|Prunus armeniaca subsp. var.||Apricot|
|Standard Cyclopedia of Horticulture|
Apricot. Rosàceae. A tree and fruit somewhat intermediate between the peach and the plum, grown largely in California and in special localities in the East.
The apricot tree is a round-headed grower, with dark, somewhat peach-like bark, and very broad or almost circular leaves. The fruit, which usually ripens in advance of both the peach and plum, is peach-like in shape and color, with a smoother skin, rich yellow flesh and large flat smooth stone. The flesh is commonly less juicy than that of the peach, and, as a rule, perhaps, of higher quality. The apricots are of three species, all probably native of China or Japan. (1) The common apricot of Europe and America is Prunus Armeniaca: fr. variable, but smooth at maturity, red or yellow, the sweet and firm flesh free, or very nearly so, from the large, smooth, flat stone: tree with a round, spreading too, and a reddish, cherry-like or peach-like bark: lvs. (Fig. 279, right) ovate or round-ovate, with a short point and sometimes a heart-shaped base, thin and bright green, smooth or very nearly so below, as are the gland-bearing stalks, the margins rather obtusely and mostly finely serrate: fls. pink-white and borne singly, sessile or very nearly so, preceding the Lvs. (Fig. 280). The Russian apricot is a hardy but smaller-fruited race of this species. (2) The Japanese apricot, in Japan grown for flowers rather than for fruit, is Prunus Mume: fr. small, yellowish or greenish, the flesh rather hard and dry, and adhering tightly to the pitted stone: tree like the common apricot, but with a grayer or greener bark and duller foliage: Lvs. grayish green, generally narrower (Fig. 279, left) and long- pointed, more or less hairy along the veins below and on the shorter mostly glandless stalk, thick in texture and prominently netted beneath: fls. fragrant, borne singly or in 2's, and sessile (without stalks) ; more lately intro. into this country, chiefly under the name of Bungoume plum. (3) The third species is the purple or black apricot, Prunus dasycarpa, which is little cult. : fr. globular and somewhat plum- like, with a distinct st., pubescent or fuzzy even at maturity, dull dark purple, the sourish soft flesh clinging to the plum-like fuzzy stone: tree round-headed, with much the habit of the common apricot, with Lvs. ovate and more or less tapering at both ends, thin, dull green, on slender and pubescent, mostly glandless, stalks, finely appressed-serrate and hairy on the veins below: fls. large and plum-like, blush, solitary or in 2's, on pubescent stalks ½ in. or more long, and appearing in advance of the leaves. See Prunus for related species. The apricot-plum, Prunus Simonii, is discussed under Plum. The plumcot is a hybrid of plum and apricot, accounted for under Prunus.
East of the Mississippi the apricot is not grown commercially to great extent, although it is a popular fruit for the home orchard and garden. As a commercial crop, it does not seem to be increasing in favor. There are two important reasons for this: the loss of the fruit by spring frosts because of the very early season of bloom, and the great liability to curculio attack.
Possibly the apricot has not yet been given a thorough test. Its value may be more appreciated and the difficulties of its culture lessened when the fruit has received greater study and attention. The apricot is as hardy as the peach and thrives in similar localities and under the same general cultivation and treatment, but demands very strong soil. The ideal land for this fruit seems to be one that is deep and dry, and loamy or gravelly in character. The rolling loamy lands that are well adapted to apples seem to be well suited to the apricot, if the exposure and location are correct. The apricot is particularly impatient of wet feet, and many of the failures are due to retentive subsoils. The kind of soil has an important bearing also on the stock to be used.
Particular attention should be given to the location and exposure of the apricot orchard. In the East the best results are secured if the plantation stands on elevated land near a large body of water, for there the spring frosts are not so serious as elsewhere. Generally a somewhat backward exposure, if it can be had, is desirable, to retard blooming. Apricots will be sure to fail in frosty localities.
