The Yellows is usually regarded as a disease. Imagination has invented many causes of this evil. Some suppose it to be produced by small insects; others that it is in the seed. Again, it is ascribed to the atmosphere. It has been supposed to be propagated in many ways—by trimming a healthy tree with a knife that had been used on a diseased one; by contagion in the atmostphere, as the measles or small-pox; by impregnation from the pollen, through the agency of winds or bees; by the migration of small insects; or by planting diseased seeds, or budding from diseased trees. This great diversity of opinion leaves room to doubt whether the yellows in peach-trees be a disease at all, or only a symptom of general decay. The symptoms, as given in all the fruit-books, are only such as would be natural from decay and death of the tree, from any cause whatever. This may result from neglect to supply the soil with suitable manures, and to trim trees properly, and especially from over-bearing. This view of the case is more probable, from the fact that none pretend to have found a remedy. All advise to remove the tree thus affected at once, root and branch. We have seen the following treatment of such trees tried with marked success. Cut off a large share of the top, as when you would renew an old, neglected tree; lay the large roots bare, making a sort of basin around the body of the tree, and pour in three pailfuls of boiling water: the tree will start anew and do well. This is an excellent application to an old, failing peach-tree. The sure preventive of the yellows is, planting seeds of healthy trees, budding from the most vigorous, heading-in well, supplying appropriate manures, and general good cultivation.
Curled Leaves is another evil among peach-trees, occurring before the leaves are fully grown, and causing them to fall off after two or three weeks. Other leaves will put out, but the fruit is destroyed, and the general health of the tree injured. Elliott says the curl of the leaf is produced by the punctures of small insects. One kind of curled leaf is, but not this. But we have no doubt that Barry's theory is the correct one, viz., that it is the effect of sudden changes of the weather. We have noticed the curled leaf in orchards where the trees were so close together as to guard each other. On the side where the cold wind struck them, we noticed they were badly affected; while on the warm side, and in the centre where they were protected by the others, they exhibited very few signs of the curl. In western New York, unusual cold east winds always produce the curled leaves, on trees much exposed: hence, the only remedy is the best protection you can give, by location, &c.
Mildew is a minute fungus growing on the ends of tender shoots of certain varieties, checking their growth, and producing other bad effects. Syringe the trees with a weak solution of nitre, one ounce in a gallon of water, which will destroy the fungus and invigorate the tree.
The Borer has been the great enemy of the peach-tree, since about the close of the last century. The female insect, that produces the worms, deposites her eggs under rough bark, near the surface of the ground. This is done mostly in July, but occasionally from June to October. The eggs are laid in small punctures, and covered with a greenish glue; in a few days they come out, a small white worm, and eat through the bark where it is tender, just at, or a little below, the surface of the ground; they eat under the bark, between that and the wood, and, consuming a little of each, they frequently girdle the tree; as they grow larger, they perforate the solid wood; when about a year old, they make a cocoon just below the surface of the ground, change into a chrysalis state, and shortly come out a winged insect, to deposite fresh eggs. But the practical part of all this is the remedy: keep the ground clean around the trees, and rub off frequently all the rough bark; place around each tree half a peck of air-slaked lime, and the borer will not attack it. This should be placed there on the first of May, and be spread over the ground on the first of October; refuse tobacco-stems, from the cigar-makers, or any other offensive substance, as hen-manure, salt and ashes, &c., will answer the same purpose. We should recommend the annual cultivation of a small piece of ground in tobacco, for use around peach-trees. We have found it very successful against the borer, and it is an excellent manure; applied two or three times during the season, it proves a perfect remedy, and is in no way injurious, as an excessive quantity of lime might be.
Leaf Insects.—There are several varieties, which cause the leaves to curl and prematurely fall. This kind of curled leaf differs from the one described as the result of sudden changes and cold wind; that appears general wherever the cold wind strikes the tree, while this only affects a few leaves occasionally, and those surrounded by healthy leaves. The remedy is to syringe them with offensive mixtures, as tobacco-juice, or sprinkle them when wet with fine, air-slaked lime.
Varieties.—Their name is legion, and they are rapidly increasing, and their synonyms multiplying. A singular fact, in most of our fruit-books, is a minute description of useless kinds, and such descriptions of those that they call good, as not one in ten thousand cultivators will ever try to master—they are worse than useless, except to an occasional amateur cultivator.
Elliott, in his fruit-book, divides peaches into three classes: the first is for general cultivation; under this class he describes thirty-one varieties, with ninety-eight synonyms. His second class is for amateur cultivators, and includes sixty-nine varieties, with eighty-four synonyms. His third class, which he says are unworthy of further cultivation, describes fifty-four varieties, with seventy-seven synonyms. Cole gives sixty-five varieties, minutely described, and many of them pronounced worthless. In Hooker's Western Fruit-Book, we have some eighty varieties, only a few of which are regarded worthy of cultivation. Downing gives us one hundred and thirty-three varieties, with about four hundred synonyms. In all these works the descriptions are minute. The varieties of serrated leaves, the glandless, and some having globose glands on the leaves, and others with reniform glands. Then we have the color of the fruit in the shade and in the sun, which will, of course, vary with every degree of sun or shade. We submit the opinion that those books would have possessed much more value, had they only described the best mode of cultivating peaches, without having mentioned a single variety, thus leaving each cultivator to select the best he could find. Had they given a plain description of ten, or certainly of not more than fifteen varieties, those books would have been far more valuable for the people. We give a small list, including all we think it best to cultivate. Perhaps confining our selection to half a dozen varieties would be a further improvement:—
1. The first of all peaches is Crawford's Early. This is an early, sure, and great bearer, of the most beautiful, large fruit;—a good-flavored, juicy peach, though not the very richest. It is, on the whole, the very best peach in all parts of the country. Time, from July 15th to September 1st. Freestone.
2. Crawford's Late is very large and handsome; uniformly productive, though not nearly so good a bearer as Crawford's Early. Ripens last of September and in October. Fair quality, and always handsome; freestone; excellent for market.
3. Columbia.—Origin, New Jersey. It is a thoroughly-tested variety, raised and described by Mr. Cox, who wrote one of the earliest and best American fruit-books. Fine specimens were exhibited in 1856, grown in Covington, Ky. Excellent in all parts of the United States. Freestone.