LETTER OF TRANSMITTAL.

THE COMMISSION FOR THE INVESTIGATION AND CONTROL OF THE CHESTNUT TREE BLIGHT IN PENNSYLVANIA

1112 Morris Building, Broad and Chestnut Streets

Philadelphia, December 9th, 1913.

HON. JOHN K. TENER, Governor, Harrisburg, Penna.

Sir: We have the honor to transmit herewith our report of the operations of this Commission for a portion of the year 1913, this being also the final report of the Commission.

Eastern Asia, the home of the San Jose scale, has been found to be also the home of the chestnut blight. The disease has been found definitely in northeastern China; probably it is also present in Japan. There is no reason to doubt that it found its way to this country in the same way that the San Jose scale did, on nursery stock, and at about the same time, or perhaps somewhat later. Any system of strict inspection of imported nursery stock could have kept it out of this country, but no such system was then in use. It would probably not have been possible at that time to secure a law authorizing such inspection because of the lack of public appreciation of the seriousness of imported fungous and insect epidemics.

The oldest known spots of chestnut blight infection are in the neighborhood of New York City. Here again the disease could have been checked at an early date and never found its way into Pennsylvania, but nothing of the sort was even attempted. In fact, even up to 1911, no official work was done in New York upon the disease. In 1908 Murrill⁠[1] advocated cutting out all chestnut trees within half a mile of diseased trees, but this plan was never put into practice in New York. In general, the greatest conservatism has prevailed regarding the seriousness of the disease. The view that the fungus was native to America, and its great virulence due to winter injury and other temporary climatic effects upon the trees, has been strenuously advocated. The Commission from the first, however, adopted the theory of the Department of Agriculture that the disease was of foreign origin and hence to be considered in the light of a dangerous invader. This view has since been amply justified. Pennsylvania was the first state to treat the epidemic seriously, but by the time the Commission was able to begin work the disease was spread over the eastern half of the State too completely to make its eradication there possible.

Twenty years ago such an epidemic as the present one would have attracted little attention, but now the prices of all classes of timber have been for some years increasing, and promise to continue to increase indefinitely. It is obvious that every possible care must be taken of the present forest stand; upon this point there is no longer disagreement. In Pennsylvania the chestnut is especially valuable, standing in intimate relation to many of the leading industries of the State. It is distributed throughout the State, comprising at least one-fifth, possibly one-third, of the timber. It is naturally adapted to poor, hilly land not suited for agriculture, and will produce profitable yields of extract wood, fence posts, rails, etc., in 25 to 30 years; and ties, poles, and saw timber in 40 to 50 years. Because of its comparatively rapid growth, its superior ability to perpetuate itself by means of sprouts, and the great variety of its uses, the chestnut may be considered the most important forest tree in the State. The ease with which chestnut can be managed according to the principles of forestry made it, before the appearance of the blight, one of the principal species depended upon to solve the problem of the future timber supply of the State. On steep slopes, where the per cent. of chestnut is high, serious deterioration, washing of the soil, and reduction in water supply will undoubtedly follow the destruction of the chestnut trees.

The complete loss of the present commercial stand of chestnut in Pennsylvania, which, now that the Commission has ceased work, seems absolutely certain, is a calamity which will be fully realized only in the future. In matters of this kind we have obligations to the future, aside from the particular emergency in hand. This is not the last tree disease that will sweep over the State. All efforts to control this disease would be justified even if we only learned how to control the next one. Methods which may not be practicable now will be highly practicable twenty years from now on account of the steady increase which is bound to come in timber values. The mere fact that this campaign against the chestnut blight has been undertaken at all shows a great advance of thought over that of previous years.

With these facts in mind, it is obvious that three courses were possible, when the extent and seriousness of the chestnut blight was first realized in Pennsylvania.

First,—Do nothing.

Second,—Conduct scientific investigations of the disease with the hope of determining by laboratory methods and very small field experiments some method of control.

Third,—Conduct scientific investigations, and at the same time immediately attack the epidemic by any and every means that seemed to afford any possibility of checking or even delaying the course of the disease. To follow the first method would have been to emulate simply the example of New York and New Jersey. The second course had many points in its favor, but it was obvious that such a course would yield no results in time to be used on the present epidemic, though possibly of the largest ultimate value. The third course appealed to the Commission as the only one possible under existing circumstances. The greatest handicap was the extent to which the disease was already present in the State.

In the eastern half of the State the disease was obviously beyond control. In the western half the best course available, and in fact the only method that has been proposed at all for control of the disease, was that of cutting out the advance infections. While this method is open to many criticisms, nothing better has been proposed even to the present time. The Commission adopted the cutting out methods advocated by the U. S. Department of Agriculture with two exceptions: (1). Spots of considerable size were cut out in some cases; that is, the cuttings were not limited to strictly advance infections. (2). No immune zone was established at first, although this might have been done later. The method was essentially that advocated by Murrill in 1908, except that trees were not cut to as great a distance as half a mile from the source of infection. Detailed reports of the cutting out work are appended. It is sufficient to say here that the progress of the disease in the western half of the State has been set back five years, and west of the line extending from Bradford to Somerset counties there is little infection, and what infection there is dates from 1913. There is no reasonable doubt that the disease could have been kept instatu quo indefinitely, had the work of cutting out continued. As set forth in the appended reports, the methods of cutting out have been improved, the cost determined and reduced, and winter scouting established as a practical method. These methods developed by the Commission are now in active use in the States of Virginia and West Virginia, where the campaign of eradication is being vigorously pursued.

One of the most valuable results of the Commission’s work was the establishment of the fact that the wood of a blighted tree is entirely fit for use, and if utilized soon after the death of the tree from blight, can be disposed of in the regular way and at normal values. The Commission has advocated the cutting out of all diseased trees, since on account of the prejudice against blighted poles and timber, and the possibility of the market becoming glutted, this is the best plan. Also the cutting of diseased trees was urged because it would reduce the sources of infection. Since utilization was all that remained to be done in the eastern half of the State, the Commission secured a special reduced freight rate on blighted lumber, determined what demand there was in and out of the State for chestnut lumber and other chestnut products, and proceeded to bring owners and dealers together. This work had just reached the point of its highest efficiency when the Commission ceased work. As there is no longer any means of inspection and certification of diseased lumber, the reduced freight rate is no longer available.

When the Commission began work but few investigations had been made of the chestnut blight, and other States, as well as the U. S. Department of Agriculture, were working on the disease without special funds. The Commission by its example and by its direct efforts, assisted in securing Congressional and State appropriations, and practically all of the scientific work and all of the practical work which has been done on this disease since 1910 was made possible by the efforts of this Commission. A National law was passed which requires strict inspection of all imported nursery stock and the prohibition from entry of certain classes of stock, and which makes the repetition of such an event as the importation of the chestnut blight impossible, or at least highly improbable. The work of this Commission was one of the greatest factors in bringing about the passage of this law.

