Chapter II: Part 2

Mr. Roper (Virginia): I think it does, but that is discussed in a paper which I shall read some time here in the meeting. Both the Stuart and Moneymaker have done better with us than any other of the southern varieties when they are budded on hardy stocks. The grafted trees do not do well with us.

President Morris: Professor Lake, will you speak on any of these points?

Professor Lake: I am learning much and prefer to continue a learner. I shouldn't know anything about this crossing, except in the case of the _Juglans regia_ and the oaks of California. That is one case that was not mentioned. We have a remarkable hybrid between the native oaks and the Persian walnut. It is remarkable in many ways. It has foliage that is perhaps half way between the oak and the walnut, and the nut on the surface looks like a small walnut, and on the inside it is between a walnut and an acorn. I had an opportunity to sample the flesh, but it is not edible yet. They are interested in the work very much, especially at Chico and the Southern California Station.

President Morris: It is said to be a cross between the live oak and the walnut. It seems absolutely impossible, but I have seen the nuts, and a photograph of the tree.

Mr. Reed: We haven't devoted a great deal of attention to the hybridization of nuts in our Department work. There is one thing that occurred to me, as I sat here, merely of passing interest. A gentleman in Mississippi sent a specimen of foliage, together with berries, from what he said was a hybrid between the pecan and the China berry; and he had the evidence, because the parent pecan tree stood right there, and the China berry was the other parent tree! He wanted world wide attention called to that. They were taken to the botanist, and he recognized them as one of the ordinary soap berries. There was a similar case this fall. A gentleman in Texas exhibited some nuts at the State Fair at Dallas that he said were a hybrid between the mocker-nut, the common hickory there in Texas, and the pecan. He said that the parent trees stood near one another and that the pecan blossomed some years about the same time that the hickory did, and in those years the hickory nut was long, and in other years it was short. Somebody sent one of the nuts to Mr. Taylor, Assistant Chief of the Bureau of Plant Industry. He sent the nut on to me, and I looked it up. I struck Texas on one of those cold wave days, and drove five miles out and back in a Texas livery rig, and found an ordinary hickory that bore nuts just a little different from others. That is one way the Department is called upon to ferret these things out.

Mr. Littlepage: I would like to ask Mr. Reed what information he has as to the success of pecans bearing when grafted or budded on other varieties of hickory? I say that because I know from traveling around through the country that there is a widespread impression that it is possible to have very extensive pecan orchards throughout the North by topworking the wild hickory. I have had some little experience along that line, but I don't know what the facts are; and Mr. Reed has made an extensive trip recently for the Department of Agriculture, collecting data in reference to the pecan.

Mr. Reed: The present situation, so far as we have been able to gather the information, is just this. The pecan has been grafted on a good many species of hickory, all the way from Virginia south to Florida, and west to Texas; but rarely ever can we find an instance in which they have produced satisfactorily after they have come to a bearing stage. We find that they unite readily ordinarily, and grow rapidly; but the pecan eventually proves to be a more rapid grower than the hickory, and when it catches up and is the same diameter, then the pecan growth is slower, and while they bear a little the first few years, later on they are not productive. I don't wish to say that is final, but it has been the experience so far. You will find most enthusiastic advocates of pecan on hickory where it hasn't been tried for any length of time. The men who try it find it unites readily and makes this quick growth, and think the question is solved. But aside from a few instances in Texas, I don't find very encouraging reports. It may be due largely to the fact that the right varieties of pecan haven't been used. We know that in the early history of pecan culture the Rome and Centennial and some others that are light bearers were used; and then the pecan on hickory has been looked at as so much saved, and they haven't been given much attention. It is still very much a matter of doubt, but is not in a very favorable light at present.

Professor Craig: I would like to ask Mr. Reed if he has looked over Mr. Ramsey's work recently at Austin, Texas.

Mr. Reed: I was at Mr. Ramsey's last year, and I don't recall that that matter came up at all.

Professor Craig: Didn't you see his plantation of top worked hickories?

Mr. Reed: I didn't know he had topworked hickories. He has topworked pecans. Professor Kyle of the Station in Texas has recently issued a bulletin on that very thing, and he cites a number of cases in which he concludes that there will be a favorable outcome; but for some reason, in the instances which he cites, the trees haven't borne very much. They attribute it this season in one instance to the fact that they had a storm at pollinating time, and last year some other accident happened that prevented them from maturing after a quantity of nuts had set.

