This section is from the book "The Gardener's Monthly And Horticulturist V22", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
A Michigan friend says: " You will see by the proceedings of the Washtenaw County Pomological Society, that your views on the Yellows are somewhat misunderstood as I think. I send you the Michigan Farmer of the 9th inst., containing their proceedings. If you could find time to write out what you think on the subject, or what you have found out, it would be doing our fruit interest some service and put an end to much useless talk, a sort of epidemic from which editors suffer a great deal".
[It seems scarcely possible that regular readers of the Gardener's Monthly can misunderstand the editor's views of the disease known as "yellows" in the peach,and it is useless to follow up the misconceptions of those who only get their notions of his views at second-hand. If anything more for our readers be necessary, we might say that if any one examines a peach-tree in the early stages of the yellows, he will find, by the aid of a microscope, a cobwebby fungus on the roots, which feeds on and destroys the ends of the growing rootlets. He may take if he chooses a shovelfull of this fungus-saturated soil, and place it to the roots of healthy peach-trees, and the following year these trees will be diseased. There can be no doubt from these experiments that this fungus, whatever it be, is the cause of the disease. What the name and history of the fungus is, has never been definitely ascertained. Prof. Farlow has had the mycelium in earth, watching its development, but has not so far been able to determine its exact character. We are inclined to believe it is an Agaric, but our only reason for this belief is that a small brown mushroom usually appears in certain seasons under the trees infested at the roots with the fungus.
This, of course, is but a probability, and will not satisfy exact science. Further, just how the fungus works through the system is not positively ascertained. Prof. Thomas Taylor, formerly of the Department of Agriculture at Washington, has found what he believes to be a minute fungus, working through the structure in connection with the yellows; but whether this has any connection with the root-fungus before noted is not clear. Then there is evidence which we think undoubted, that a peach-stone from a diseased tree, dead leaves from a diseased tree, the use of a knife which has been at work on a diseased tree, as well as the shovelfull of earth we have already referred to, from the roots of a fungus-infested tree, will spread the disease: and all this is in exact accord with what we know of minute fungoid life, and of nothing else. Therefore, while we absolutely know from actual experiment, that the root-fungus produces the yellows, whatever its name and history may be, all the facts connected with the development of the disease show the probable connection with the original root attack.
All that we see against this in the discussion referred to, and others that have occurred in Michigan lately, is that this " theory" is " perfect nonsense," and one gentleman reports that he " examined the roots of a peach-tree with the yellows, but he could not find any fungus." No details are given. He may have had an idea of finding a " fungus" as big as a puff-ball for anything we know. It seems to us that such " opin-ions" are not worth spoiling the paper they ar printed on, and it is no wonder our correspondent suggests that editors suffer a good deal in decd ing what to do with them. - Ed. G. M].
J. K. says: "In all my experience in England as a gardener, I never saw anything like the disease called yellows here. I do not think the thing is found there, and can you tell the reason why?" [It is not easy to tell why, though there may be guesses why, offered. For instance, it is known that the peculiar conditions which call the various species of fungus into existence require to be very nice, and the English climate may be unfavorable to this species; or it may be that the species of fungus which causes the yellows has not been introduced there and would grow well if it were. Most of the Peaches grown in England are grafted on the Plum stock, and the Plum root does not seem to be as choice a morsel for the fungus as the Peach root. It may be that it attacks the Plum sometimes, - but so far we have never known of a case, though it does attack other trees besides Peaches; at least the fungus appears to be the same. - Ed. G. M].
F., Trenton, N. J, writes: "In a recent number of the Rural New Yorker, a correspondent expresses an opinien that pollen from a diseased Peach tree used in fertilizing the flower of a healthy tree, would communicate the disease to the fruit, and in this way a healthy tree might produce seedlings which would have the yellows. As you have given some thought to this matter of Peach yellows, what do you think of this theory? [That the correspondent of the Rural New Yorker is undoubtedly correct. - Ed. G. M].