The apricot should always be given clean culture. For the first two or three years, some hoed crop may be grown between the rows, but after that the trees should be allowed the entire land, particularly if set less than 20 feet apart. Tillage should be stopped late in summer or early in fall to allow the wood to mature thoroughly. It is best to raise a cover-crop in the latter part of July or in August to hasten this maturity and also to protect the roots and to improve the physical properties of the soil. The trees are pruned in essentially the same way as plums. The fruit-buds are borne both on spurs (two are shown in Fig. 281) and also on the wood of the last season's growth on either side of the leaf-bud, as shown in the twin and triplet buds above a in Fig. 281. Each bud contains a single naked flower (Fig. 280). As the fruit begins to swell, the calyx-ring is forced off over the top (Fig. 282) and the injury from curculio may then be expected. The fruit is often borne so close together as to appear to be in clusters (Fig. 283).
When grown under the best conditions, the apricot may be considered to be nearly or quite as productive as the peach. Like other fruit trees, it bears in alternate years, unless the crops are very heavily thinned. It can never be recommended for general or indiscriminate planting. Only the best fruit-growers can succeed with it. Apricots are to be considered as a dessert or fancy fruit, and therefore, should be neatly packed in email and tasty packages.
The varieties mostly in demand in the eastern states in order of preference are: Moorpark, Harris, Alexis, Montgamet, Budd, Early Golden, St. Ambroise, Alexander and Peach. The Royal and Superb are grown to some extent. Of the above-mentioned varieties, the Harris, St. Ambroise, Montgamet, and Early Golden are early as regards season of ripening; the Peach and Moorpark are medium; the Alexander, Alexis and Budd are late. The Alexander, Alexis, Budd and some others belong to the Russian race. Fig. 284 shows a good-shaped apricot.
The apricot is propagated by budding or grafting the desired varieties on the peach or plum stock. On its own root the apricot seems to be less successful, probably because of the peculiar soil-requirements that it demands. The peach seems to give a better union and consequently a better stand, whereas the plum stock gives a tree that is hardier, longer lived, and less subject to attacks of borers. Both Myrobalan and Domestica stocks are used, the preference being for the latter.
The most serious enemy of the apricot is the curculio, the same insect that attacks the fruits of plum and peach. This insect seems to have a particular fondness for the apricot, and as the fruit sets very early, the crop may be expected to be destroyed unless the most vigilant means are employed. The foliage of the apricot, as in the case of the peach, is especially sensitive to the arsenical sprays and therefore entomologists nave hesitated to recommend paris green and arsenate of lead for the control of the curculio. The work of W. M. Scott and A. L. Quaintance, of the United States Department of Agriculture, has shown, however, that arsenate of lead in combination with self- boiled lime-sulfur is successful in controlling this pest on the peach. It is probable that the mixture will be equally successful in controlling the curculio on the apricot. They recommend the use of two pounds of arsenate of lead combined with fifty gallons of self- boiled lime-sulfur applied as follows:
First application.—About the time the calyces, or shucks, are shedding from the young fruit. Second application.—Two or three weeks later, or about one month after the falling of the petals. Another method of control of this insect is by jarring the trees, in the same way as with plums and peaches, but the work must be even more thoroughly done than with those fruits. The jarring should begin as soon as the blossoms fall, and continue as long as the insects are numerous enough to do serious damage. It will usually be necessary to catch the insects for three to six weeks, two or three times a week, or perhaps even every day. The work must be performed early in the morning, while the curculio is indisposed to fly. The operation consists in knocking the insects from the tree by a quick jar or shake, catching them on a white sheet or in a canvas hopper. The catcher formerly used in western New York was a strong cloth hopper mounted on a wheelbarrow-like frame, and run on two wheels. The hopper converged into a tin box, into which the curculios rolled as they fell on the sheet. One man wheeled the device, by barrow-like handles, under the tree, then dropped the handles and jarred the tree; or sometimes two men went with a machine, one wheeling it and the other jarring the trees. If the work of spraying, as above recommended, is done thoroughly, it will probably not be necessary to use this jarring device in addition; and the device is now going out of use.