Mr. Littlepage: I mention this at this time because I want to get Mr. Reed's testimony in the record, because I think that every prospective nut grower must go through this stage. A year ago I undertook on my farm in Indiana to bud the pecan into other varieties of hickory--I have a great many wild hickories growing all over my farm,--shagbark, shellbark, and different varieties of those even. So I went to work and budded perhaps one hundred of those trees, and for a while it seemed that there was going to be a great degree of success. I budded them all upon the limbs where the bark was thinner, and tied the bud in with waxed cloth very tightly; and by absorption the majority of the buds lived a week or ten days. After that, there was perhaps a third of them alive. For the next two weeks, we could find an occasional bud that remained green, and then the number became so very small that I gave up the idea that any would live. But this spring I found a few of these had started to grow, but I had tied them so very tightly that in some instances where there had been a growth of an inch or two, the bud part had been cut in two. Then I undertook it on a much smaller scale. I cut back eight or ten small hickory trees three to four inches in diameter, let them throw up water sprouts, and budded into these. The bud wood I used stuck very tight, and I examined the buds in November, and there were quite a number alive of the Greenriver and Huntington varieties of pecan. Whether they will grow finally remains to be seen.

(A discussion then occurred as to holding the afternoon session and
it was decided to continue the business during the afternoon,
instead of visiting the Campus.)

President Morris: I would like to comment on one point made by Mr. Littlepage. He has given us perhaps the reason why pecans die back when grafted upon other stocks. Mr. Reed, that is an extremely important point. He has shown that the pecan grows so much more rapidly than other hickories that when it has arrived at a proportion to be supported by the root of the other hickory, it then ceases bearing because all the energy is required for maintaining this new pecan top that tries to grow faster than the hickory, if that is my understanding of this point.

May we not graft freely back and forth hickories of kinds which have about the same rate of growth, and may we not graft other kinds of hickories upon pecan stock, for we don't care how much nourishment is given to a fine young shagbark?

Mr. Littlepage: That is a fine point.

President Morris: I am very glad Mr. Reed brought up that point. It is going to save thousands of dollars if it is a fact recognized in time, because many would go to putting pecans upon other hickories. We may learn that certain kinds of hickories can be grafted to advantage upon other stock, however.

Mr. Reed: There is another point right there I would like to have your views on, and that is, the smaller the hickory is at the time the pecan is grafted on it, the greater will be the influence of the pecan on the hickory.

President Morris: It can drag the stock along perhaps. It has been proved, I think, that a graft has a certain influence upon the stock, and in some cases can drag it along willy nilly to a certain extent. The root and the top get to balance each other fairly well if the root is very small at the time the graft is put on. Most of the trees that have been topworked to pecan have been various kinds of large hickories. Perhaps if you were to take a shagbark hickory one to two years of age and graft it, the pecan top would dominate or control that root, no matter whether it wanted to grow or not.

Mr. Reed: The claim is sometimes made that if the pecan is grafted on other hickory young enough, it will transform the hickory completely. It will make a sufficient root system to feed the pecan as well as the pecan root would. But I have never seen that demonstrated.

President Morris: That is speculative. It is a very valuable point, one of the sort of points that would naturally be brought out at a meeting of this kind.

Mr. Reed: Have you seen that with other fruits, Professor Craig?

Professor Craig: Yes. Each variety of apple produces its own kind of roots without reference to the seedling stock. That is to say the scion overrules the root in budding or grafting upon one or two year old seedlings.

President Morris: A parallel that comes to mind now is the grafting of Burbank's Royal walnut upon ordinary walnut stock. When that was done, his Royal walnut was said to drag the other walnut along.

Professor Craig: I think it is a very valuable suggestion. I am not sure I will go as far as the President has gone; but I think it is exceedingly suggestive, and worthy of careful consideration.

Mr. Rush (Pennsylvania): I find the same experience in some instances, that the graft outgrows the stocks. That is a peculiar instance of the work of improper unions. Eventually the stock pushes up and forms a perfect union in growth, with the Persian walnut. This is particularly applicable to pecan and hickory. I suppose Mr. Reed will bear me out in that, with regard to English walnut and black walnut.

Mr. Reed: Oh, yes.

President Morris: You occasionally see a variety of apple grafted on another in which the graft part gives the tree a sort of slipshod appearance. How about the bearing in that kind of a tree?

Professor Craig: They usually bear heavily where the food supply is restricted.

Mr. Reed: That would make our pecans bear more heavily on hickory stock than on their own.

Professor Craig: As a matter of theory, they ought to. The bearing ought to be increased, because it is a system of girdling, or brings about the same effect,--in other words it restricts the return flow of the elaborated food. The food is checked at the point of union. Another parallel is in the case of _Prunus domestica_, the European plum, when worked on _Prunus Americana_, the American plum. In that case, the top always outgrows the stock, and in ten years it presents a very curious appearance. It presents the appearance of a very top-heavy head on a very spindling stem. The bearing is usually encouraged, but the fruit is usually small. The amount of fruit measured by numbers is increased, but the amount of fruit measured by the size of individual specimens is decreased.

Mr. Collins: Isn't the size of the fruit increased in the case of apples?

Professor Craig: By topworking, usually, it is, but that doesn't contemplate such an extreme case as that. It means when the union is reasonably uniform, when there is a reasonable affinity between stock and scion. But in extreme cases we get the opposite result. Reproduction is encouraged, but size of fruit is checked.

