Pleasant Talk About Fruits, Flowers and Farming

by Henry Ward Beecher

1st. That the blight thus produced is limited, and probably sectional or local. No account has met my eye which leads me to suppose that any considerable injury has been done by it. Mr. Manning, of Salem, Mass., in the second edition of his “Book of Flowers,” states that he has never “had any trees affected by it”—the blight. Yet his garden and nursery has existed for twenty years, and contained immense numbers of trees.

2d. It is very plain that neither Mr. Lowell, originally, nor Dr. Harris, nor any who describe the blight as caused by the blight-beetle, had any notion of that disease which passes by the same name in the middle and western States. The blight of the scolytus pyri is a mere girdling of the branches—a mechanical separation of parts; and no mention is made of the most striking facts incident to the great blight—the viscid unctuous sap; the bursting of the bark, through which it issues; and its poisonous effects on the young shoots upon which it drops.

We do not doubt the insect-blight; but we are sure that it is not our blight. We feel very confident, also, that this blight, which from its devastations may be called the great blight, has been felt in New England, in connection with the insect-blight, and confounded with it, and the effects of two different causes happening to appear in conjunction, have been attributed to one, and the least influential cause. The writer in Fessenden’s American Gardener (Mr. Lowell?) says of the blight, “it is sometimes so rapid in its progress, that in a few hours from its first appearance the whole tree will appear to be mortally diseased.” This is not insect-blight; for did the blight-beetle eat so suddenly around the whole trunk? Now here is a striking appearance of the great blight, confounded with the minor blight, as we think will appear in the sequel.

This theory has stood in the way of a discovery of the true cause of the great blight; for every cultivator has gone in search of insects; they have been found in great plenty, and in great variety of species, and their harmless presence accused with all the mischief of the season. A writer in the Farmer’s Advocate, Jamestown, N. C., discerned the fire-blight, and traced it to “small, red, pellucid insects, briskly moving from place to place on the branches.” This is not the scolytus pyri of Prof. Peck and Dr. Harris.

Dr. Mosher, of Cincinnati, in a letter published in the Farmer and Gardener for June, 1844, describes a third

insect—“very minute brown-colored aphides, snugly secreted in the axilla of every leaf on several small branches; … most of them were busily engaged with their proboscis inserted through the tender cuticle of this part of the petiole of the leaf, feasting upon the vital juices of the tree. The leaves being thus deprived of the necessary sap for nourishment and elaboration soon perished, … while all that part of the branch and trunk below, dependent upon the elaborated sap of the deadened leaves above, shrunk, turned black, and dried up,” p. 261.

Lindley, in his work on Horticulture, p. 42-46, has detailed experiments illustrating vegetable perspiration, from which we may form an idea of the amount of fluid which these “very-minute brown-colored aphides” would have to drink. A sunflower, three and a half feet high, perspired in a very warm day thirty ounces—nearly two pounds; on another day, twenty ounces. Taking the old rule, “a pint a pound,” nearly a quart of fluid was exhaled by a sunflower in twelve hours; and the vessels were still inflated with a fresh supply drawn from the roots. Admitting that the leaves of a fruit-tree have a less current of sap than a sunflower or a grape-vine, yet in the months of May and June, the amount of sap to be exhausted by these very minute brown aphides, would be so great, that if they drank it so suddenly as to cause a tree to die in a day, they would surely augment in bulk enough to be discovered without a lens. If some one had accounted for the low water in the Mississippi, in the summer of 1843, by saying that buffaloes had drank up all the upper Missouri, and cut off the supply, we should be at a loss which most to pity, the faith of the narrator, or the probable condition of the buffaloes after their feat of imbibition.

But the most curious results follow these feats of suction. The limbs and trunk below shrink and turn black, for want of that elaborated sap extracted by the aphides. And yet every year we perform artificially this very operation in

ringing or decortication of branches, for the purpose of accelerating maturation or improving the fruit. Every year the saw takes off a third, a half, and sometimes more, of a living tree; and the effect is to produce new shoots, not death. Is an operation which can be safely performed by man, deadly when performed by an insect? Dr. Masher did not detect the insects without extreme search, and then only in colonies, on healthy branches. Do whole trees wither in a day by the mere suction of such insects? Had they been supposed to poison the fluids, the theory would be less exceptionable, since poisons in minute quantities may be very malignant.

While we admit a limited mischief of insects, they can never be the cause of the prevalent blight of the middle and western States—such a blight as prevailed in and around Cincinnati in the summer of 1844—nor of that blight which prevailed in 1832. The blight-beetle, after most careful search and dissection, has not been found, nor any trace or passage of it. Dr. Mosher’s insect may be set aside without further remark.