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for trees to be grown in the South. Resistant timber trees, as well as nut trees, could doubtless be produced. Many experiments along this line are already in progress. In the long run the results of breeding will probably be the most profitable outcome of the struggle against the bark disease. Sooner or later we must begin to breed forest trees systematically, and the chestnut is on many accounts a good tree to start with.
INSPECTION OF DISEASED NURSERY STOCK.
As has been indicated, diseased chestnut nursery stock in the past has been an important factor in the spread of the bark disease. On account of a well-grounded fear of this disease much less chestnut nursery stock is being moved now than formerly, but there is still enough to constitute a serious source of danger. It is therefore obvious that every State in which the chestnut grows, either naturally or under cultivation, should as speedily as possible pass a law putting the chestnut bark disease on the same footing as other pernicious diseases and insect pests, such as peach yellows and the San Jose scale, against which quarantine measures are now taken. Many inspectors already have the legal power to quarantine against the bark disease on chestnut nursery stock, and they should now take special care that no shipment, however small, escapes their rigid inspection.
The most serious practical difficulty in inspecting nursery stock for this, as for other fungous diseases, lies in the fact that practically all State inspectors are necessarily entomologists and are usually not trained in recognizing the more obscure symptoms of fungous diseases. Nursery trees affected by the bark disease rarely show it prominently at the time when they are shipped; the threads of conidia or the yellow or orange pustules are rarely present, and usually all the inspector can find is a small, slightly depressed, dark-colored area of dead bark, usually near the ground, which is easily overlooked or mistaken for some insignificant injury. Upon cutting into such a spot the inner bark shows a most characteristic disorganized "punky" appearance quite different from that of any other bark injury. Occasionally a yellowish brown or reddish band or blotch, either girdling or partly girdling the young tree, may be seen, which is very characteristic.
If infected trees are set out they develop the disease with its characteristic symptoms the following spring. On account of their small size such trees are girdled and die before the end of the summer. Meanwhile they become a source of danger to neighboring orchard and forest trees. Orchardists and nurserymen purchasing chestnut trees are therefore warned to watch them closely during the first season, no matter how rigidly they may have been inspected.
INDIVIDUAL TREATMENT OF DISEASED TREES.
Where valuable ornamental, shade, or orchard chestnut trees become infected in one or more spots their life and usefulness can be prolonged for several or for many years, depending largely upon the thoroughness with which the recommendations herein given for cutting out the cankers are carried out. Better results will be obtained with small, thin-barked trees than with large ones.
The essentials for the work are a gouge, a mallet, a pruning knife, a pot of coal tar or good paint, and a paint brush. In the case of a tall tree a ladder or rope, or both, may be necessary, but tree climbers should not be used, as they cause wounds which are very favorable places for infection. Sometimes an ax, a saw, and a long-handled tree pruner are convenient auxiliary instruments, though practically all the cutting recommended can be done with a gouge having a cutting edge of 1 or 1 inches. All cutting instruments should be kept very sharp, so that a clean and smooth cut may be made.
By cutting with the gouge into a diseased area a characteristically discolored and mottled middle and inner bark is revealed. All of this diseased bark should be carefully cut out for an inch or more beyond the discolored area, if the size of the branch will allow it. This bark should be collected in a bag or basket and burned. If the cutting is likely to result in the removal of the bark for much more than half the circumference of the branch or trunk it will probably be better to cut off the entire limb or to cut down the tree, as the case may be, unless there is some special reason for attempting to save the limb or tree. The fungus usually, though not always, develops most vigorously in the inner bark next to the wood. When the disease has reached the wood not only all the diseased bark and an inch of healthy bark around it must be removed, but three or more annual layers of wood beneath the diseased bark must also be gouged out. Special care should be taken to avoid loosening the healthy bark at the edges of the cut-out areas. Except in the early spring, this is not difficult after a little experience in manipulating the gouge and mallet, provided the gouge is kept sharp. Small branches which have become infected should be cut off, the cut being made well back of the diseased spot.
All cut-out areas and all the cut ends of stubs should be carefully and thoroughly painted with coal tar. A good grade of paint has been recommended by some authorities as superior to tar, but it is more expensive. If the tar is very thick the addition of a little creosote will improve it for antiseptic purposes as well as for ease in applying. If the first coat is thin a second one of fairly thick tar should be applied within a few weeks or months. Other coats should be applied later whenever it becomes necessary.
The entire tree should be carefully examined for diseased spots and every one thoroughly cut out and treated in the way described. In case suspicious-looking spots appear, a portion of the outer bark can be cut out with the sharp gouge as a test. If this cut shows the characteristically discolored bark, the spot is diseased and should be cut out accordingly; if the cut shows healthy bark, it need merely be treated with tar or paint, as other cuts are treated. In examining a tree for diseased spots it is always best to begin at the base of the trunk and work up, for if the trunk is girdled at the base it is useless to work anywhere on the tree.
