Читать книгу The Nut Culturist - Andrew S. Fuller - Страница 8

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Almonds are usually divided into three groups, viz.: Bitter, hard-shelled, and soft, or paper-shelled. In each there are many varieties, although they are rarely known in market except by the general name of the group to which they belong. If they are soft, hard or bitter, this is sufficient designation for commercial purposes, with, perhaps, the addition of the name of country in which they were grown, or that of the city or seaport from whence exported.

Bitter Almond, Amygdalus communis amara.—The varieties of this group are not specifically distinct, and some have soft, thin shells, while others are thick and hard; but the kernels are very bitter, hence the name. But in the countries where these almonds are most extensively cultivated, as in the South of France, Austria, Spain and Greece, the trees are generally raised from the nut, and, as might be expected, the crop produced under such conditions is exceedingly variable, the nuts being large or small, and the shells of various degrees of hardness, with an occasional tree producing both bitter and sweet kerneled nuts. These wilding trees are, in the main, more hardy than the improved varieties, hence are largely employed as stocks for the better sorts, as well as for the plum and apricot. It is also claimed that, as a rule, the bitter almond trees bloom later in the spring than those of the other two groups, and for this reason are not so liable to be injured by spring frosts. The trees are hardy in all of our most favorable peach-growing regions of the Middle and Northern States, but some of the varieties ripen rather too late for localities north of the latitude of New York city. All this, however, and other obstacles, will soon disappear, whenever the time arrives for our horticulturists to take up almond culture and pursue it with half the zeal they have the cultivation of the peach and many other kinds of fruits.

Hard-Shelled Almond, A. c. dulcis, or sweet-kerneled almond.—The varieties of this group, as a whole, differ from those of the next only in the firmness of their shells, which are moderately firm, with a slightly rough and deeply pitted surface, as shown in Fig. 7. Varieties of this group are fully as large as, and perhaps a little longer than the thin-shelled, and the kernels are fully as valuable when removed and sold as shelled almonds. It may require a little more labor to crack and remove the kernels for market, but the difference is scarcely worth taking into consideration by the grower.

The common sweet, hard-shelled almond thrives in peach-growing regions as far north as Central New York, and I well remember of seeing trees loaded with these nuts, in my boyhood days, in the western part of the State. The late Patrick Barry, in the Fruit Garden, when referring to this nut, says:

"This is a hardy and productive tree, succeeding well in the climate of Western New York, and still farther north. Nut very large, with a hard shell and a large sweet kernel; ripe here (Rochester) about the first of October. The tree is very vigorous, has smooth, glaucous leaves, and when in bloom in the spring is more brilliant and showy than any other fruit tree."

FIG. 7. HARD-SHELLED ALMOND.

Nearly every one of our noted horticulturists who have said anything about almond culture in the North, agree with Mr. Barry in regard to the beauty of this tree and its productiveness; but it is well to keep in mind that it is no more to be depended upon than the peach, and the barren years will far outnumber the bearing ones. But the almond is probably as certain here as in France, where it is cultivated extensively as an article of commerce, although a full crop once in about five years is about all that is expected. We can probably do much better than this, especially if proper attention is given to the production of new varieties adapted to our climate, as has been done in California with the almond, and here in the East with the peach and many other kinds of fruits; and when such have been secured, proceed to multiply them in the usual mode of budding upon seedling stocks.

Soft, or Brittle-Shelled, A. c. fragilis.—In this group we have many distinct varieties, besides others which are known by local names, but have no permanent and pronounced distinguishing characteristics that would aid in separating them, should this be desired. The most common form, widely known as the sweet-kerneled thin-shelled (Fig. 8), is one of the oldest in cultivation in European countries. The flowers usually appear with the leaves, or before they unfold, and are large and of a pale rose color. The tree is rather tender for latitudes north of Philadelphia, but succeeds southward, and westward to the Pacific, if late frosts do not come to destroy the flowers or embryo nuts.

FIG. 8. THIN-SHELLED ALMOND.

Large Fruited Almond, A. c. macrocarpa.—This is an old French variety, and perhaps most widely known as the Sultana, although the latter name is often applied in market to almost every variety of sweet almond. The leaves of the genuine variety are much broader than those of the preceding groups, and are smooth and deep green. Flowers very large and showy, of a pale rose color, and always appear in spring before the leaves, and for this reason it has long been cultivated in England as an ornamental tree. Fruit large, depressed or flattened at the base, but pointed at the top. Shell rather hard and firm, and will withstand rough handling and transportation long distances. Kernel very sweet and tender, hence highly prized everywhere. There are several sub-varieties; one, known as the Pistache almond, is highly esteemed for the table, on account of its delicate flavor, although it is very small and not popular for commercial purposes.