President Morris: I would like to hear from Mr. Rush or Mr. Pomeroy in connection with the hickory.

Mr. Pomeroy: I haven't ever tried any experiments with the hickory.

President Morris: We will discuss further some of the points that have been suggested in this paper, because it seems to me we are along a good line of cleavage, and this line of cleavage may dispose of some questions that we haven't discussed. One question brought up was if the bitter, astringent qualities are likely to be recessive among hybrids in the trees which have bitter nuts.

Mr. Littlepage: I made a trip through Missouri and Arkansas a year ago, and while there, took occasion to go into the forests, and investigate to some extent the Arkansas and Missouri hickory and pecan. Among other things, I found two hybrids, one of the pecan and one of the pignut, one of which was bitter and inedible, the other a fairly good nut. I have both of them with me here today. One of them was very astringent and bitter, the other had taken more the quality of the pecan as to meat, and was a fairly good substitute. I don't know what the reason for it is, that one is fit to eat, and the other isn't, when they are both hybrids between the pignut and the pecan.

Doctor Deming: How did you know they were hybrids, by the appearance?

Mr. Littlepage: Yes, the appearance is unmistakable. The pignut characteristics are very prominent, also the pecan characteristics.

President Morris: Have the members anything to say about the Stringfellow method of transplanting hickories?

Doctor Deming: I have had very little experience in transplanting hickories, but I set out two Hales hickories I got from Meehan, and they are both living, although they have made little growth in some three years. Can you tell us what stocks the Hales hickory is grafted upon?

Mr. Brown (Pennsylvania): Upon the bitternut. All there are have been upon the bitternut from the start.

Doctor Deming: Mr. Littlepage, what do you think of the future of topworking our seedling hickories in the North with improved varieties of hickory or pecan,--the commercial future?

Mr. Littlepage: It is largely speculative. I suppose it is the province of every nut enthusiast to have an opinion about these things. In fact, I find it is encouraging to talk to the fellow who has an opinion. My notion is that there is a great future for topworking the various varieties of the hickory in the North to the desirable forms of the hickory, that is, of the hickory other than the _Hicoria pecan_. On my farm I expect next year to devote some time to topworking the various hickories I have to the desirable varieties of the shagbark. I think that can be done throughout the whole country. The shagbark seems to be indigenous to such extensive latitudes, that it seems to me there are great possibilities along that line. I observe that around here we find many of those trees. I have some very beautiful shagbarks that came from Canada. My opinion is that it will be successful. I think the reason the pecan has not proved very satisfactory upon the other species of hickory is that most of those hickories have a close grained wood, and that the distribution of available food depends largely upon the amount of sap. The _Hicoria pecan_ is a much coarser grained wood. The flow of the sap upward is facilitated much more than the flow of the sap upward through the hickory stock of other varieties. I believe that is the reason the theoretical rule would probably not work in this case, simply because the distribution of sap cannot take place fast enough through the tight, close grained stock of other varieties of hickory. Otherwise, I don't see why the rule would not obtain, as with fruits. The experiences Mr. Reed gives, I think, are generally recognized by those who have experimented with them to any extent. I noticed in visiting Mr. Roper's nursery he had one very beautiful specimen of the pecan grafted on a hickory. That was the Stuart, was it not?

Mr. Roper: The Moneymaker. It had made a growth of four or five feet in two years.

Mr. Littlepage: Do you know the variety of hickory that it was topworked to?

Mr. Roper: Just our common hickory, I suppose the pignut.

Mr. Littlepage: It made beautiful growth from the wood standpoint.

Mr. Roper: Mr. Reed's point was that it would do that till it got by the period of good nutrition from the root. Professor Craig says the elaboration of food from the pecan top more than overcomes the deficiency.

Professor Lake: I would like to question Mr. Littlepage's physiological ground for the lack of proper fusion of liquids between the pecan and the other hickories. I believe it is not authenticated that the water supplies from the earth would not distil as fast in the close grained hickories as in the more open grained pecan. At least, the very close grained, firm woods of the tropics transmit a tremendous amount of water, much in excess of many of our fine grained woods of the North. And it seems to me I wouldn't like to have this Association go on record as vouching for this explanation exactly. It seems to me there are better explanations. Lack of fusion is not due to the amount of water that is carried up, but rather to the fact that the root system of the hickory does not develop fast enough to collect water to transmit.

Mr. Littlepage: I am very glad to hear Professor Lake's statements. My suggestions were given only as a possible theory that occurred to me, and I don't vouch for their accuracy. There must be some explanation to controvert the general rule which Professor Craig has given us.