Not only has the work of the Commission aroused public attention throughout the Eastern States regarding this disease, but the public is awakened as never before by the example of the destruction of one species to the necessity of conservation of all timber resources. In this State the Commission has carried on a liberal educational campaign in which it has had the hearty co-operation of the State Forestry Department, the Conservation Association, such organizations as the Boy Scouts, various lumber and trade associations, and many other organizations, institutions, and individuals.

In conclusion, it seems necessary to call sharp attention to the real lesson to be learned from the chestnut blight epidemic—viz.: the necessity of more scientific research upon problems of this character; to be undertaken early enough to be of some value in comprehending, if not controlling the situation. We have seen that the blight might have been kept out of the country in the first place by inspection, or once in, that it might have been destroyed, or at least checked before it had gotten widely distributed. But instead it was permitted to enter, and to spread for many years without scientific notice, and for several more years without any organized attempt to control it, or even to study it seriously. Are we doing any better now with reference to the future?

China has been shown to be the home of the chestnut blight. China, then, would seem to be the obvious place to study it; but no pathologists are there, and state and federal parsimony has so far failed to provide for any investigations of the disease on its home ground by American pathologists.

It has been proposed to replace the chestnut in southern New England by plantings of white pine, in itself the most important eastern timber tree; but the white pine is in turn subject to a newly imported disease, the blister rust. It is not certain that very serious and united efforts are being made to investigate and control this disease even in the States that introduced it. As in the case of the chestnut blight, scepticism has even been expressed as to its seriousness. Again, it would seem that the obvious place to determine the seriousness of the blister rust was in Europe, its home; yet to date neither state nor National government has dispatched a scientist on this errand. In this connection it may not be amiss to call attention to the fact that in Pennsylvania there is, aside from the employees of this Commission, only one professional plant pathologist! Yet the preventable damage which this one plant disease—chestnut blight—has done, would pay for the work of more plant pathologists than are now at work in the entire world.

The Commission closes its work with regret, knowing well that the blight will now spread over the State without hindrance. There is some satisfaction in knowing, however, that the work left undone in Pennsylvania has been actively taken up in Virginia and West Virginia, and that the States of Ohio and North Carolina are making studies preparatory to combatting the disease as soon as it appears in those States. The scientific research carried on by the Commission will be continued by the U. S. Department of Agriculture. We may be certain that the war against this and other foreign epidemics will not cease until science is so far advanced in both theory and practice that they can be controlled.

Very truly yours, WINTHROP SARGENT, Chairman.

Report of

Hon. I. C. Williams

Deputy Commissioner of Forestry, Collaborator

A common mark of the blight. Small leaves which developed in the early spring on a top recently girdled by the blight, showing midsummer condition. Withered leaves above the canker; sprouts below.

A HISTORY OF THE EARLY PENNSYLVANIA EFFORT TO COMBAT THE CHESTNUT BARK DISEASE.

BY HON. I. C. WILLIAMS, DEPUTY COMMISSIONER OF FORESTRY, COLLABORATOR, HARRISBURG, PA.

Preliminary to the final report of the Chestnut Blight Commission, it is thought desirable to make a statement detailing the history of the chestnut bark disease in Pennsylvania so far as known, and of the efforts to combat it, leading up to the formation of the Commission under the law of 1911, and the extended work of repression begun at that time.

The attention of the Pennsylvania Department of Forestry was first attracted to the appearance of the chestnut bark disease in this State by a letter from Mr. Harold Peirce, of Haverford, dated July 18, 1908, reporting its presence in Lower Merion Township, Montgomery County, and by an article appearing in the November, 1908, number of “Conservation,” from the pen of Dr. John Mickleborough, of Brooklyn. Subsequent correspondence with Dr. Mickleborough revealed the fact that he had been a student of the disease for over a year and had become familiar with it in all of its ordinary aspects. To these two gentlemen, therefore, the State is primarily indebted for the subsequent efforts made to study more particularly, and to attempt to control this vicious tree disease.

The facts relating to the discovery of the disease in America and its identification are pretty well known. It was first detected by Dr. Hermann W. Merkel, in the Bronx Zoological Park, New York City, in 1904, although it is almost certain that it existed in that neighborhood for probably more than a year prior to Dr. Merkel’s discovery. Referred for identification to Dr. W. A. Murrill of the New York Botanical Garden, he published a description of it in 1906⁠[2], and by him the fungus was named Diaporthe parasitica, so called because it was believed to be the only parasitic species of the genus. The naming of the fungus has since been corrected by means of the researches of Anderson, Clinton, Farlow, Shear and Stevens, and it is now known systematically as Endothia parasitica.

Some controversy has been had over the origin of the disease and the case is probably not yet settled. Dr. Clinton’s contention is and has been, that it is a native fungus, which, by means of weather conditions and possibly other factors, has taken on new attributes. Dr. Metcalf, his co-worker Prof. Collins, Dr. Shear, and others believed and still maintain that it is of foreign origin, introduced into America by the importation of horticultural stock. Its first known appearance in the region of New York City and its spread in concentric zones from that point as a centre of infection, lent much plausibility to this theory. The recent discovery made by Mr. Frank N. Meyer, of the same fungus in northeastern China, where it is parasitic on Castanea, and where, it appears, the host trees have become rather highly resistant to its attack, leads further probability of correctness to Metcalf’s theory.

Possibly a great hope for America lies in this Chinese discovery. Pathologists and foresters are anxiously looking forward to the results of experiments now being made and which will be attempted, we hope, on a much larger scale in the future. The regrettable, ever-present fact is that this disease is with us here and now, and must be reckoned with from every angle of attack. There seems to be no present diminution sufficient to warrant the belief that it is likely to wear itself out, or that our trees will become sufficiently resistant to ward off the attack prior to the destruction of the trees themselves.

Subsequent correspondence between Dr. Mickleborough and the Department of Forestry culminated in a letter from him under date of March 9, 1909, in which he outlined a definite plan for the examination of a supposedly infected territory in southeastern Pennsylvania, and offered his services to the Commonwealth for carrying out plans of investigation. The proposed inspection was approved by the Department on March 17, 1909, and the services of Dr. Mickleborough thus enlisted. The first inspection visit was made by him in company with the writer, March 29, 1909, at Mt. Holly, in Cumberland county, but where no evidence of the disease was found at that time.

Prior to the beginning of this work in 1909, Dr. Mickleborough had been invited by Dr. Jane Baker, physician in charge of the Chester County Insane Hospital, to speak before an educational conference at Embreeville, Chester county. At this time the disease was not generally prevalent in that region, but a number of infected chestnut trees were found.

