The peaches of New York

by U. P. Hedrick

PEACH-YELLOWS

Yellows is a disease or malignant condition, it is not known which, virulent and contagious whatever it may be, and is the possession primarily of the region north of the Ohio and Potomac and east of the Mississippi. At one time or another it has been a cause of decline of the peach-orchards in every part of the region outlined. Epidemics of yellows have wholly obliterated thriving peach-industries which in some cases covered counties. The changes wrought by yellows come so quickly and are so final, so complete and so widespread in their consequences that the disease stands alone among the troubles of plants in the extent of its influence on the crop affected. Under somewhat better control now, its havoc is less than formerly, but in the past it has outdone all other accidents combined that have happened to peaches in America, including frosts, floods, drought, insects, fungi and injuries due to man and quadrupeds. The mystery of yellows in most of its aspects makes its known history all the more significant. We lack knowledge of what it is, or whence it came, nor do we know of any cure; we know only some of the circumstances and the terrible consequences to the peach. Yellows began its siege of the peach in the very beginning of commercial peach-growing in America. Much of the history of the peach is written in the hundred-years-warfare that has ensued.

Judge Richard Peters of Philadelphia first described and gave name to peach-yellows. February 11, 1806, he read a paper "On Peach Trees" before the Philadelphia Society for Promoting Agriculture. In this paper we have the first clear account of yellows:[212]

"About fifty years ago, on the farm on which I now reside, my father had a large peach orchard, which yielded abundantly. Until a general catastrophe befell it plentiful crops had been for many years produced with very little attention. The trees began nearly at once to sicken, and finally perished. Whether by the wasp then undiscovered, or by some change in our climate, I know not. For forty years past I have observed the peach trees in my neighborhood to be short-lived. Farther south, in the western country, and, it seems, in some parts of New Jersey they are durable and productive as they had been formerly here. * * * The worm or grub, produced by the wasp depositing its progeny in the soft bark near the surface of the ground, is the most common destroyer. * * * When trees become sickly I grub them up. I find that sickly trees often infect those in vigor near them by some morbid effluvia. Although I have had trees twenty years old, and knew some of double that age (owing probably to the induration of the bark rendering it impervious to the wasp, and the strength acquired when they had survived early misfortunes), yet in general they do not live in tolerable health after bearing four or five crops. * * * Fifteen or sixteen years ago I lost one hundred and fifty peach trees in full bearing in the course of two summers by a disease engendered in the first season. I attribute its origin to some morbid infection in the air. * * * The disorder being generally prevalent would, among animals, have been called an epidemic. From perfect verdure the leaves turned yellow in a few days, and the bodies blackened in spots. Those distant from the point of infection gradually caught the disease. I procured young trees from a distance in high health and planted them among the least diseased. In a few weeks they became sickly, and never recovered. * * * After my general defeat and most complete overthrow, in which the worm had no agency, I recruited my peaches from distant nurseries, not venturing to take any out of those in my vicinity. I have since experienced a few instances of this malady, and have promptly, on the first symptoms appearing, removed the subjects of it, deeming their cases desperate in themselves and tending to the otherwise inevitable destruction of others."

In the last few lines of this account, Judge Peters gives the only means so far discovered to check the spread of the disease—the prompt destruction of affected trees—a striking commentary on the baffling nature of yellows when we consider what science has done, since Judge Peters wrote, toward the control of other plant-diseases. In a note of later date, page 23 of the same article, Judge Peters speaks of "the disease I call the yellows," thus giving name to a trouble that until then had been known as "decay" or "degeneracy" in the peach.

Later Judge Peters writes:[213] "I am pursuing my old plan of re-instating my peach trees lost last season (1806 or 1807) by my unconquerable foe, the disease I call the yellows. I obtain them from different nurseries free from this pestiferous affection. The worm or wasp (Ægeria) I have in complete subjection. I should be perfectly disinterested in proposing that the society offer a premium for preventing the disease so fatal; for I shall never gain the reward."

And again:[214] "I still think that the disease so generally fatal (more so this year than any other in my memory), called the yellows, is atmospherical. * * * Compare this account (of thrifty orchards in Delaware) with the actual state of the peach in our country, and judge whether we live in a region favorable to its growth. Mr. Heston's attempt at cultivating this tree in the Southern manner begins already to fail. His trees are evidently infected, and many are on the decline. The yellows are universally prevalent this season throughout the whole country (i. e., around Philadelphia)."

We have given but little out of much that Judge Peters wrote on yellows, his observations and experiences covering nearly a generation. We have quoted sufficiently from his accounts, however, indubitably to establish the fact that peach-yellows was rampant about Philadelphia at least as early as 1800. Smith[215] puts the appearance of yellows in this region as probably some time prior to 1791. By this time there was a considerable body of scientific and practical agricultural literature in America, and we may assume, since no trouble that could possibly be identified as yellows had been described as existing elsewhere in America, though the peach-borer is frequently discussed, that the disease at this period, about 1800, was restricted to the neighborhood of Philadelphia.

We now find the yellows gradually extending into neighboring states—Delaware, New Jersey, Maryland and New York. Wm. Coxe of New Jersey who in 1807 wrote Judge Peters, "I am perfectly ignorant of the disease to which you give the name yellows," in 1817 knew it only too well as "a malady which no remedy can cure nor cultivation avert," and devotes nearly two pages in his Fruit Trees to a discussion of its nature.[216] References to yellows in all of the states named by this time had become general. Our purpose to show the spread, effects, and early treatment of the disease is fully served by quoting at length from a single author—a keen observer, careful writer and the most notable horticultural and botanical authority of his time, Wm. Prince, of Flushing, Long Island.[217] To Prince, by the way, we are indebted for the first reference to what is now considered the most certain symptom of yellows—premature ripening of fruit. Prince says:

"This disease, which commenced its ravages in New Jersey and Pennsylvania about the year 1797, and in New York in 1801, and has spread through several of the states, is by far more destructive to peach trees than the worm, and is evidently contagious. This disease is spread at the time when the trees are in bloom, and is disseminated by the pollen or farina blowing from the flowers of diseased trees, and impregnating the flowers of those which are healthy, and which is quickly circulated by the sap through the branches, foliage, and fruit, causing the fruit, wherever the infection extends, to ripen prematurely. That this disease is entirely distinct from the worm, is sufficiently proved by the circumstance, that peach trees which have been inoculated on plum or almond stocks, though less affected by the worm, are equally subject to the yellows—and a decisive proof of its being contagious is, that a healthy tree, inoculated from a branch of a diseased one, instead of restoring the graft to vigour and health, immediately becomes itself infected with the disease. As all efforts totally to subdue it must require a long course of time, the best method to pursue towards its eventual eradication, is to stop its progress, and prevent its farther extension—to accomplish which, the following means are recommended, which have been found particularly successful.