Professor Craig: May I add one word? When a stock and scion unite, the union is really a mechanical one. It is a union of cells, and in that respect it is simply mechanical, not a physiological union. The different life types or character of the scion and top do not fuse, but we have a mechanical union of cells, and that mechanical union is as clearly shown forth as possible when we make a section through the point of union. If your type of cell in the stock differs very materially from the type of structure in the scion, the union is unsatisfactory. If the types of tissue are much alike, the union is good and you do not have either overgrowth of stock or undergrowth of scion very much, but you have what is called a good union. It is to some extent a question of mechanics, in my judgment, influenced by the cell structure of stock and scion. If you have a good, smooth union, the two grow equally. Where you have overgrowth of scion, you usually have a starved root, because the food which is to be returned elaborated is checked at the point of union, the root is starved, and you have a short lived tree, because your root system, which ought to receive its share of the distributed food, is underfed, finally weakens, and the whole structure fails.

Professor Lake: You may have mechanical union, but you can't have the after fusion in which you are going to have proper function of stock and scion.

Professor Craig: Each cell functions after its own kind. It is a question of passage or transmission of food through that carrier, after the union is effected. If the character of the two types differs very much, the transmission of food is checked and is difficult.

President Morris: There is another mechanical point I'd like to ask about. When the two types of cells differ, will the difference in degree of capillarity regulate the amount of pabulum distributed, or does it depend upon negative and positive pressure?

Professor Craig: That is a very difficult question, because it isn't settled at the present time what credit we should give to capillarity and what to root pressure in sap circulation.

Mr. Reed: There is another question I would like to ask Professor Craig. Supposing you have a mechanical union perfected, what is the difference in the food that different species of the same genus transmit? Has that been worked out?

Professor Craig: I don't think so. Of course, there is a difference in the food. That is proven, because there is a difference in the quality of the food. The tree machine, the tree factory speaking individually, evidently makes different products, and that is shown by the different quality of nuts. That is all we know about it.

Professor Lake: That part below the scion still continues to be normal hickory, and that part above, pecan, so really it is not a matter of distribution of water supply by gravity or other pressure, but rather a distribution of the proper amount of elaborated food; and that is transmitted through the cell itself, not the cell walls. Because this top makes a food that is different from the normal requirements, or because the latent character of those cells below does not respond to the food supply as actively as the part above, is the whole question, it seems to me. If the cells below functioned as the cells above, there would be no question about the stock and scion being the same.

Mr. Littlepage: Of course there must be sufficient flow of sap to distribute food. The hickory root might not send the flow of sap as fast as the pecan top would like.

Mr. Reed: Is Mr. Lake's point always true, that the stock below the point of union remains a normal hickory?

Professor Craig: I don't believe there are more than one or two exceptions noted to that, and those exceptions are recorded under graft hybrids.

Mr. Reed: A seedling pecan tree owned by Mr. B. M. Young of Morgan City, Louisiana, was top worked with scions from the McAllister hican some seven or eight feet above ground, and later on the bark of the pecan trunk below the point of union became scaly like that of the hican above.

Professor Lake: That would suggest something worth while, if that part below would produce fruit like the part above, but I would want to question a little the modification in bark characteristics being a direct result of cross grafting.

Mr. Reed: Of course, it was no check--only one instance.

Professor Craig: There are one or two others that are authentic. I have known a case of plum. Here we have the plum stock, we will say it is _Prunus Americana_, grafted with _Prunus triflora_, the Japanese, then later on, _Prunus domestica_ is put on top. I have seen a sprout from triflora bearing Japanese plums, while the top of the tree bore _Prunus domestica_, although there was only a small section of stem in there between our two distinct species. They were perfectly normal.

President Morris: Each elaborates its own kind of food in its own kind of cell. I would like to hear from Mr. Brown and Mr. Wilcox on this matter of grafting--the influence of stock on scion.

Mr. Wilcox: We had a good show of stocks, but instead of allowing them to become established in the pots, we grafted them as they started into growth after rooting. Had they been established, we would have expected better results.

Professor Craig: What method do you employ?

Mr. Wilcox: Side grafting.

Professor Craig: Do you mean whip grafting?

Mr. Wilcox: Side whip grafting.

Doctor Deming: I would like to ask Doctor Morris what he thinks of the practical future of grafting our hickory seedlings with improved varieties of hickory or pecan, and the method most likely to succeed,--whether grafting or budding, and at what season. It is important to learn whether we can so graft or bud our hickory sprouts that within a few years we can hope to get something from them.

President Morris: We can only make a parallel with the pecan. If we know that it requires fifteen or twenty years for coming into bearing as a seedling tree, and if we know that it bears frequently in two, three, or four years after being grafted we can anticipate analogous action with other species of hickories. I haven't been able to get testimony from men who have grafted hickories. One man told me he thought shagbark grafted upon other shagbark, topworked, came into bearing in seven or eight years. Another man told me that his came into bearing in a much shorter time than it would otherwise, while with one particular variety, the Hale, I think that twelve years has been required for the tree to come into bearing.

