Εικόνες σελίδας
PDF
Ηλεκτρ. έκδοση

be proposed or discovered. Mr. P. recommends, 1st. Turning up the ground carefully in October, as far as the branches of a tree extend, to half a spade's depth or five inches, so as completely to invert the surface. A great number of chrysalids would thus be exposed to the air and sun, and of course be destroyed. 2dly. Breaking the clods and smoothing the surface with a rake, and passing a heavy roller over it, so as to make it very hard, and without cracks. By these two operations every vestige of their downward path would be completely obliterated, and if any remained undisturbed below the stratum of earth which has been turned up, they must remain there, as it is utterly impossible for them to force their way in the moth or miller state, through such an obstruction as this layer of earth would oppose to them. In grounds the sods should be turned with the grass side down, and placed side by side, so as to be rolled; the earth from which they were taken should be loosed and rolled also. It is probable, that with this treatment no moths would rise in the fall. The winter's frosts would heave and crack the smooth surface, but it might be smoothed and hardened by the roller or other means, in March, with much less trouble, time, and expense, than the long course of tarring requires. As lime, when slacked, is reduced to an impalpable powder, and is thus well adapted to close the least openings in the surface to which it may be washed by rains, Mr. P. is inclined to think its good effects are produced in this way as well as by its caustick quality."

grass

Mr. Kenrick's method of destroying the Canker Worm.

John Kenrick, esquire, of Newton, proposes as follows: From any time in June, after the worms have entirely disappeared, until the 20th of October, let the whole of the soil surrounding the trees,

to the extent at least of four feet from the trunk, and to a suitable depth, be dug up and carted away to a distance from any trees the canker worms are in the habit of feeding upon; and let there be returned an equal quantity of compost, or rich earth intermixed with manure. The earth taken from the trees, will make a substantial ingredient in compost. If a few straggling canker worms appear on any of the trees the spring following, let such trees be marked, that the operation may be repeated the succeeding summer. The process proposed will not only accelerate the growth, and increase the fruitfulness of the trees, but will prove a considerable guard to them against the depredations. of moles in the winter following; advantages which will abundantly outweigh the whole expense. But the pre-eminent advantage obtained, will be to have captured those destructive invaders, broken up and completely destroyed their encampments. Annual tarring, the only remedy in general use, instead of being beneficial to the trees, is allowed on all hands to be injurious. The seasons being variable, it requires considerable care and skill to know when to begin; if one day too late, some of the canker moths will have ascended the trees; if four days too early, so much labour and tar are lost. The same difficulty occurs in knowing when to cease tarring. The business must be attended to exactly in the right time, whether it rain or shine, and the operation repeated considerably more than twenty times in every season; and the average of various estimates of the annual expense of tarring each tree amounts to full ten cents. The method I have proposed, says Mr. K., appears to be perfectly adapted to the convenience of the practical farmer. He will avoid the trouble and expense of purchasing and applying tar, lime, or any other article; he can perform the operation when most at leisure, and

with a certain prospect of ample reward for his labour, even if no damage were apprehended from the canker worm; and if the operation is performed in June, he can raise a crop of potatoes round the trees the first season. Hence it is obvious, that several very important advantages will be obtained in addition to the prime object; and the prudent farmer, who adopts this method, will have in view the most, if not the whole, of the following distinct objects:

1. Extermination of the canker worms.
2. Growth of the trees.

3. Fruitfulness of the trees.
4. Defence against the moles.
5. Several crops of potatoes.
6. Manufacture of compost.

Mr. Kenrick never having had any canker worms on his farm, could not personally prove the efficacy of the method proposed, by actual experiment. But it should be strongly recommended to the attention of cultivators of orchards, and it is hoped the publick may be made acquainted with the result of every trial.

[ocr errors]

John Lowell, esquire, (Mass. Agricul. Repos.) observes, that "the expense of tarring an orchard for several years, together with the injury sustained by the trees in the common mode of doing it, will be nearly equivalent to a total loss. The improvements, introduced by Mr. Parsons, and other cultivators, of surrounding the trees with canvass and rope-yarn, and stopping the descent of the tar by a bandage of coarse hemp, together with the mixture of the tar with oil, so as to keep it longer in a soft state, have very much diminished the inconvenience of the old practice. Still much remains to be desired. The process is imperfect, unless performed as faithfully in the fall as in the spring. If your neighbours are inattentive, you may be subjected to this labour for ten or twenty

your

the con

years, and orchards will scarcely pay tinued and accumulated expense. Something further seems to be desirable; some mode more simple, less expensive, more effectual. In the southern states, I perceive, some persons are still ignorant of the natural history of this insect, and regret that it has not been examined and described by scientifick men. We have nothing left to be desired on this head. The description of the canker worm, by professor Peck, is very satisfactory, and only leaves us to regret that the same ingenuity could not have devised some speedy, simple mode of extirpating or checking them. Until some effectual mode is discovered, I think we should make constant experiments, and communicate fully the results, in the hope that if our trials shall not prove in every case successful, they may stimulate others to more happy ones.

"I had understood that Mr. Josiah Knapp, of Boston, was induced to try the effect of air-slacked lime. He put it round one of his trees in the spring of 1814, and I have been assured, not only by him, but by another respectable friend who examined it, that it was fully successful. The tree was in a small garden in Boston, surrounded with other trees, which were filled with the worms, and this one wholly escaped, except that a few appeared to have attacked its extremities, where they were interlocked with the other trees. I mentioned this fact to a Rhode Island gentleman, who informed me that, in that state, they had used the rubbish collected from the breaking of flax, and it had effectually prevented the rise of the insect. I resolved to make the experiment of lime on an extensive scale. As the insects rise in the fall, I determined to put the lime on in autumn. For this purpose I had the turf dug in around sixty apple trees, and the earth laid smooth. I then took three hogsheads of effete or air-slacked lime, and strewed it an inch thick

round my trees, to the extent of about two or three feet from the roots, so that the whole diameter of the opening was from four to six feet. I tarred these trees as well as the others, and although I had worms or grubs on most that were not limed, I did not catch a single grub where the trees were limed. I do not mean to speak with confidence ; I am, however, strongly encouraged to believe the remedy perfect. It was ascertained by professor Peck, that the insect seldom descended into the ground at a greater distance than three or four feet from the trunk, and to the depth of four inches, or that the greater part come within that distance. The lime is known to be destructive to all animal substances, and I have little doubt that it actually decomposes and destroys the insect in the chrysalis state; at least, I hope this is the case. There are

many reasons which should encourage the repetition of this experiment. The digging round the trees is highly useful to them, while tarring is very injurious. The expense is not great; a man can dig round fifty large trees in one day. The lime is a most salutary manure to the trees. After the

spot has been once opened and limed, the labour of keeping it open will not be great. Three hogsheads of air-slacked lime, or sweepings of a lime store, will suffice for fifty trees, and will cost three dollars. As it is done but once a year, I think it cannot be half so expensive as tarring. I repeat it, sir, that I mention my experiment with great diffidence, as being the first of my own knowledge. It may induce several persons to try it in different places, and where trees are surrounded with others which are treated differently. All I pray is, that it may prove to be successful, and relieve us from this dreadful scourge, which defaces our country, while it impoverishes and disappoints the farmer. If it should succeed, Mr. Knapp will merit the thanks of the publick for his ingenious experiment."

« ΠροηγούμενηΣυνέχεια »