A tree which is being treated for individual infections must be carefully watched and the diseased spots promptly cut out as they appear. For this purpose each tree should be examined very carefully two or three times at least during the growing season. If all the mycelium in the bark and wood has not been removed reinfection is certain to follow.
ADVICE TO CHESTNUT ORCHARDISTS.
In view of the uncertain future of the chestnut tree the United States Department of Agriculture advises against planting chestnuts anywhere east of Indiana, at least for the present.
West of the natural range of the American chestnut, however, the situation is quite different. Obviously the western chestnut orchardist has before him a great opportunity. No matter how successful efforts to limit the bark disease may be, the nut crop will be reduced for some years, and the business of growing fine orchard chestnuts in the East will be depressed for the same length of time. There is no apparent reason why, with rigid inspection of purchased stock and of the orchards themselves, all chestnut orchards and nurseries from Indiana to the Pacific coast can not be kept permanently free from the bark disease; therefore, all persons interested in growing the chestnut in the West are earnestly advised to be sure that stock from any source is rigidly inspected, to watch continually and with the utmost care their own nurseries and orchards, and to destroy immediately by fire any trees that may be found diseased.
ADVICE TO OWNERS OF ORNAMENTAL CHESTNUT TREES.
Until the future of the chestnut tree is better known, the owners of chestnut-timbered land available for building should pursue a very conservative policy. Houses should not be located with sole reference to chestnut groves or to isolated ornamental chestnut trees. Buyers of real estate should discriminate against houses so located in so far as the death of the chestnut trees would injure the appearance of the place.
When ornamental trees become diseased they had better be cut down at once and, if practicable, large trees of other species moved in to take their places. In expert hands the moving of large trees is a perfectly practicable and successful procedure and, although more expensive, is much more satisfactory than waiting for nursery trees to grow.
ADVICE TO OWNERS OF CHESTNUT WOODLAND.
Owners of chestnut woodland that is thoroughly infected are advised to convert their trees into lumber as soon as possible. The trees which are not already killed will soon die in any case, and the timber rapidly deteriorates in quality. Such trees are a continual source of infection.
Owners of chestnut woodland outside the area of general infection are counseled to watch for the first appearance of the disease and when it appears to cut down immediately all affected trees, bark them, and burn the bark and brush, over the stump if practicable. Such procedure will distinctly retard the spread of the disease in that particular woodland, even if no concerted efforts at elimination are made by neighboring owners or by the State.
It is almost needless to add that with the present outlook chestnut woodland is a poor investment. Furthermore, in forest management, as in improvement cuttings, etc., there should be discrimination against the chestnut.
Disease is expected in cultivated plants, grown as they are under unnatural conditions and usually in a strange environment; but a fungous disease as serious as this, attacking a hardy native tree over hundreds of square miles in the heart of its natural range, is, so far as known, without precedent. It is, then, idle to attempt to prophesy what will be the future course of the disease. But whatever the outcome is, we may be sure that the results of the study of this disease will in the end justify all present efforts. We may be certain that this is not the last devastating disease of forest trees to appear, and in the future we shall need all the knowledge and experience that can be gained from this malady. With the increase in the value of timber and with the rapid development of intensive forestry, methods now impracticable for controlling tree diseases will come into regular use, and the practicable methods of the future can only be developed by years of scientific research and field experience on a large scale.
Professor of Meteorological Physics, United States Weather Bureau.
It can be argued, of course, and apparently with good reason, that weather proverbs can not now have any practical use, since nearly every country has a national weather service whose forecasts, for any given time and place, are reliably based upon the known immediately previous conditions all over a continent-conditions that are followed from hour to hour and day to day; that are minutely recorded and carefully studied.
It is true that when one is supplied with such information his horizon becomes world-wide; that he sees the weather as it is everywhere; knows in what directions the storms are moving and how fast, and that therefore he can predict the approximate weather conditions for a day or more ahead. But in general it is not practicable officially to forecast for definite hours nor for particular farms and villages. In the making, then, of hour-to-hour and villageto-village forecasts, though often of great value, one must rely upon his own interpretation of the signs before him. Besides, in many places it is impossible to get, in time for use, either the official forecast or the weather map upon which to base one's own opinions, and under these conditions certain weather signs are of especial value-signs which everyone uses to a greater or less extent but with an understanding of their significance that, according to such experience as only real necessity can give, varies from the well-nigh full and complete to the vague and evanescent.
Thus the fisherman to-day, as in the past, will weigh anchor and flee from the gathering storm when to the uninitiated there is no indication of anything other than continued fair weather; and the woodsman, as did his remotest ancestors, will note significant changes and understand their warning messages when the average man would see no change at all, or if he did, would fail to comprehend its meaning.