Doctor Deming: I have a communication from Mr. Hales in which he speaks of a tree grafted in 1880, but doesn't say when it began to bear.

Mr. Littlepage: He told me it has taken some of them twenty years.

Doctor Deming: But the pecan on hickory has been known to bear the second season, that is, topworked. Can we expect such results in topworking our own hickories?

Mr. Littlepage: I think so.

Doctor Deming: Are we going to have success in topworking, and by what method?

President Morris: I believe in the South they can graft, but in the North we have got to do it by budding. My best results have been late July or early August. I believe herbaceous budding promises a good deal.

Mr. Rush: Were those buds then of the year previous?.

President Morris: Those were buds from the year of the scion, and herbaceous stock of the year.

Doctor Deming: Mr. Littlepage has had some success in budding hickory very early, haven't you?

Mr. Littlepage: I was just stating that I started in last year to bud. I think it would be possible to make a pecan orchard bear early by budding into these hickories, ten, fifteen, or twenty years old. This next year I am going to try hickory on hickory. I am going to try three processes. I am going to try bark grafting, and whip grafting in the body of the tree which has been cut off. Then, I have quite a number of hickories each four or five inches in diameter that I have sawed off and allowed to put up clusters of water sprouts, and I am going to whip graft some and put paper sacks over them, and see which is the best.

President Morris: I have found budding the best.

Mr. Reed: Doctor Morris referred to the analogy of the pecan grafted on pecan as coming into bearing in two years. Do you account for that in the fact of its being a graft, or the fact that the wood you selected came from a tree that had the characteristic of early bearing?

President Morris: No doubt that characteristic was transmitted, and further, no doubt the grafted stock was used from bearing wood. Those points are all of interest.

Mr. Reed: Does the mere operation of grafting or budding influence earliness of bearing?

President Morris: Yes, if I understand the question rightly. A tree that might not bear for fifteen years as a seedling may bear in three years grafted.

Mr. Rush: I have Persian walnuts that bore two fine nuts the second year. I have young trees, one about thirty inches, and I am sure it will be full of nuts next year, unless some providential misfortune should intervene.

Mr. Reed: At what age did the original trees begin to bear?

Mr. Rush: Those were buds shipped to me from California.

Mr. Littlepage: I am firmly convinced that there is something in the process of budding or grafting that stimulates the growth. For example, I have scions that were not over four to eight inches long grafted on one year seedling pecans which, at the end of this season's growth, were as much as thirty inches high. All along in the same row where seedling pecans were not grafted, there is none over eighteen inches high.

Mr. Reed: To have made exact comparison, you would have had to take buds from your seedling nursery trees, and graft on other trees. You are comparing these buds from one tree with seedlings of another.

Professor Lake: I would like to ask if you didn't bud or graft the best stocks in the row too?

Mr. Littlepage: We took the whole row, as we came to it, but that particular tree might have been on some particularly favorable stock. It is a matter of a good deal of interest to see why a seedling which wasn't budded at all didn't grow as high as a scion which was budded in summer, stratified all winter, then put into the ground in an unnatural position.

Professor Craig: It is the same principle, I think, which we discover in pruning. If we prune heavily during the dormant season, the effect is increased vegetative growth. If we wish to stimulate the growth of an old tree somewhat debilitated, we go to work and cut off a large portion of the top. We don't disturb the root. The effect is that with the same amount of pushing power from the root, we have a decreased area over which that energy is spread, and it results in apparently increased growth. I am not quite sure if we were to measure it up in a scientific way, we would actually find it was increased growth. There are fewer branches, but they have made greater length. In the case of grafting our pecans, we cut off our tops, set a two-bud scion in the root, and usually but one starts and receives all the vigor from the established root, instead of the vigor being distributed over several buds on the original seedling top. We have as a result of that concentration of vitality increased growth. I think that theoretical explanation will stand fairly well, because it seems to be directly in line with the effect of winter pruning.

Mr. Reed: I would like to ask Professor Craig to what extent he would select seed for nursery purposes? What influence would the characters of the parent tree from which the seed came have on the grafted tree?

Professor Craig: I don't believe that we can expect the characters of our stock to affect the scion to any extent. I think what the nurserymen should have in mind and keep in mind is a good, vigorous stock, and as many stocks as possible,--as he can get out of a pound of nuts. Otherwise, I don't think it cuts much figure. In that connection there is a principle which I have discovered by experience, namely, that if you are growing stocks it is wise to get your nuts as near your own locality as possible. My experience last year in planting five hundred pounds of northern grown nuts in a southern locality, and five hundred pounds of southern grown nuts in the same locality, gathered in that locality, is that I got fifty per cent more trees from my southern grown nuts than northern, and trees that were fully thirty per cent better.

Mr. Littlepage: Where were your northern grown nuts stratified?

