American Pomology. Apples

by J. A. Warder

"This plan has yet been only imperfectly tried. Age and infirmities will probably prevent its completion by me. I will therefore report that I have tested it on a number of my partially blighted pear trees, while a greater numbers has been left to die unmedicated. Of the former, not one has yet perished, while of the latter very few survive. It has appeared, in every instance, to arrest the progress of the disease, and to impart a healthy condition to the bark wherever applied. The apparent results may have been coincidences and not the effect of the remedy. There is much false experience in horticulture and agriculture, as well as in medicine.

"These views suggest the expediency of extensively applying a solution of the sulphate of iron by means of a green-house syringe or garden engine to the tops and foliage of trees, laboring under any of the diseases suspected of a cryptogamous origin. It also becomes a query whether the same agent may not be successfully employed at some period to counteract the potato disease, either by watering with it the growing plant, or washing the tubers in it in autumn, after they are dug. No injury has ever arisen to pear trees by a free use of a saturated solution of copperas.

"In conclusion, I would observe that the discovery of the cryptogamous origin of the many disorders of the human system is effecting important changes in their treatment. May we not hope that an extension of these discoveries to the vegetable kingdom, may result as favorably in shaping the practice in diseases of fruits and fruit trees?"

4th—Wounds, and the attacks of insects, may be considered more in the light of mechanical injuries by a loss of substance, hence they belong rather to the department of surgery, and can scarcely be considered as disease. The breaking of a branch, or the removal of a portion of the bark, may inflict a serious injury, but it is one which, under ordinary circumstances, will be recovered from, without any impairment of the health of the tree—unless where the wound is so large that the new growth will not soon cover it over, in which case exposure to the moisture of the atmosphere may result in decay of the woody tissues, or, if the sap exudes, at certain seasons, it may produce canker and fungous growths. In some varieties of our cultivated fruits, wounds of this character are often attended by an effusion of gummy matter; this is particularly the case with those that are known as stone-fruits, and in these the excision of a large limb is seldom followed by a deposit of woody matter in the way of healing over the wound, which is always desirable; hence in such cases particularly, it is well to cover the exposed surface with something to exclude atmospheric moisture, whether this be paint, varnish, of shellac, or common grafting wax.

Insects, by eating the foliage extensively, very materially injure the healthy condition of a tree—even the minute aphides that suck the sap from the leaves and tender bark, will seriously impair the health of our plants; but the borers that mine under the bark, extensively consuming the vital cambium, and even burrow into the solid wood, reducing it to a honeycomb, cannot fail to affect the healthy condition of the tree materially, and often cause its premature death. Some knowledge of the habits of these little creatures is considered of so great importance, that the subject will be brought before the reader's notice more at length in another part of this volume.

There is no doubt, however, that many unhealthy conditions of our trees, that might be traced to other causes, but which are not manifestly dependent upon a want of care on the part of the orchardist, nor upon a deficiency in the constitution of the soil, are often attributable to the inroads of these minute foes, which, in some cases at least, are made the scape-goats upon which is laid the blame that should be applied to our own neglect, or want of forethought and care.

After having reviewed the whole subject, it may be safe for us to conclude that what is called disease in our cultivated vegetables of whatever kind, is a departure from full health and productiveness of sound fruits. And further that this may arise from a lack of the necessary ingredients in the soil, from a want of proper conditions as to its quality and constitution, particularly with regard to the important elements of moisture, heat, and light; and especially, that this condition of unhealthiness and unproductiveness, when not an inherent failing of the variety, may in many instances be attributable to want of proper care on our part, and to our allowing the trees to injure themselves by overbearing, while we neglect to keep up the proper supply of nourishment.

In making selections of trees for planting, it is important that all weak or unhealthy varieties should be avoided. Secure healthy and vigorous stocks, that appear to be possessed of a sound constitution, even though the fruit should not be quite so fine and beautiful as that produced by some of the sickly and less vigorous varieties. There is more difference apparent, in this respect, among pears than among apples; but of the latter there are varieties that should be avoided on account of their deficient vigor. There are others that might be considered as coming under the ban, because the trees are not long-lived; and yet some of these appear to be perfectly healthy in every other respect, and seem literally to wear themselves out by excessive bearing, producing annual crops of large and handsome fruit, until, utterly exhausted, they reach a premature end.

Some varieties, that for many years yielded very fine crops of the most beautiful fruit, and of the highest character for flavor, have afterward ceased to furnish any perfect specimens—the whole crop being covered and deformed with the black scab or fungus, that prevents their development, or else ruined by the disagreeable bitter-rot which entirely spoils them for any use. Various remedies have been suggested for these maladies, all of which are more or less unsatisfactory, because from our ignorance of the causes of the troubles; these applications are wholly empirical.

The Black-knot, which has become very common in some parts of the country, is well discussed by Benjamin D. Walsh, in the Practical Entomologist, for March, 1866, page 48.