The Peach Almond, A. c. persicoides.—This is another old variety, described by Du Hamel about the middle of the last century, under the name of Amandier-Pecher, or peach-leaved almond. Leaves similar to those of the common peach. Fruit ovate, obtuse; husk slightly succulent; shell of a yellowish color, and the kernel sweet-flavored and excellent. Du Hamel says the fruit varies widely, even upon the same tree or branch, some having a dry, thin husk, while on others it is soft and fleshy, somewhat like that of the peach. As the almond and peach are of the same species, it would not be at all strange if an occasional variety raised from the seed of either class should diverge towards, or even pass completely over to a closely allied group.

From the varieties found in the forementioned groups we must seek to find, or produce therefrom, those which will succeed in this country wherever it may be thought desirable to attempt the cultivation of this nut. So far as my knowledge extends, no attempts have, as yet, been made to produce distinct American varieties in the Eastern States, as with its near relative, the peach, but all the almonds thus far cultivated here are of well-known foreign varieties. Perhaps the demand for almond trees has not been sufficient heretofore to encourage very extended experiments in this direction, but I cannot believe that our people will continue for another century to import millions of pounds annually of almonds if it is possible to raise them in this country. That it is possible on the Pacific coast has already been fully demonstrated, but we want to see the field greatly enlarged, and give the people of the Eastern States a share in what is evidently soon to become a large and profitable industry.

Ornamental Varieties of the Almond.—These are only referred to because some of the many in cultivation belong to the groups producing the most valuable nuts, but the greater part of the purely ornamental varieties are worthless for other purposes. Amygdalus cochinchinensis grows to quite a large tree in its native country, or thirty to forty feet high; flowers small, white, produced in long racemes; tender. A. orientalis, a small shrub, with grayish or hoary leaves, and small rose-colored flowers; sometimes cultivated under the name of argentea, or Silvery almond. A. incana (hoary) is another dwarf species, from the Caucasus, with solitary red flowers. A. nana and A. pumila are oriental species of very dwarf shrubs, with either red or white flowers. The double-flowering varieties of these have long been inhabitants of our gardens.

Properties and Uses.—For domestic purposes the almond is highly esteemed wherever it is known, and is employed in hundreds of different ways in the preparation of appetizing dishes and dainties for the table. In countries where this nut is in cultivation, it is brought to the table in the half-opened green husk, for at this time the kernels are just passing from the milky stage, and are considered more readily digested than later, or when fully ripe. But it is only when they are fully mature that they are gathered for market, and after thorough drying they are placed in strong sacks and distributed among dealers in all parts of the world. But only certain varieties are exported in this condition, and principally those with very thin shells, because these are most in demand, for the table and dessert, where the almond is not a home product. Other sweet varieties, whether with very hard or very tender shells, are cracked and only the kernels exported. The importation of shelled almonds into this country is somewhat in excess of the unshelled, and as they are of greater value per pound, the duty levied is proportionally higher. There is also a great saving to the importer and consumer—not only in freight, but the extraction of the kernels is done in countries where labor is abundant and cheap. Whether the almond shells are used for any purpose in European countries, or are considered as wholly a waste product, I have been unable to learn, but it is asserted, and by men whose word is worthy of credence, that almond shells ground into a fine golden colored flour, is much used in this country for adulterating red pepper, cinnamon and other spices.

Almonds are not only used extensively at all times and seasons, by persons of all ages and sexes, at table and elsewhere, but they are employed largely in the making of fancy confectionery with sugar, or in the form of salted almonds, the kernels having been first thoroughly steamed or scalded, to remove the skin, and then rolled or dusted with fine salt. Prepared in this way they are usually considered more readily digestible and healthful than in their natural state.

Sweet almonds are also valued in the form of emulsions, as a medicine in pulmonary disorders, and the oil of almonds is a common standard article in the stock of druggists everywhere, as it enters into the composition of cosmetics, syrups, pastes and powders of various kinds.

