes subirrigated; but, when once this is done, no separate irrigation becomes necessary. Many vineyards planted on subirrigated land which was once dry land have never since been irrigated.

The Vineyard.

—The general distance of the vines is eight by eight or ten by ten feet, varying in different vineyards. Of late, there have been some efforts made to improve upon these distances, and to have them planted closer one way than the other, say five by ten or six by twelve feet. The vines begin to bear the second and third years, and if planted on proper soil should pay the fourth year and give an income the fifth year. Some vines have been known to pay the third year, there being much difference in this respect. Both cuttings and rooted vines are used, rooted vines having been preferred during the last few years. The ground is plowed in various ways in the winter time, according to the ideas of the owner. Cross-plowing is sometimes practiced. The general rule is to first plow one way, and then to cross-cultivate repeatedly until the soil is level and the weeds are destroyed. In wet places, the cultivation is kept up until July, but in proper places the working of the soil is finished in the early part of June.

Pruning and Other Operations.

—The heads of the vines are kept low,—from six to sixteen inches above the ground. The canes are cut to two or three eyes, and the number of canes left vary from five to fifteen or more. The pruning is done between December and February. Summer pruning is practiced by some, but not by all growers, there being considerable difference of opinion as to the value of this operation. Sulphuring is practiced by all growers, some sulphuring only once, but the best vineyards are sulphured three or more times. Oidium or mildew never appears in sulphured vineyards. Some few growers sulphur with great success against the colure or dropping of the grapes. Leaf-hoppers are common, but do no great harm. Grasshoppers and grape caterpillars were troublesome one or two seasons, but have not reappeared of late. Black-knot is common in many places.