Prof. J. Franklin Collins, Rhode Island

The chestnut blight has now been with us for more than twenty years and has destroyed practically all the chestnut trees of the northeastern part of the country. It has spread in all directions from its original center in the immediate vicinity of New York City until it has reached the limits of the native chestnut growth in the northeast and north, and is steadily approaching its limits in the west and south. The disease, a native of China and apparently imported into this country on some Japanese or other oriental chestnut, found a more susceptible host in our native chestnut and so became a virulent parasite on this new host. It was not until 1904 that general attention was attracted to the disease. By that time it had obtained a strong foothold on the chestnuts of southeastern New York (particularly the western end of Long Island), in southwestern Connecticut, and in northern New Jersey.

All of you are more or less familiar with the efforts made in Pennsylvania, New York, and elsewhere in the northeast, in co-operation with the federal government, to control the disease. These efforts are now an old story to most of you and there is no need of repeating it at this time.

Early in the fight against the blight the attention of many of us was directed to locating possible immune or resistant species, varieties, or individuals. The search for resistant native individuals and the accompanying experiments in crossing and grafting various species and varieties has been kept up ever since. Foreign explorers have constantly been on the lookout, with more or less success, for chestnuts in other countries that might be resistant to the blight. It has long been known that most forms of the Japanese chestnut (C. crenata) were in general highly resistant to the blight. Later it was found that the more recently introduced Chinese chestnut (C. mollissima) was also quite resistant, although both the Japanese and the Chinese were far from being immune. Quite recently Mr. Rock, explorer for the U. S. Department of Agriculture, has brought a new chestnut from southern China for experimental purposes. Notwithstanding newspaper reports to the contrary the possibilities of this chestnut in this country apparently are unknown at the present time. Nobody seems to know if it will stand our climate, resist the blight, produce worthwhile timber or fruit; nor is its name known, according to late advices that have reached me.

Some years ago the late Dr. Van Fleet made numerous crosses between the Japanese and the American chestnuts, the Chinquapin, and other species and varieties. Personally, I have not been in very close touch with Dr. Van Fleet's experiments. Doubtless some of you know more about them than I do. Regarding these I will only say at this time that the work begun by Dr. Van Fleet is being continued by the Federal Bureau of Plant Industry, with Mr. G. F. Gravatt in direct charge of the work so far as the Office of Investigations in Forest Pathology is concerned. Mr. Gravatt is also testing out the value of scions taken from seemingly resistant native trees when grafted on resistant stocks.

Some years after the blight had destroyed most of the chestnut trees in the northeastern states we kept getting reports from various localities to the effect that the blight was apparently dying out. Many of these reports came from sources that made us doubt their value, but others came from more reliable sources. We have had opportunity to investigate a number of these reports and have usually found that the statement that the blight was dying out was, in a sense, strictly true, the reason being that the chestnut trees were entirely dead, except for sprouts. This fact naturally prevented the disease from showing us as much as in former years.

Some twelve years ago I noticed in Pennsylvania a sprout of an American chestnut about an inch in diameter which had a typical hypertrophy of the disease, apparently completely girdling the sprout at its base; also a girdling lesion farther up on the stem. The hypertrophy was such a pronounced one and in other respects such a typical example of the disease that I photographed it. A few years later I was surprised to observe that this sprout had increased to more than three times its former diameter and that the two diseased areas just mentioned apparently had disappeared—at least they were no longer in evidence except as rough-barked areas. To make a long story short this sprout is still alive and has increased in size and height each year. Although now (1924) it is considerably branched and makes a small bushy tree it is badly diseased in numerous places and is only partially alive, but the dead portions have not resulted from some half dozen of the original disease lesions (apparently girdles), but from later infections. The very fact that a sprout should have lived for more than twelve years in the center of one of the most badly diseased areas known to the writer seems at least to suggest the possibility that future chestnut sprouts may yet grow in spite of the disease and persist—at least in a shrubbery form if not as a tree.

The sprout to which I have just called attention is not an isolated case, but merely one of the most pronounced that I know about. In a careful survey in July (1924) of the region immediately surrounding the sprout just mentioned two or three other notable, but less pronounced, cases of a similar sort were discovered. In two cases fine looking branched sprouts some twenty feet high with healthy-looking foliage were noted. Both were diseased but the disease seemed not to be very conspicuous or virulent. In a recent survey of woodland in Rhode Island (July, 1924) much healthy foliage was observed and several large sprouts were found on which the disease (although present) seemed to be doing little damage when compared with its former virulence in the same general region.