The kernels of the wild bitter almond contain a poisonous principle known as hydrocyanic or Prussic acid, which does not exist in the sweet varieties, although found in their leaves and the bark of their twigs. But as bitter almonds are not palatable, there is little danger of anyone being poisoned from eating them, should these nuts ever be cultivated here for any special purpose, as in other countries.

Insects and Diseases.—Whenever the almond tree becomes common here in orchards it will doubtless suffer from the attacks of the same kinds of natural enemies as affect the peach. One of the most widely distributed of these pests is the common peach-tree borer. The parents of these borers are small, slender-bodied, bluish, transparent-winged moths, the male somewhat smaller than the female. These moths usually appear in this latitude during the month of June, and the female deposits her eggs on the stems of the trees near the surface of the ground, or a little below it if she can find a convenient opening to suit her purpose. The eggs deposited soon hatch, and the young larvæ bore through the tender bark at this point, and when fairly under it, branch off, cutting galleries through the soft alburnum underneath. When a number of these borers are at work on the same tree they sometimes girdle and kill it the first season, especially if it is young or a small specimen. But if the tree is not killed outright it will show, by the check to its growth, that borers are at work. The borers continue feeding throughout the remainder of the season, and up to the time freezing weather sets in for the winter, and if not full grown at this time they will finish their growth early in spring, then crawl to near the outside, or just under the old bark, and there spin a thin cocoon, in which they are transformed to the pupal stage, remaining in this form for a few weeks, then issuing in the winged or moth stage.

In the line of preventives and remedies there is nothing better than clean cultivation about the trees, and annual examination of each tree early in summer and the crushing of every borer found. The next best thing, in the way of a preventive, is to wrap the stems from a little below the surface of the ground to a foot or more above it with heavy paper, cloth, or bark of some kind, to keep the moth from laying her eggs on the bark of the tree. I have used common tar paper for this purpose, not only because it is very cheap and does not decay when exposed to the weather, but the exhalation or odor of tar seems to be offensive to the moths. In the use of this material I have never found that it was in the least injurious to the bark underneath. Painting the stems with soap, cement, clay, or even common mineral paints, will answer very well if a little care is given to keeping down the number of insects by removing the larger part of the borers with knife or gouge.

In recent years a pest known as the "shot-hole borer" (Scolytus rugulosus) has appeared in many and widely separated localities, in both the Eastern and Western States, attacking the almond, peach and plum tree. It is supposed to have been introduced from Europe with imported nursery stock, and thence rapidly distributed, by similar means, through the country. In its perfect stages it is a minute brown beetle, about one-twelfth of an inch long and one-thirtieth of an inch in diameter. This pest appears about midsummer, boring numerous minute holes through the bark and into the sapwood underneath, and in this the female deposits her eggs, and from these are hatched the little grubs found later feeding on the soft inner bark and alburnous matter beneath it. From every hole made in the bark a small globule of gum will soon appear, drying upon the surface—thence onward until autumn—and glistening in the sun, an immutable sign of the presence of a minute but destructive enemy.

When the beetles and their eggs are once in possession there is no practical way known of removing them, and the best thing to be done is to cut down and burn every infested tree, and just as soon as it is known to be in this condition. There are also several indigenous species of bark beetles, which will very likely attack almond trees as soon as they are as abundant as peach trees, but all may be destroyed with the same, or very similar weapons and materials.

What are called preventives consist mainly of substances to be applied to the stems in a semi-liquid form, and of such a nature as to be offensive to the beetles because of their odor, taste, or because so hard that the insects cannot cut through them with their mandibles. Common lime whitewash, soft soap, whale-oil soap, or a thin mineral paint made of pure linseed oil, will answer very well for this purpose if applied often enough to keep the bark constantly coated.

Of the fungous diseases affecting the almond in this country, very little is as yet known, although we may safely include under this head all those that have been inimical to the peach, for the transition from this tree to the almond would only be a natural sequence. The peach-leaf curl (Taphrina deformans) would not be far from home on the almond leaf, neither could we expect that almond orchards would be wholly exempt from that mysteriously distributed and uncontrollable disease known as "peach yellows."

In California an almond-leaf blight has already appeared and seriously affected the trees in some of the orchards. It is caused by a fungus known as Cercospora circumscissa Sacc. This fungus attacks the leaves and young twigs, causing the former to fall off early in the season, thereby checking the growth of the tree and preventing the maturing of the fruit. It is thought that remedies may be applied to check this disease, and there will probably be some form of copper solution employed for destroying it, as with various species of fungi on other kinds of fruit trees.