Professor Craig: They were not stratified. They were planted as soon as they were received, and they were received within two weeks from the time they were taken from the trees.

Mr. Littlepage: I am inclined to believe that if your northern grown nuts had been stratified in the North, and undergone the customary freezing and thawing, then had been taken up in the spring, you wouldn't have seen that difference.

Professor Craig: I think that point is well taken.

President Morris: There is no doubt about that. In that same connection--I would choose nuts for seed purposes of a mean type, for the reason that nature is all the while establishing a mean. The big pecan is a freak. If you plant big or small nuts, you don't get big or small nuts in return. You get both big and little seeking a mean.

Mr. Roper: The large nut will give a better tree. We have tested that out.

President Morris: Does that work out logically in that way, is it a comparative matter all the time?

Mr. Roper: We haven't worked that out in the bearing, but in the nuts in the row, the small nuts did not produce as large trees as the large nuts. We never tested the mean nuts. We did select some of the very smallest we had, and planted one of the northern and one of the southern type. They came up, but the trees amounted to nothing.

President Morris: The idea I meant to convey was that both very small and very large nuts are freaks, and neither likely to give as good a tree as mean types. What would you anticipate, Professor Craig?

Professor Craig: I think that would resolve itself on a practical basis from the practical standpoint. I think the mean or average sized nut would give you the best results. There is no doubt, as Mr. Roper said, the very small nut would give you weak seedlings. On the other hand, you couldn't afford to use the very largest, so that a mean between large and small would be the natural thing to choose. But we should do nothing to discourage the planting of the finest specimens, with the possibility of getting something unusually good. That is certainly the work for every amateur.

Professor Lake: Does that statement, that you think it doesn't make much difference about the parent of the nuts for stock, apply to walnuts?

Professor Craig: I haven't had any experience in walnuts.

Mr. Littlepage: I would like to ask Mr. Roper if he knows of any examples where selection of fine varieties of seed has not resulted in getting a more productive variety of the plant which he was producing?

Mr. Roper: Only one, and that wasn't in a tree.

President Morris: In regard to coming true to type, I think records have been made of many thousands of pecans, and I don't know of any instance where the progeny resembled the parent closely.

Mr. Pomeroy: Maybe someone could explain one of my failures a few years ago in planting some Persian walnuts. I went to another tree in western New York, and got a peck or more. They were planted the same day, in the same ground, and all came up. Those I got from another tree resembled a hill of beans, and stayed that way for three years. Why wouldn't those grow? In soil three feet from those, there were trees growing. Those nuts never did make trees. The nuts were of good size.

Colonel Van Duzee: As a practical nurseryman, I wouldn't think of planting nuts from a tree that I didn't know individually. We have had very much better success with nursery stock where we have chosen as seed medium sized nuts from vigorous trees with which we were acquainted. In the case of Mr. Pomeroy, I don't think there is any question but that the history of his tree would account for the failure. In other words, his nursery stock was undoubtedly from the results of years of slow growth on the part of the original tree, or unfavorable conditions of some kind. I don't quite agree with Professor Craig on the question of the influence of stock, because I believe it is really a very important point.

President Morris: We are not here to agree upon anything.

Colonel Van Duzee: I can't speak from the scientific standpoint, but I am quite sure that in the nursery business I shouldn't care to overlook that influence.

President Morris: When men agree, it means we are on stale old ground which has been thrashed over.

THURSDAY AFTERNOON, DECEMBER 14, 1911.

President Morris: The meeting is called to order. The first paper this afternoon will be that by Mr. J. Franklin Collins of the United States Department of Agriculture, on the chestnut bark disease.

THE CHESTNUT BARK DISEASE.

J. FRANKLIN COLLINS, Washington, D. C.

I presume some of you know as much about certain features of this chestnut disease as I do myself; for I have only worked over certain sides of the whole question. I also presume that you are all acquainted with the fact that this disease, which is known as chestnut blight or the chestnut bark disease, is without doubt the most serious disease of any forest tree which we have had in this country at any time, that is, so far as its inroads at present appear to suggest.

I want to call your attention to certain general historical facts in connection with the disease, facts which are familiar to some of you, but unfamiliar possibly to others. The Forester of the Bronx Zoological Park, Dr. Merkel, discovered in the fall of 1904, or had his attention particularly called in 1904 to the fact, that a good many chestnut trees were dying in his vicinity, a number sufficient to have attracted especial attention. He looked at the matter carefully, and decided that there was a definite disease on these trees. He handed specimens over to Doctor Murrill of the New York Botanical Garden; who worked out the disease, and decided that it was a new fungus which was causing the trouble. He named it _Diaporthe parasitica_, the name under which it is generally known today, although there is some question as to whether that is the one which should be applied to it. This, you remember, was in 1904--in the fall.