The work of inspection over the southeastern portion of the State thus undertaken under the direction of the Department of Forestry, as stated above, was conducted by Dr. Mickleborough, and carried through or into almost every county east of the Susquehanna. During the progress of this examination the chestnut blight was not found north and west of the South Mountain, although prior to this time the United States Department of Agriculture had reported the existence of two spot infections in the western portion of the State, near Altoona, and a re-examination of the material relating thereto by Dr. Metcalf and his assistants, seemed to leave no doubt as to the correctness of this report. Certain it is that in May, 1909, there was no large or extended infection west of the Susquehanna. Had there been in existence at that time the means to carry on work of control along both sides of the Susquehanna River, who can tell what the result might have been, looked at in the light of our present knowledge?

The report of Dr. Mickleborough’s inspection and study was published by the Department in the autumn of 1909. This is a 16 page pamphlet illustrated by drawings showing a portion of the structural formation of the fungus, and by a Lumiere color photograph of a stem section of chestnut covered externally by the fruiting fungus. This specimen of infected chestnut wood was sent in from Pike county, in the upper Delaware valley, and was incubated and developed in a moist cell in the Department of Forestry during the summer of 1909.

In the early part of the study of this bark disease, it was believed that the Japanese species of Castanea was either immune or highly resistant to attack. Several specimens of Japanese chestnut were under observation on Long Island, and fairly gave rise to this belief. One grove examined near Westbury, in June, 1909, showed the Paragons and common chestnuts badly attacked. The Japanese showed no attack at all.

Through the courtesy of the Hicks nursery at Westbury, forty-five young chestnut trees supposed to be Japanese, and one hundred grafting scions were sent to the chestnut orchard of Mr. Levi Wise, at Gap, Lancaster county, Pennsylvania, and distributed among four persons of the neighborhood for planting and testing out for immunity. The bark disease was at that time particularly prevalent in the chestnut woods at this place. Some of the newly planted trees died from other causes, but enough of them were attacked and killed by the blight to show that these particular trees, at least, were not immune.

On the 29th day of March, 1910, Dr. Mickleborough delivered a lecture on the subject of this tree disease before the Main Line Citizens’ Association at the Merion Cricket Club, Haverford, Pa. This meeting was arranged largely through the efforts of Mr. Peirce, who at that time was the owner of several acres of chestnut woodland, and of which tract Dr. Mickleborough made a rather extended examination, finding the chestnut blight present in a number of trees. This discovery and the lecture delivered on the subject brought the matter prominently to the attention of the citizens of that neighborhood, and later led to some very important developments with respect to studying and combating the disease.

Following this address by Dr. Mickleborough, Mr. Peirce was in correspondence with the Department of Forestry, calling attention to the inroads being made upon the chestnut trees by this disease in the neighborhood of his residence, requesting the Department to render such help as it might be able in assisting the people to understand the situation better, and, if possible, to eliminate or at least attempt to control the trouble. This correspondence culminated in the calling of a meeting on May 23, 1910, at the house of Mr. Robert W. Lesley, at Haverford, which was attended by a number of the residents and land owners of the neighborhood, by Dr. John W. Harshberger, the botanist, representing the University of Pennsylvania, and by the Deputy Commissioner, representing the Pennsylvania Department of Forestry.

The preliminary arrangements for beginning an extensive survey of this region were discussed at this meeting. The Department representative made his report to the Forestry Commission at its meeting held on June 3, 1910. On motion of Dr. Rothrock, the Commission directed that the Department render the desired help, and on the same day a letter to this effect was sent to Mr. Peirce, the secretary of the citizens’ meeting. On September 1, 1910, a corps of inspectors from the Department in charge of the Deputy Commissioner, arrived at Haverford and Ardmore, prepared to begin their work. Offices were speedily fitted up in the building of the Merion Title and Trust Company at Ardmore, and the first inspection of trees was made on the property of Mr. Lesley on Saturday, September 3rd. From this date forward until December 19, 1910, the work was vigorously carried on, and a close inspection made of 296 properties, covering most of the region extending from Overbrook to Paoli, and from the Schuylkill River on the north, to a considerable distance south of the Pennsylvania Railroad. A draft of each property was prepared showing the location of all chestnut trees and indicating those which at that time were apparently free of disease, as well as those showing the infection. Each property owner was then furnished with a copy of the report and draft relating to his own land.

To show the interest taken in this work by members of the Main Line Citizens’ Association, it is necessary only to state that the work was carried on almost entirely at the expense of the association. The individual contributions for the purpose amounted to $2,707.70.

During the progress of this inspection, a second public meeting was held in the auditorium of the Merion Cricket Club, at which time a preliminary report was submitted and discussion had with respect to the situation as it then existed. This meeting was attended by a large number of ladies and gentlemen, members of the association, and much interest was shown in the progress reported. The final report of the committee of the association having the work in charge was printed and rendered to the members under date of May 8, 1912. This committee was as follows: Messrs. Harold Peirce, Chairman; Theodore N. Ely, Allan Evans, Edgar C. Felton, William Righter Fisher, Alba B. Johnson, and Robert W. Lesley.

In a letter bearing date the 12th day of March, 1909, addressed to the Commissioner of Forestry at Harrisburg, Dr. Mickleborough used this language. “As to remedy, the best that can be suggested by anyone at present is Control and not Extermination, for various reasons. This I think is also true of the San Jose scale.” It will thus be seen that the original idea involved in the attack on the chestnut blight in Pennsylvania was control, just as the Department of Agriculture of this State has always aimed at control of the San Jose scale, suggested in the letter just quoted. After the preliminary studies were completed, no one believed that extermination or eradication could be accomplished with the means at hand; but it was thought then, and is still the belief of those who are most closely associated with the work, that a control is possible, and that it was much more possible then than now, after the lapse of a period of five years.

During the progress of the inspection along the Main Line, it became apparent that more than a local effort was demanded if any substantial progress were to be made towards preventing the spread of the disease. Steps were taken to enlist the active interest of the Governor and the Legislature, (then in session). On the evening of April 10, 1911, Governor Tener sent a special message to both houses of the Legislature, calling direct attention to the situation, and asking the help of the General Assembly to combat the disease. The Governor’s message was as follows:

“Commonwealth of Pennsylvania, “Executive Chamber, “Harrisburg, April 10, 1911.

“Gentlemen of the Senate and House of Representatives of the Commonwealth of Pennsylvania:

“I have the honor to call your attention to a new and virulent disease of the wild chestnut tree, commonly known as chestnut blight, recently discovered near New York City, and hitherto unknown in America. The disease has continued to spread, destroying the chestnut trees in the neighborhood of New York City and well up the Hudson. It has invaded Long Island, beginning at the western end, sweeping eastward, practically covering the island. It has progressed to the southwest, through the whole of the State of New Jersey, and all the chestnut trees there appear to be doomed to destruction. It has entered Pennsylvania and is prevalent in the Delaware Valley. It has been discovered in the following counties: Pike, Monroe, Northampton, Bucks, Montgomery, Chester, Philadelphia, Delaware, Lancaster, and southern Berks. In isolated places it has crossed the Susquehanna, and is now detected in eastern York, eastern Perry and one portion of southwestern Perry. Other points of infection have been found near Altoona and Greensburg.