The apricot is often trained on walls, where the fruit reaches the highest perfection. Care should be taken that the wall does not face the east or the south, or the early-forced flowers may be caught by frost. An over- hanging-cornice will aid greatly in protecting from frost.
The apricot in California is one of the leading commercial fruits. It was apparently introduced by the Mission Fathers, for Vancouver found it at the Santa Clara Mission in 1792. However, there is no relation between this early introduction and the expansion that quickly followed the American occupation, because the Mission Fathers had only seedling fruits, while the early American planters, shortly before the gold discovery, introduced the best French and English varieties, and were delighted to find that these sorts, usually given some protection in the Old World, grew with surprising thrift of tree and size of fruit in valley situations in California in the open air. Upon these facts the apricot rose to wide popularity. The acreage has steadily increased during the last fifty years, and with particularly swift rate during the last twenty years, until the number of trees reported in 1899 was about three millions, occupying upwards of forty thousand acres of land. Since then, however, the acreage has not increased, because the crop is irregular on account of frost injuries in some districts. The fruit is sold fresh, canned, dried and in crystallized forms, in all the regions of the United States, in England and on the Continent, where, by reason of its superior size and acceptable manner of curing, it has achieved notable popularity. The year 1905 was the greatest thus far in amount of dried product realized, viz., 36,000,000 pounds. The year 1911 was greatest in amount of canned product, which reached upwards of 758,325 cases, each containing two dozen 2½-pound cans. The shipment of fresh apricots out of California during the summer of 1910 was 290 carloads.
The chief part of the apricot crop of California is grown in the interior valleys. In the low places in these valleys, however, the fruit is liable to be injured and sometimes almost wholly destroyed by spring frosts, although the trees make excellent growth. In foothill situations adjacent to these valleys, there is also serious danger of frost above an elevation of about 1,500 feet above sea-level, and the tree is rarely planted for commercial purposes. In southern California the apricot succeeds both in the coast and interior valleys. But along the coast northward, excepting the very important producing regions of the Alameda and Santa Clara valleys, eastward, and southward from the Bay of San Francisco, the apricot is but little grown, owing to frost troubles. In respect to these, the apricot is somewhat less subject to harm than the almond, but it is less hardy than the peach, and has, therefore, a much narrower range of adaptation. The average date of the blooming of apricot varieties is about two weeks later than that of the almonds. The apricot is adapted to a wide range of soils, because to the rather heavy, moist loams which its own root tolerates, it adds the lighter tastes of the peach root, upon which it is very largely propagated. However, attempts to carry the apricot upon heavier, moister soils by working it upon the plum root have not been very successful, owing to the dwarfing of the tree; and the movement toward the light, dry loams, by working upon the almond root, has failed because the attachment is insecure, and the trees are very liable to be snapped off at the joining, even though they may attain bearing age before the mishap occurs. The apricot root itself is a favorite morsel with rodents, and is for that reason not largely used. The mainstay for the apricot, then, is the peach root, and the soils which this root enjoys in localities sufficiently frost-free are, therefore, to a great extent the measure of the apricot area.