I call attention to these cases primarily to acquaint you with the results of our latest observations on what seems to me to be cases of gradually developing resistance in some of the remaining sprouts. In all my intensive work on the blight between 1907 and 1913 I cannot now recall a single instance where a chestnut sprout in a disease-ridden area ever reached a diameter of an inch or thereabouts before its existence was cut short by the blight; and yet today—a dozen years later—we are finding quite a number of living sprouts over two inches in diameter, and a few that are three, four, and even up to seven inches in diameter. Last Friday, August 29, I heard of a small chestnut tree in New Jersey that bore a few burs last year and which has a dozen or more this year. If the nuts mature we hope to get some of them to propagate. Last Sunday, August 31, I saw a three inch sprout in Connecticut that had had a few burs on it. I would be glad to learn of any cases of this sort that may come to your attention.

You are all thinking men and women and all of you have had experiences with diseased trees of some sort, many of you with very serious diseases, and some of you I know have had a wide experience with the chestnut blight, so you can draw your own conclusions as to the significance of the facts that I have stated.

As to the state laws for transporting material from one state to another I am not posted, but I believe that we can be advised by writing to the government at Washington.

DR. MORRIS: We do not know whether the Washington government will sterilize those scions and send them out for us, but there should be some way of sending from one state to another.[B]

It seems to me that in all probability, the vital energy of the protoplasm of the endothia is diminishing. Quality, flavor, or anything you please, is bound up with certain vitality, and that diminishes and finally will cease. That is the reason for the endothia growing less now.

PROF. COLLINS: My point was perhaps not exactly that. I meant that the result is that, with the average cases, we are now getting chestnuts not so quickly destroyed. The explanation may be exactly what you have stated.

DR. MORRIS: There are two factors to be considered. First, the running down of the vital energy of the protoplasm; and second, in the factors which affect the vital energy of the plant.

PROF. COLLINS: In the paper I have just read there was mentioned the apparent number of trees in various parts of the country which are very slowly dying from the blight, and some which have resisted it entirely, so far; but that was not the point I desired to emphasize. There are some around New York City which are still growing, and Dr. Graves could tell us of this.

MR. O'CONNOR: Would it be desirable to take out an old tree where there are new sprouts? One tree on Mr. Littlepage's place in Maryland has a number of sprouts coming up. I suggested that if we could get people together and clean the woods up we could dig up the old trees and only leave the blight-resistant ones.

PROF. COLLINS: That is near Bell Station where we do our experimental work. We found one place infected. I cleaned it out and we have not seen anything of the disease since.

MR. BIXBY: Some five or six years ago I sent a number of chestnuts to Warren, New Hampshire, which is outside of the blight district. I did not know then much about the blight. They grew for several years and it was not until one year ago that the trees were found with blight. I got the party to cut them down. How long must I wait before it is safe to send other trees there? I believe they will grow there and bear, but we do not want to get them affected with the blight.

PROF. COLLINS: I do not know that anybody could answer that. Apparently we have waited 20 years and are still unsafe. It is a case of experimentation.

MR. KAINS: As to the hybrids of Dr. Van Fleet and Dr. Morris, in the spring of 1923 I planted 10 and there are only four alive now. They were affected by blight and killed. They were rather large trees when planted, and I think for that reason more susceptible. We had the idea from the nursery that they would be more likely to withstand the disease than would the American sweet chestnut. Have you any reports as to the way these hybrids behave?

MR. REED: As to Dr. Van Fleet's hybrids, so far as we know they are all going with the blight. The collection in Washington is practically gone. We are still caring for them and doing what we can but the prospect is not at all good. We get reports of these distributed around the country, but in no case have we had a report indicating that the Van Fleet hybrids were at all resistant.

[Footnote A: Note—"Blight-resisting" as used in this paper should be interpreted as a slower death of the host than in former years, whether or not the result of increased resistance to the parasite on the part of the host, or to decreased virulence of the parasite, or to both factors combined.]

[Footnote B: Decision From the U. S. Department of Agriculture.
Washington, D. C.

In a letter of later date, addressed to Mr. C. A. Reed, Dr. B. T. Galloway, of the U. S. Dept. of Agr., wrote regarding the matter of distributing Merribrooke chestnut scions, as follows:

"I have talked with Mr. Stevenson, of the Federal Horticultural Board, regarding this matter, and he says that, while there is no federal quarantine covering the chestnuts, as a matter of policy we have not been letting any chestnuts or scions go through our hands into the non-blight regions. Mr. Stevenson says that Dr. Morris himself might be able to carry out the plan he suggests by dealing direct with some of the state institutions in non-blight regions, selecting states that have no quarantine against chestnuts."]

PROF. COLLINS: I will now read my paper on