The first publication which appeared on the disease was in 1906, as I recall it. The publication which then appeared was Doctor Murrill's upon his investigations. The disease has spread very rapidly since then, so that today we know the disease in a general area indicated by the red color on this map. The green area indicates in a general way the natural distribution of the common chestnut. Since 1904 investigations upon the geographical range of the disease have been carried on so far as to show that the disease is now known over approximately the area indicated in red on that map. The northern limits of the disease are perhaps in New York State. Further east, it is known as far north as northern Massachusetts, mainly in the western part, and it is also known in Boston. There have been two or three cases of the disease found in the Arnold Arboretum. On the west, we have two cases in West Virginia, and the most southern station which I know of is in Bedford County, Virginia. But those are isolated stations beyond the area which is indicated here. I shall have a little more to say in regard to the distribution.

Before speaking of that, I want to call your attention to a few points in regard to fungi in general, points of common knowledge to all who have studied fungi or mycology. A fungus is a kind of plant which does not, on account of the absence of the green coloring matter, manufacture its own food. It is a plant which has, in other words, no green foliage, and as it has no green foliage, it must obtain its organic or elaborated food from some other source. The fungi have very aptly been termed the tramps of the vegetable kingdom, that is, they live on food prepared by somebody else. They can take certain organic substances and change them apparently into other organic matter which can be used by the plant. In the case of this chestnut fungus, we have a fairly typical fungus in certain respects. We have a vegetative stage of the fungus which is nothing more or less than a lot of threadlike structures penetrating the bark of the chestnut, the inner bark or the middle bark, and there drawing the organic matter from the bark of the chestnut and appropriating it to its own use. Fungi, like practically all other plants, have two stages of existence, one the vegetative or growing stage, the other the reproductive stage. Sooner or later the fungus will produce the fruiting bodies, after it has obtained a sufficient amount of food to justify the formation of these more highly organized structures. In the case of the fruiting body of the chestnut fungus, we have very small, pinhead-like structures, which come out to the surface of the bark, the vegetative portion developing through the interior of the bark. On smooth bark we find that these fruiting pustules are apt to appear all over the surface. With bark that is sufficiently old to have ridges and crevices, we find these fruiting bodies only in the crevices.

These fruiting pustules which you will see on this bark are the structures which produce the reproductive bodies, these latter being known as the spores. There are two types of spores which are produced by this fungus. One is the type which is commonly spoken of as the summer spore, the other the type which is spoken of as the winter spore. The winter spore is known from the point of view of the mycologist as the perfect stage of the fungus, that is, it is the more characteristic of this particular fungus. If we should make a cross section of the bark, we should find that the vegetative stage is running through the middle bark, and commonly the inner bark, sometimes in one place only, sometimes in the other only, sometimes in both. This vegetative stage later sends up in various ways a mass of tissue which results in the formation of pustules. These appear on the surface, sometimes more or less regularly rounded, sometimes rather irregular. In the case of the summer spore stage, we have inside the pustules a mass of tissue which is formed into spores. The interior of the spore mass, or at least portions of it, is somewhat mucilaginous, so that when moisture is applied a swelling of the interior mass is produced at a certain stage and something has to break. As a result, we have a mucilaginous mass pressed out through the break in the shape of a twisted thread, much the same as if you take a collapsible tube of paste and pinch it.

Now, one of those summer spore threads may contain anywhere from one to five million spores. I have tried to estimate the number in a thread of this sort which was about an eighth of an inch long, and by taking a certain portion of that thread, mounting it in a drop of water, and then counting over a certain measured area under the microscope, I have estimated, by multiplying, that there were 2,400,000 spores in that one thread. So you can imagine how many of these spores may be produced by a single diseased area which has produced perhaps four or five hundred of those pustules, each pustule containing anywhere from one to twenty threads. Each one of those spores may develop a new diseased area, provided it is transported to a fresh break in the bark of a chestnut tree. Fortunately, only a very small fraction of one per cent ever reaches the proper place for growth.

This last is what I alluded to as the summer spore stage. There is a winter spore stage, or technically, the ascospore stage, which comes, as a rule, later in the development of the fungus. In this same pustule, later in the season, certain sacs are formed. These have long necks which extend to the top of the pustule. These sacs are sufficiently large to be seen with the naked eye. They are dark colored. Inside these, we have a lot of smaller transparent sacs or cases in each of which we get eight spores, sometimes in one row, sometimes in two rows. Each spore can propagate the fungus.

We have, then, two types of spores, either one of which can reproduce the fungus under suitable conditions. There is still another way by which the disease may be kept going. The vegetative stage can survive the winter and continue growing the following year.

I will say right here that I am planning to give you merely an outline of this disease, and have time afterwards for questions which I think in a meeting of this sort are one of the most productive sources of information.