“Experiments made by the Department of Agriculture at Washington demonstrate that it is possible to prevent the spread of the disease by removing spot appearances as they are detected, and destroying the trees in which the disease occurs. By this means the region around Washington has been freed from the blight for at least two years, and it has not re-invaded this area. In the southeastern portion of Pennsylvania, where the infection is severe and almost complete, little hope exists for saving the trees, but in that portion of the State west of the Susquehanna and north of the Blue Mountains, it is hoped, by prompt action on the part of the State, to prevent further damage. If this disease can be held within the southeastern portion of the State, it will mean the saving of the wild chestnut trees in the other parts of the Commonwealth, the value of which extends into the millions of dollars.

“I therefore recommend that the Legislature give immediate attention to this important subject and that a Commission be created with sufficient power and appropriation of moneys to determine upon and employ efficient and practical means for the prevention, control, and eradication of this disease, and that said Commission be authorized, in conjunction with the Department of Forestry, or otherwise, to conduct scientific investigations into the nature and causes of such disease and to adopt such means to prevent its introduction and spread as may be found necessary.

“JOHN K. TENER.”

The next day, April 11, 1911, a bill having this purpose in view, and which had been previously carefully drawn and vigorously criticised, was simultaneously introduced in both House and Senate. This bill became a law by the signature of the Governor, June 14, 1911⁠[3]. The law creates a Commission of five members and vests them with almost plenary power to carry out its mandates. An appropriation of $275,000 became available at once. The appointment of the members of the Commission followed after an interval of about two weeks. Organization was effected, officers and assistants chosen, and on August 23, 1911, the Commission was prepared to proceed with its work.

While the major effort of the Commission from the beginning was to get a control, the subject of eradication was vigorously debated, and, as will be seen in subsequent pages, determined efforts at eradication were undertaken under the advice and direction of the Commission. The feeling was that if there be any merit in such effort, opportunity ought not to be lacking to prove it. The early announced and decisive plan involving the cutting-out method, proposed and outlined by Dr. Murrill, contributed very considerably toward the decision to try out this method.

The Murrill plan (⁠[4]) was as follows:

“Owners of standing chestnut timber within the affected area are advised to cut and use all trees, both old and young, that stand within half a mile of diseased trees, unless protected from infection through wind-blown spores by dense forest growth or some other natural barrier. This may not prevent the spread of the disease through the agency of storms, birds and squirrels, but it will at least retard its progress. Old weathered chestnut trunks that have been dead several years have no power to spread the disease, and these may be cut at leisure for the tannic acid factory or for firewood. Trees of good size recently killed should be turned into lumber as soon as possible; the fungus affects only the bark, but other fungi may afterwards impair the value of the wood if allowed to stand too long. Discarded branches and young trees of no value that are cut near the edge of the infected area should be burned at once in order to destroy the spores they contain; but if they are well within the zone of infection, such precaution is useless.”

Every element in the Murrill plan has been employed both by the Commission and by the State Department of Forestry. The fact that subsequently Dr. Murrill partially shifted his ground⁠[5], did not seem sufficient reason to warrant the abandonment of a plan of attack which in many cases was productive of satisfactory results.

The history of what work the Commission did, and of the results accomplished form the substance of several preliminary reports submitted to the Governor from time to time. The final report is what follows.

Report of

Mark A. Carleton

General Manager Pennsylvania Chestnut Tree Blight Commission

Summer condition of a blighted tree. The withered leaves of the top above the canker, and the vigorous sprouts below the canker are characteristic signs.

THE FIGHT TO SAVE THE CHESTNUT TREES; FINAL REPORT OF THE GENERAL MANAGER.

By MARK A. CARLETON, GENERAL MANAGER, PENNSYLVANIA CHESTNUT TREE BLIGHT COMMISSION.

In closing the active work of this Commission, it is a great satisfaction to be able to report constant progress to date, and the attainment of good, practical results. The work began two years ago in the midst of much skepticism as to its possibilities, but the optimism of the Commission and the wisdom of its methods of operation have in the main, been amply confirmed by the results since obtained.

PROGRESS OF FIELD WORK.

A more or less definite division has been maintained between the slightly infected Western portion of the State and the badly infected Eastern portion, known respectively as the Western and Eastern districts. In a previous report it was stated that in the Western part of the State the blight had been eradicated to the extent covering nearly one-half of the area of the State. This area so far as is known to date has been maintained free from the disease. In a few cases new infections were found which have been removed. It is important to note in this connection not only the fact that the progress of the disease has been checked in Western Pennsylvania, but that we have without much doubt prevented the blight from gaining a foothold in Ohio, and nearby portions of New York and West Virginia.

In the Eastern District since January first of this year, the field work has developed almost entirely into a campaign of utilization, no rigid sanitation work having been conducted except for the protection of chestnut orchards and nurseries.

EFFECTIVENESS OF THE CUTTING OUT METHOD.

In the two years work no facts have yet been obtained which would indicate the advisability of any change in our present method of “cutting out” diseased trees and thorough cleaning of the stumps for the eradication of the disease. A number of tracts where the disease has been eradicated by Commission employees have again been inspected recently, giving results, which are in the main, favorable. Of course, improvements have been made as to details all along. It is not a pleasant prospect to consider the serious results likely to follow after this method of eradicating the disease, conducted by the Commission, is obliged to cease.

BENEFICIAL INSECTS.

It will be of interest to quote here the words of the Forest Entomologist, of the U. S. Department of Agriculture, in his comment on a widely disseminated press notice of that Department, November 22nd, 1912, apparently based on the work of F. C. Craighead.

“The beneficial work of these insects can, however, be greatly encouraged if the owners of the timber will dispose of the diseased trees in the principal centers of infection, as recommended by the Chestnut Blight Commission of Pennsylvania, and other State and Federal officials. Thus, if the large majority of the infection is disposed of, the beneficial insects will concentrate on the remaining scattering and isolated infections, and thus more completely destroy the fruiting bodies and contribute to the protection of the remaining living trees. In fact, it is a question of the owner securing the greatest benefit from the natural agencies of control by doing his share of the work.”

NURSERY INSPECTION.

The inspection of nursery stock has been made even more rigid than before. Not only has it been required that every individual tree should be inspected by a competent employee of this Commission, but in shipping it has been required also that every individual tree should be tagged. A copy of the revised regulations governing the inspection and shipment of nursery stock is appended to this report, which shows the form of tags required to be attached both to individual trees and to bundles of trees. The fact that several of the most serious infections in the State have been caused heretofore by the planting of diseased nursery stock in new localities is sufficient reason for so rigid an inspection.

DISCOVERY OF THE CHESTNUT BLIGHT IN CHINA.