Apricot trees are produced by budding on peach or apricot seedlings during their first summer's growth in the nursery row, from pits planted when t lie ground is moist and warm, at any time in the preceding winter. When there is a great demand for trees, planting in orchard is sometimes done with dormant buds, but ordinarily the trees are allowed to make one summer's growth in the nursery. The trees branch during the first year's growth from the bud, and usually come to the planter with a good choice of low-starting branches, from which to shape the low-headed tree which is universally preferred. The method of securing such a tree is identical with that already described for the almond, but the treatment of the tree after reaching bearing age, in its third year, is very different from the after-treatment of the almond. The apricot is a rampant grower and most profuse bearer. Unless kept continually in check it will quickly rush out of reach, and will destroy its low shoots and spurs by the dense shade of its .thick, beautiful foliage. There is continually necessary, then, a certain degree of thinning of the surplus shoots and shortening of the new growth, to continue the system of low branching, to relieve the tree from an excess of bearing wood, and to avoid small fruit and exhaustion of the tree, resulting in alternate years of bearing. In the coast regions, where the tree makes moderate wood- growth, it can be kept in good form and bearing by regular winter pruning. In warmer regions, where the tendency is to exuberant wood-growth, the main pruning is done in the summer, immediately after the fruit is gathered. This has a tendency to check wood- growth and promote fruit-bearing, and where the main cutting is done in the summer, winter pruning is reduced to thinning out shoots, to prevent the tree from becoming too dense and to lessen the work of hand-thinning of the fruit later on. In addition, however, to the most intelligent pruning, much fruit must be removed by hand when there is a heavy set of it, in order to bring the fruit to a size satisfactory to shippers or canners, and to reach the highest grades, if drying is practised. California apricot orchards are all grown with clean tillage, for the main purpose of moisture conservation. In regions of good rainfall and sufficiently retentive loams no irrigation is required; good tillage will suffice for the production of large fruit and perfection of fruit-buds for the following year. As the trees are becoming older and bearing larger crops the demand for moisture increases, and the use of irrigation water is growing. In most places, however, one irrigation is sufficient, and that is given after fruit-gathering, to carry the tree through the last half of its season's work. In the regularly irrigated regions of the state, water is periodically applied through the growing season, in such amount and at such intervals as the local climate and soils require.
Although probably all the good varieties of the apricot in the world have been introduced into California in the last half-century, and scores of selected seedlings of local origin have been widely tested, the varieties that have survived the tests and are now widely grown are comparatively few in number. Most of the rejected varieties met this fate because of shy bearing, and those which now constitute the bulk of the crop are very regular and full bearers, under rational treatment. A local seedling, the Pringle, was for many years chiefly grown for the earliest ripening, but this has recently been largely superseded by another local seedling, the Newcastle, which is of superior size and about as early. The European varieties, Large Early and Early Golden, are fine in a few localities where they bear well, and do better in southern California than elsewhere. The universal favorite is the Royal; probably three-fourths of all the trees in the state are of this variety, though recently the area of the Blenheim has been increasing largely. The Hemskirk stands next to the Blenheim in popularity. The Peach is largely grown in the Sacramento Valley. The best apricot grown in California is the Moorpark; in size and lusciousness, when well ripened, it heads the list. It is, however, rather shy in bearing, and is forsaken for this fault in most regions. It shows the best behavior in the Santa Clara Valley, and is there retained, in spite of frequent lapses, because of the high prices which it commands at the canneries. About a dozen other varieties are carried in small number by the nurserymen to meet limited local demands.
Apricots for canning and drying are graded according to size: Extra, not less than 2¼ inches in diameter; No. 1, 2 inches; No. 2, 1½ inches; No. 3, 1 inch. The first three grades must be sound, clean and free from blemish, and No. 3 must be of good merchantable quality. The shippers and canners require well-colored but only firm-ripe fruit, because both the long rail transportation and the canning process require it; soft-ripe fruit will neither can nor carry. For drying, riper fruit is used, and yet over-ripeness has to be guarded against to avoid too dark color. For canning, the fruit must be carefully hand-picked; for drying, much is shaken from the trees. The drying process consists in cutting the fruit in halves longitudinally, dropping out the pits and placing the halves, cavity uppermost, upon light wooden trays. Breaking or tearing the fruit open will not do; it must show clean-cut edges. When the trays are covered they are placed in a tight compartment, usually called a "sulfur box," though it may be of considerable size, and the fruit is exposed to the fumes of slowly burning sulfur, to ensure its drying to the light golden color which is most acceptable to the trade. The production of the right color is the end in view, and different dryers regulate the amount of sulfur and the length of exposure according to the condition of their fruit and their judgment of what it needs. The exposure varies from half an hour to two or three hours, according to circumstances. After sulfuring, the trays are taken to open ground, and the fruit is cured in the sun. Only a very small fraction of the California product of evaporated apricots is cured in an evaporator. It requires about six pounds of fresh apricots to make one pound of cured fruit.