It has recently been proved by authentic specimens and artificial cultures of the material transmitted by the Explorer of the U. S. Department of Agriculture, that the chestnut blight exists in Eastern China.⁠[6] This fact makes it all the more probable that the beginning of the disease in this country may have come about by the introduction of such diseased stock from China or Japan. That new centers of infection are often started by the introduction of diseased nursery stock, is a common observation.

Winter condition of a chestnut tree with a blight-girdled top.

PROTECTION OF ORCHARDS AND NURSERIES.

It has been the policy of the Commission for sometime to protect orchards and nurseries from outside infection in all cases where the owners have expressed a desire for such protection, and have themselves taken care to control the disease as much as possible. This work has been successful much beyond our expectations. The largest and most important orchards thus protected are located at Sunbury, Paxinos, and Berwick. The owners of neighboring forest tracts have been required to remove all diseased chestnut trees within one-half mile of the nearest point of the orchard in each case. An interesting result in one of the most important of these cases is the fact that these owners have been able to sell the products of their diseased trees for an amount considerably above the entire cost of removal, sanitation work, etc.

PREVENTION OR REMEDY.

At this writing no specific remedy has been found for the disease. However, later information confirms the statements previously published that the disease may be largely prevented from entering healthy trees by constant and regular spraying with Bordeaux Mixture made up in proportions of 5 pounds of lime, 5 pounds of copper sulphate, and 50 gallons of water. The application of this mixture simply prevents any new germination of spores, but has no effect whatever, in cases where the disease has already started in the tree. Because of the cost, it is, of course, not applicable in forests.

CONTROL OF THE DISEASE IN ORCHARDS.

By cutting out the cankers and coating with antiseptic solutions and water proofing afterwards, the blight can be fairly well controlled in chestnut orchards and in certain valuable lawn or park trees. In connection with this treatment a spray of the Bordeaux Mixture as above noted should be used occasionally. Excellent results along this line of experiment are shown in a large orchard at Paxinos, and in several of the public parks of the State.

FAKE TREATMENTS, THEORIES OR CAUSES, ETC.

As often happens in the case of a public campaign against a serious epidemic, we have been constantly besieged by the gratuitous offers of various and sundry remedies for the blight, which include applications of fertilizers to the soil, insertions of flowers of sulphur and other compounds in holes bored in the trees, applications of coatings of different chemicals to the body of the tree, and numerous other treatments, all of which we believed in the beginning to have no value. However, all parties having theories to advance or remedies to propose have been given a chance to prove their claims by experimenting on trees controlled by the Commission for such purposes at Emilie, Bucks county. A number of parties have taken advantage of the opportunity. Recently, an examination was made of the various treatments by a competent Board of Reviewers, whose conclusion was that not one of the treatments tried had any deterrent effect upon the chestnut blight.

Many of the persons above mentioned were apparently sincere in the claims they made, and were simply ignorant of the true cause of the disease. Instances have come to our attention, however, of parties practicing certain methods of treatment and charging for the same, who are plainly impostors. Employees of the Commission have no doubt benefited many people by exposing the methods of these impostors.

EXAMINATIONS OF INDIVIDUAL TREES.

Excellent opportunities have been afforded the tree surgeon of the Commission and his assistants to counteract the influence of false theories and worthless remedies such as above mentioned, in responding to the numerous requests for the examination of individual trees. These requests have continued to come to the Commission headquarters right up to the time of closing our work. No other line of work has been so effective in arousing the personal interests of the people. No request from any part of the State has been ignored. In this connection much incidental advice has been given to property owners as to the general handling of lawns and orchards, and the management of small woodlots.

PUBLIC PARKS AND FARMS.

In co-operation with the officials of Wildwood Park, at Harrisburg, the Commission has completely eradicated the blight from that Park, about 150 diseased chestnut trees having been removed or treated out of a total of 1,290 trees. Here in a few cases the peeled stumps were creosoted to show that method of sanitation. Considerable help has also been given to the management of Fairmount Park. Arrangements have also been made for the entire removal of blighted chestnut trees from the State Live Stock Board’s Farm, in Delaware County. In the event of the continuation of our work, it was also planned to eradicate the blight thoroughly from the Valley Forge Park grounds.

BLIGHT-EATING BEETLES.

It has been announced by the Bureau of Entomology, U. S. Department of Agriculture, that several species of beetles have been found eating the spores of the blight fungus, and it is stated that “should these insects prove as beneficial as the observations indicate, they are certain to be an important factor in the natural control of the dreaded chestnut blight disease.” It is worthy of note in this connection that the insect investigations of this Commission have shown that a number of insects also carry large quantities of blight spores, and may thus indirectly assist in the dissemination of the blight. One of these insects which was found to carry an enormous number of spores is one of the beetles above mentioned as eating the fungus.

CORDWOOD AND THE SPECIAL TARIFF.

Since writing the last report, there has been a considerable shipment of chestnut cordwood, shippers taking advantage of the special tariff issued by the Pennsylvania Railroad. At last accounts the prospects were that there would be much business in this line right along in the future, being encouraged by the special low rates.

PROMPTNESS IN UTILIZING CHESTNUT.

Observations made by Commission employees in company with commercial lumbermen have shown that already in certain localities, diseased chestnut has been dead so long that deterioration is beginning. We have, therefore, made it plain to owners of such chestnut and have advertised the fact as much as possible, that promptness is necessary in getting rid of the diseased trees, if the owners wish to obtain the most value possible from the trees.

INTENSIVE LOCAL UTILIZATION.

Our most difficult line of work has been that of utilization. Facts as to the conditions could easily be obtained, but the difficulty has been in bringing the buyer and seller together. Recently a plan was adopted, which if we would be able to continue its operation, would without question, hasten very rapidly the utilization work. This plan, the details of which are given elsewhere, is to canvass particular localities thoroughly, finding out just what can be offered in the way of different chestnut products, ascertaining the local market for the same, and then determining so far as possible, where else the surplus may be marketed. In connection with the carrying out of this plan, up to this writing as many as a dozen portable saw mills have been located in one county, and in other localities many practical operations had already been started, thus tending to rapid and clean cut work in utilizing blighted chestnut.

RESISTANCE AND IMMUNITY.

The discovery of the chestnut blight in China makes it now all the more probable that resistant chestnut stocks may be obtained in that country. It was, therefore, a wise movement last fall when we took advantage of the opportunity to obtain a considerable amount of seed of what is probably the most important chestnut in Eastern China. A large quantity of the nuts were planted at Paxinos, and the seedlings at this date which are from six to fifteen inches high, are looking well. From the nuts sent also to the State Forest Nursery at Greenwood, 75 seedlings are at present growing, and from those sent to Asaph, Pa., there are now 182 plants, averaging ten inches in height. All of these seedlings will be of much value in cross-breeding and other ways in the important future work of developing blight resistant orchard trees. In this connection it should be noted that in a recent bulletin issued from the Arnold Arboretum a considerable discussion is given of the possibilities in developing blight resistant chestnut trees from Chinese introductions, a number of the latter now being grown at the Arboretum. The two mentioned as the most important include the one of which we now have seedlings. So far these Chinese chestnuts grown at the Arboretum have not become blighted.

According to the Kew Index, there are seven species of chestnut and twenty-one of the chinquapin in the world. From all these species there should be many other chances of obtaining blight resistant trees that may be used in breeding and making our own stock better.

CHESTNUT BLIGHT EXHIBITS.

Several exhibits of specimens showing the work of this Commission have been placed in public institutions which will remain as monuments of our work. An excellent exhibit has been placed at the Carnegie Museum at Pittsburgh. Another has been finally completed in the State Museum at Harrisburg, and a third one at the Commercial Museum in Philadelphia is not yet finished, but has been planned on rather a large scale. It was contemplated also to place another exhibit in the Everhart Museum at Scranton, which may yet be done. An excellent exhibition of specimens and illustrations of our work was made in connection with the State Forestry Exhibition at Horticultural Hall, Philadelphia, in May.

PUBLICATIONS.

When this final manuscript is published, there will have been issued the following publications of this Commission:

Report of The Pennsylvania Chestnut Blight Conference. (Unnumbered).

Bulletin No. 1—The Chestnut Blight Disease.

Bulletin No. 2—Treatment of Ornamental Chestnut Trees Affected

with the Blight Disease.

Report of the Pennsylvania Chestnut Tree Blight Commission,

July 1st to December 31st, 1912. (Unnumbered).

Bulletin No. 3—Field Studies in Blight.

Bulletin No. 4—Chestnut Blight Fungus and a Related Saprophyte.

Bulletin No. 5—The Symptoms of Chestnut Tree Blight and a

Brief Description of the Blight Fungus.

Bulletin No. 6—The Chestnut Tree. Methods and Specifications

for the Utilization of Blighted Chestnut.

Bulletin No. 7—Morphology and Life History of the Chestnut

Blight Fungus.

Final Report of the Chestnut Tree Blight Commission. Numerous

descriptive and educational circulars, charts, etc.

CO-OPERATION.

Very effective co-operation has continued to be maintained with the Office of Forest Pathology, of the U. S. Bureau of Plant Industry. Recently the salaries of all pathologists connected with the Commission have been carried by that office, and there has been constant communication and co-operation in reference to all research work.

Much excellent help has continually been given by the State Forestry Department at Harrisburg, the Deputy Commissioner, Hon. I. C. Williams, being assigned as a collaborator with this Commission.

The authorities of the University of Pennsylvania have been exceedingly courteous in granting ample space for laboratory work in the new Zoology Building. Room has also been given for laboratory work in tree medication in the Botanical Building. Franklin and Marshall College, at Lancaster, and the State College of Pennsylvania, have also provided room for laboratory work in the field investigations.

There has been a liberal interchange of ideas and helpful suggestions through correspondence with the State Conservation Commission at Albany, N. Y., the State Forester and State Pathologist of New Jersey, the State Forester of Maryland and of Massachusetts, and with officials in Virginia, West Virginia, and Maryland.

MUCH IMPORTANT WORK UNFINISHED.

The cessation of the work at this time is particularly unfortunate because so many important investigations, not yet finished, would likely have had a very practical and beneficial bearing upon the actual eradication of the disease.

First.—Very little is known about the bast miner—the insect which, as stated in another place, is probably one of the most important carriers of blight spores. A full knowledge of the life history of this insect would probably very soon have been completed, and which would be a most interesting contribution to science⁠[7].

Second.—The Chemist and Physiologist in tree medication had planned to use a new solution for injection into diseased trees, which according to chemical work already done, promises to check the growth of the blight.

Third.—The local intensive work in utilization had just begun, and as stated elsewhere, bids fair to solve largely the difficult problem of utilizing rapidly the diseased chestnut.

Fourth.—The discovery of the blight in China and the possession by the Commission of a large number of seedlings of one of the most important Chinese chestnuts, as well as immune and resistant Japanese stock, opens a field for breeding experiments which would without question have been of the greatest benefit to the owners of chestnut orchards.

Fifth.—Although not demonstrated before, it is now proved that birds and insects carry enormous quantities of spores of the blight fungus, which necessarily changes our viewpoint considerably with respect to the eradication of the disease.

Sixth.—In a number of forest tracts and several orchards, thorough “cutting-out” work and up-to-date surgery treatments have been started by expert employees of the Commission, which are just now beginning to show evidences of the value of this kind of work.

Brief statements of the results of the different lines of work conducted by the Commission follow, credited to the respective parties in charge.

FIELD OPERATIONS.

As heretofore, all field work has been conducted under the immediate direction of the General Superintendent, Mr. S. B. Detwiler. In the following statements some of the principal features of the work to date are pointed out by him, and also suggestions given to timber owners who may wish to clear their woods of blight on their own responsibility. A statement in detail of the effectiveness of sanitation cutting in controlling the blight, by Mr. Detwiler, is appended to this report.

REDUCTION OF FORCE.

A majority of the field agents of the Commission were dismissed in January, 1913, because it was believed that very little work could be done during the inclement months of winter and spring. However, the unusually open winter made it possible for the small field force retained to accomplish more for the time and money expended than at any previous time since our work was organized. An average force of 36 men in the western district and 11 men in the eastern district were in the field from the first of the year to July 25th, 1913, when all field work was discontinued.

BETTER WORK IN WINTER.

The experience of the past two years has demonstrated that more can be accomplished in locating and destroying the blight after the leaves have fallen than while the trees are in full foliage. Girdled twigs and branches bearing withered leaves are prominent at great distances in winter, and the increased amount of light admitted through the tops of the trees makes it easier to see cankers on the trunks and branches. The proper treatment of the infected trees is no more difficult in winter than in late summer or fall, unless the snow is very deep. In the badly blighted region in the eastern part of the State, field men are able to accomplish better results because most timber owners prefer to cut their timber in the winter, when they can spare the time from their farming operations.

FIELD WORK IN THE WESTERN DISTRICT.

Thorough scouting in 1912 has shown that no blight exists west of a line drawn through central Somerset and Cambria counties, along the extreme eastern border of Cameron County, to the northeast corner of Tioga County. West of this line, nine isolated spot infections were found in six counties, but all of these infections were eradicated as soon as found, and have been under careful surveillance since. These infected spots were located in Fayette, Elk, Warren, Potter, Clarion and Indiana counties, and five out of the nine spots were found to be due to the planting of diseased nursery stock purchased from nurseries in the infected region. In April, 1913, the infection in Indiana County was discovered in a shipment of three chestnut trees purchased from a nursery in New Jersey. These examples show very strikingly the ease with which the blight is widely distributed through the shipment of nursery stock. Persons who have planted nursery grown chestnut trees in regions free from the blight, should watch these trees carefully for the first appearance of the disease, and promptly destroy all infected trees.