A moderate estimate of the yield of apricots might be placed at seven and one-half tons to the acre; extreme yields are far away from this both ways.
The apricot is, as a rule, a very healthy tree in California. It is, however, subject to injury by scale insects of the lecanium group in some parts of the state. During recent years there has been increasing injury by a shot-hole fungus, which perforates the leaves and makes ugly pustules upon the fruit. Such fruit is unfit for canning except the fruit be peeled, which is little done as yet. It also makes low-grade dried product. This fungus can be repressed by fungicides of the copper class.
Common Apricot. Small round-topped tree with reddish bark much like that of the peach tree: lvs. ovate to round-ovate, sometimes slightly cordate at the base, abruptly short-pointed, glabrous (at least above), closely serrate, the stalks stout and gland-bearing: fls. pinkish, solitary and sessile or very nearly so, appearing from lateral buds of last year's growth (sometimes on short year-old spurs) before the lvs.: fr. variable, nearly smooth when ripe, short-stalked like a peach, usually somewhat flattened, mostly yellow and overlaid more or less with red, the stone flat and smooth, ridged or sulcate on one edge. Probably Siberia (Dahuria, Manchuria) to China as a native plant. It early reached Eu., where it was once supposed to be native of Armenia, whence the name Armeniaca. The Russian apricot is a hardy race of this species. Var. pendula, Dipp., has hanging or pendulous twigs. Var. variegata, Hort., has white-variegated foliage.—P. Armeniaca is apparently widespread in farther Asia and it is variable. By some authors the main forms are separated as species but the differences appear to be too unimportant or inconstant for clear definition and they are here retained as varieties.CH
Grafting for true offspring. Seed. Apricot cultivars are most often grafted on plum or peach rootstocks.
Pests and diseases
Susceptible to bacterial canker and blast, bacterial spot and crown gall. Susceptible to fungal diseases such as brown rot, Alternaria spot and fruit rot, and powdery mildew. Nematodes and viral diseases, can also be a problem, including graft-transmissible problems.
Apricots and plums can hybridize with each other and produce fruit that are variously called pluots, plumcots, or apriums.
Var. sibirica, Koch (P. sibirica, Linn. Armeniaca sibirica, Pers.).Siberian Apricot. Bush or small tree, 10 or 12 ft. high: lvs. small and glabrous, or sometimes sparingly bearded beneath, ovate to rounded, long- pointed, unequally crenate-serrate: fls. white or pink, appearing early in the season and usually in great profusion, subsessile, the calyx minutely puberulent: fr. globular, rarely more than 1/2in. diam., vellow with a reddish cheek, scarcely fleshy, practically inedible, finally splitting; stone smooth, very sharp-edged. Mongolia, Dahuria. L.B.C. 17:1627.—Sometimes planted as an ornamental bush.CH
Var. mandshurica, Maxim. (P. mandshurica, Koehne). Lvs. rounded, subcordate or cuneate at base, at apex long-cuspidate and acute, margin strongly double-toothed, the teeth sharp and twice longer than wide: peduncle long (about 1/4 in.): fr. nearly globular, scarcely 1 in. long, yellow, red-spotted, succulent and sweet; stone small and smooth, the margin obtuse, the seed sweet. Manchuria.—Distinguished by the narrow sharp teeth and double serration of the lvs. ; kept as a distinct species by some authors.CH
Var. Ansu, Maxim. (P. Ansu, Komar.). Lvs. broad- elliptic, at base short-cuneate, at apex acuminate, very glabrous, the margins crenate-serrate: peduncles hispid: fls. twin: fr. subglobose, deeply umbilicate or sulcate, red, tomentose, the flesh grayish brown and sweet and free from the minutely reticulated stone which has one very sharp edge. Japan; cult.—Retained as a separate species by some, being marked by the cuneate base of the lf.CH