Field work in the Western District during the period covered by this report has been confined to Tioga, Clinton, Lycoming, Centre, Huntingdon, Blair, Bedford, and Somerset counties. Tioga, Clinton, Centre, and Blair counties have been scouted and most of the diseased trees removed, but a considerable amount of infection still remains in Lycoming, Huntingdon, Bedford, and Somerset counties. In addition, Fulton and Mifflin counties still have a large amount of infection remaining, since with the small field force it was impossible to continue the work in these counties.

The accompanying map shows the progress of the control work in the Western District, and the location of infected areas. The following tabulation is a statement of the number of infected trees found and cut out in the Western District from the time the work was begun until July 1st, 1913:

Map showing spot infection in the western half of Pennsylvania to July 1, 1913, indicated by circles. Figures inside the circles indicate the number of diseased trees found in each locality.

Inspection in eastern half of the State is generalized from the best information available.

STATEMENT OF CHESTNUT BLIGHT INFECTION IN THE WESTERN DISTRICT.

County. Number of tracts on which infection was found. Total number of infected trees found. Total number of infected trees removed.

Allegheny,

Armstrong,

Bedford, 147 4,027 2,787

Bradford, 91 1,048 829

Blair, 225 1,884 1,680

Beaver,

Butler,

Cameron,

Centre, 142 2,556 1,763

Clinton, 169 3,481 2,704

Clearfield, 9 117 117

Clarion, 1 1 1

Cambria, 9 450 450

Crawford,

Elk, 6 377 377

Erie,

Fayette, 2 11 11

Fulton, 90 1,902 900

Forest,

Greene,

Huntingdon, 233 5,287 4,771

Indiana, 1 1 1

Jefferson,

Lycoming, 259 5,015 4,486

Lawrence,

Mifflin, 95 1,976 1,468

McKean,

Mercer,

Potter, 1 1 1

Somerset, 92 9,110 8,093

Sullivan, 22 207 207

Tioga, 12 43 43

Venango,

Westmoreland,

Washington,

Warren, 3 16 16

Total, 1,609 37,510 30,705

A HARMLESS SAPROPHYTE.

Persons familiar with the appearance of the chestnut blight fungus may easily confuse it with another fungus found in Washington, Greene, and Fayette counties. This fungus (Endothia radicalis Schw.), (Denot.) is related to the blight fungus (Endothia parasitica Murr.) (And.), but is found only on dead wood and bark and does not attack living tissues. It has been thoroughly studied by the field pathologist, since at first it was feared that it might have parasitic tendencies. Continued investigation proves beyond doubt that this fungus is a harmless saprophyte which need not be feared. It need not be confused with the parasitic species by those who have the opportunity to compare them.

FIELD WORK IN THE EASTERN DISTRICT.

Field work in the Eastern District has been conducted mainly on the plan outlined in the previous report. Inspections were made on the request of timber owners and advice given as to the best method of procedure in each case. Particular attention was given to assisting owners of blighted chestnut in finding the best markets for the products. On the request of owners desiring to take advantage of the reduced freight rates on blighted chestnut cordwood, inspections were made and necessary certificates issued. Supervision of enforced cutting of all blighted chestnut trees within a half mile of chestnut orchards in which the owners are endeavoring to keep the disease under control, was continued.

As the evidences of the blight become more noticeable and the seriousness of the situation forces attention, owners of chestnut timber in eastern Pennsylvania have shown an increasing interest in the work of controlling the blight, and more requests for assistance were received than could be given individual attention. For the guidance of owners who wished to clean their woods of blight, either by doing the work themselves or having it done by contract, the following suggestions were made by the Office of Utilization. These suggestions are for use in eastern Pennsylvania only, where the blight is general.

Cutting out a spot infection among large trees.

SUGGESTIONS FOR TIMBER OWNERS.

1. It is always advisable in cutting blighted chestnut to clean up the ground thoroughly and burn all infected material, for the sake of the future crop and the community as a whole. Even if financial reasons make it impossible to treat the stumps properly, the brush and refuse should be burned, and all merchantable material removed from the tract within a reasonable period. Where the percentage of blight is very high, it is advisable to cut all the chestnut trees rather than attempt to remove only the diseased trees.

2. Stumps should not be cut higher than the diameter of the tree, but this may be impracticable in sprout growth timber. A low stump saves the best end of the log, and causes the succeeding generation of sprouts to be firmly rooted.

3. Where practicable, all timber should be peeled. Poles, ties, posts and rails, should be skidded to one or more convenient places. The bark and chips collected at these points should be burned, since this refuse is very frequently the breeding place of the blight fungus.

4. It is advisable to remove all bark from the stumps down to the mineral soil, to prevent the further spread of the disease by its growth on this bark. Unpeeled stumps, even if free from blight at the time the tree is felled, are very apt to become infected, and the disease will then eventually destroy the sprouts at the base. Stumps of trees cut in winter while the bark is “tight” may be left until spring, and peeled when the sap is ascending. Stumps made in summer should be peeled at once.

5. All chestnut refuse, including the brush from the tops, bark from stumps, chips, etc., should be collected and burned at as early a time as may be done with safety from fire. Green tops of trees felled in summer can be burned immediately by close piling over a well-started fire. The danger of infecting the sprouts from the stump is lessened if the fire be made over the stump after peeling. Stumps can be more cheaply sterilized, however, by painting them with creosote, and creosote also appears to be absolutely effective in keeping the stump free from infection, whereas a fire seldom chars the base of the stump sufficiently.

6. Woodsmen, while cutting and removing chestnut, should do as little injury as possible to the remaining trees, whether large or small. When the work is done by contract, trees carelessly broken in felling chestnut should be paid for at their market value. Merchantable chestnut left in the woods, either cut or uncut, when contracts call for the removal of all of the same, should be paid for at its market value.

7. Great care should be exercised in burning material so as not to injure other trees, or allow fires to remain unwatched in the woods. Forest fires may result, causing much damage. Burning should not be done when the woods are very dry, or a high wind is blowing.

LOCAL INTENSIVE FIELD WORK.

Early in the spring a more extensive plan of field work in the southeastern portion of the State was adopted. A locality was selected where the blight is beyond control, and immediate utilization necessary to avoid serious financial loss. The boundaries of the area selected were so made that the timber in all of the woodlots in the area could be handled in much the same way as though the woodlots comprised a single tract. A map showing the exact location of all of the woodlots was made, and a field agent detailed to estimate merchantable chestnut in the form of saw logs, poles, ties, posts and cordwood in each woodlot. The local market for these products was then ascertained, to determine whether all timber on the area could be best sold locally on in outside markets. At the same time the field agent interested the owners of the woodlots in the prompt removal and utilization of their chestnut trees before greater loss was occasioned by the blight. Usually the owner of a considerable quantity of blighted trees is anxious to follow this course, but the scarcity of competent woodsmen makes it difficult or impossible. In such cases, the Office of Utilization presented the data obtained by the field agent to operators of portable saw mills, stave mills, pole or tie cutters, as the facts warranted, and as many buyers as possible were interested in locating on the area. So far as there was time to test this plan, it appears that this is the cheapest and most effective way of getting results in the eastern district, since what is desired is to get cutting started on a sane and profitable basis, and this a mere general method of work usually fails to accomplish. Success or failure depends on whether or not buyer and seller can be brought together on a satisfactory basis. The work must be profitable to both owner and dealer. A competent and well-informed field agent can work out a comprehensive plan for disposing of all the merchantable chestnut in a community. Through his knowledge of prices, rates, specifications, sanitation measures, etc., he is the means of saving timber owners from much of the loss occasioned by the blight.

DISEASE INVESTIGATIONS AND NURSERY INSPECTION.

As before reported, the investigation of the blight fungus and the nursery inspection work are under the direction of Dr. F. D. Heald. Mr. P. J. Anderson has given special attention to certain field investigations, including the work at Charter Oak. Statements of some of the principal features of the work here follow:

A Blight Infected District in Juniata County, Pa.

GERMINATION OF SPORES.

Pycnospores of the blight fungus, sometimes called summer spores, germinate much more slowly than the ascospores, or so-called winter spores. The type of growth and size of colonies are different in the early stages of development on culture media.

PRODUCTION OF PYCNOSPORES IN WINTER.

In the case of this fungus the term “summer spores” is very misleading, as these spores are produced at all times of the year, being washed down in large numbers from blight cankers following each winter rain.

BIRDS DISSEMINATE THE FUNGUS.

Careful experiments show that birds act as carriers of spores of the blight fungus. Thirty-six birds belonging to nine different species have been tested. Nineteen were found to carry pycnospores, the maximum number obtained from a single bird, (Downy woodpecker), being 757,074. The highest number was always obtained from birds shot a few days after a rain period.

“SHOOTING” OF ASCOSPORES.

The ascospores are expelled forcibly, but this expulsion depends upon temperature as well as moisture. No expulsion took place in the field from November 26th, 1912, to March 21st, 1913, the temperature during the winter rains being too low. Bark containing ascospore pustules has continued to expel ascospores for over six months, (in the laboratory).

EFFECT OF TEMPERATURE.

Pycnospores are easily killed by heat, (51°C). Ascospores are slightly more resistant, only a few being able to survive 57°C.

RESISTANCE OF PYCNOSPORES.

Pycnospores are easily killed under certain conditions, but can survive in considerable numbers under certain other circumstances. Their length of life in water depends to some extent upon the temperature. Thirty-three per cent. survived in water at 55°C, after 42 days. A large percentage can survive freezing for a considerable period. They are washed down to the ground from blight cankers, during every rain, and have never been found to disappear entirely from the soil during the longest periods between rains. As many as 12 per cent. of those originally present in a soil sample have survived drying for 63 days. The longevity of the pycnospores is greater in the “spore horn” stage than when they are separated by rains and then dried. They have been killed in twenty-four hours by drying in certain tests, while the act of drying alone is generally responsible for the death of 50-60 per cent.

EFFECT OF DRYING ON ASCOSPORES.

Ascospores when shot on to glass slides have been reported as being very resistant to drying. In nature they are generally separated and washed by the rains. Laboratory tests under such conditions indicate that they are very sensitive to desiccation. Drying alone has been found to kill as many as 94 per cent. in certain tests.

ENTRANCE OF BLIGHT IN GALLS.

A small gall on the chestnut due to a lepidopterous insect (moth) has been found to be one of the places of entrance of the blight fungus. Twenty-eight per cent. of those tested showed young blight infections.

INSECTS AS CARRIERS OF THE DISEASE.

Insects may act as carriers of the spores of the blight fungus. Of a total of 75 tested, many were found to be carrying spores. The maximum number of spores of the blight fungus (336,900), was obtained from a small beetle, (Leptostylus maculata), which has been mentioned as a possible beneficial agent on account of its pustule-eating habits.

OTHER DISEASES OF THE CHESTNUT.

There is another “canker disease” of the chestnut prevalent in the State which is entirely distinct from the blight. It is even more important as a disease of oaks than chestnut, and is known to occur on chestnut oak, red oak, and white oak. A dieback of the chestnut is not uncommon. Still another fungus appears to be associated with this trouble. A tip blight of the chestnut has also been found, and in connection with it, a third species of fungus.

FIELD INVESTIGATIONS.

A field laboratory has all along been maintained at Charter Oak, and much of the outdoor inoculation work and other experiments have been conducted in that vicinity. Experiments have been conducted here on the rate of growth of blight cankers, details of which are tabulated in another manuscript, submitted for a bulletin. It is sufficient to say here that the retarding influence of the winter season is shown by these experiments. On the other hand, the cankers have continued to spread even in the winter, though the growth is much more rapid in the summer months.

Inoculations have been made both with ascospores and with pycnospores during every month of the last year. No cankers have appeared as yet from winter inoculations.

Other species of trees besides chestnut have been inoculated with the blight fungus in larger numbers than last year, special attention being given to the oaks. As yet there is no evidence that the blight fungus will establish parasitic relation with any other host, although occasionally a canker will be produced.

Careful tree surgery experiments have been conducted at Charter Oak, and to date only three cases are reported in which the canker continued to spread after cutting out and treatment.

NURSERY INSPECTION.

The office records give the following information in regard to each nursery inspection:—date, name and location of nursery, number of trees inspected, number of trees rejected, fungicides used for dipping the stock, name and location of purchaser of stock.

The nurseries from which chestnut stock was shipped during the fall of 1912 and spring of 1913, are as follows:—C. K. Sober, Paxinos, Pa.; Hoopes Bros. & Thomas, West Chester, Pa.; Lovett Nursery, Emilie, Pa.; Rakestraw & Pyle, Kennett Square, Pa.; Morris Nursery, West Chester, Pa.; Cheltenham Nursery, Oak Lane, Pa.; Jos. Moore, Montoursville, Pa.; S. L. Cummings & Co., Dewart, Pa.; and Marietta Nursery, Marietta, Pa.

In the fall of 1912, 6,538 trees were inspected. Of these 81 were rejected, and the remainder 6,457, distributed. In the spring of this year 5,305 trees were inspected, of which 195 were rejected and the remainder 5,110 distributed. The trees rejected were either infected with chestnut blight, or showed doubtful incipient infections. In case of doubt the inspectors were instructed to reject the tree. The number of rejected trees, however, is no indication of the percentage of blight in any nursery, since many diseased trees are removed from the nurseries previous to the time of making shipments, and only those thought to be healthy trees are offered for inspection.

Probably the greater portion of the trees went to purchasers in either Pennsylvania or New York. In case of re-distribution by other dealers, however, the final destination of the stock is not known. According to available records, the trees were sold to purchasers in the following States.—California, Colorado, Connecticut, District of Columbia, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maryland, Michigan, Missouri, Nebraska, New Hampshire, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Texas, and Wisconsin.