In regard to the rapidity of spread of this disease, I will merely call your attention to two cases as illustrations, or to certain facts, rather. One is that the disease, so far as our attention has been directed to it, has developed over the area indicated on the map since the fall of 1904. Another case is one which has occurred in Rhode Island, where I have had a chance to watch its development a little more closely than in other places, that is, more constantly. In the fall of 1908, after I had made over thirty excursions around Rhode Island, I was unable to find a single trace of this disease, and no one else was able to find a single case of the disease in Rhode Island. In May, 1909, I happened to be about five miles west of the city of Providence, and I found two or three cases, all in one rather restricted spot. Later, it was discovered a little farther south, and soon, a little to the north, so that at the end of the season of 1909 we knew of about ten cases in Rhode Island. At the end of 1910, a season in which very few trips were made with the special object of surveying for the disease, we had more than doubled the number of infections found. That led to putting someone into the field in 1910 to make a survey of Rhode Island. A man was also put into the state of Massachusetts for the same purpose. Mr. Rankin, in cooperation with the United States Department of Agriculture, made a survey of New York State, which has resulted in this map. A man was put into Pennsylvania and one into Maryland for the same purpose. As a result of the survey in Rhode Island, where at the end of 1910 we knew of less than fifty cases at the outside, we now know of very nearly 4000 cases. It has been much the same story in Massachusetts. At the beginning of this year, there were four towns in which the disease was known; now there are seventy-one. At present in Connecticut, the disease is known in one hundred thirty-two towns of the one hundred sixty-eight in the state, and the southwestern part of Connecticut is very badly infected, just as badly as the adjoining portions of New York.[A]

[Footnote A: Since this statement was made the disease has been definitely reported in approximately 164 towns in Conn. [J. F. C]]

So much for illustrations of the rapidity with which the disease develops. I am not going to say at this time anything special about the origin of the disease, simply because we haven't yet decided what was the probable origin. I will merely say there are some different theories in regard to the origin. One is that it was imported from the Orient, another, that it is a saprophyte, a fungus which has lived normally upon dead organic matter, but which has taken on the parasitic form, which develops on living organisms.

In connection with any disease of this sort, one naturally inquires, how are we going to recognize this disease? This past summer Pennsylvania has put into the field thirty or more men who have been trained to recognize this disease, with the idea of locating the infections in Pennsylvania. As perhaps all of you know, the legislature of Pennsylvania has passed a law relating to this particular disease, and has appropriated $275,000 to see if the disease can be controlled. Their idea is that they have perhaps fifty million dollars' worth of chestnuts, and if $275,000 can show whether or not this disease can be controlled, it is economy to try it.

So far as Pennsylvania is concerned, it means possibly the saving of the chestnuts in the middle and western parts of the state; but it also means that if they can check it there, it is likely to save the great area of chestnut growth along the southern Appalachians. I don't want to make any prophecy as to how that experiment is likely to come out, but, however it comes out, it will be a very great object lesson as to what can be done on a large scale with a disease of this sort.

One of the first things which had to be considered in Pennsylvania was to train a number of men to recognize the disease, so as to go over the country and locate the diseased spots. The method of recognizing the disease I will briefly outline. Of course, over a large country, many hundreds of square miles, it is a long, and laborious operation to look over every tree. It is perhaps impossible without a very much larger force than $275,000 could put into the field. But there are certain clues to the location of the disease which can be seen a long distance, a quarter of a mile, at any rate. The means of recognition is by what I commonly call danger signals. This fungus, when growing through the bark, starts from the common point of infection and grows in all directions, up the stem, down the stem, and around the stem. Wherever this vegetative stage, technically known as mycelium, penetrates, the bark is killed; and of course, you all know what that means. When this has succeeded in reaching around a twig, branch, or trunk, everything beyond that girdled area dies, not immediately, perhaps, but sooner or later it dies; and it dies in such a way that the leaves change color during the summer. The first obvious change which can be noted is a slight wilting of the leaf; then the leaf assumes a pale green color, and from the pale green it takes on a yellow stage; from this a reddish yellow stage, and then a brown, till the leaf is the ordinary dark dull brown of the dead leaves. This coloration which takes place is conspicuous. There is your guide, your danger signal. If the disease has worked very long, half a season, in one locality, you are almost sure of getting some of these danger signals. Where one is present, you can go and look up the cause of that danger signal. It may be a broken twig, but the point is to find out if it is this disease which has caused the danger signal. We start by looking at the danger signal, then at the base of the dead area. If we find here some of the reddish pustules which have been shown on this bark we are quite sure that the disease is present. Then by cutting into the bark a little, instead of the normal buff or yellowish tint of the fresh clean bark, we get, when the disease is present, a rather mottled effect, varying from a brownish to lighter or even darker. There is a peculiar fan-like effect to this mycelium which penetrates the bark, so that by shaving off the surface of the bark, you get this mottled appearance, which gives you another means of identifying the disease. So we look for the danger signals, and then look for the meaning of the danger signals. If we find those two things, the pustules and the mottled mycelium, we can very safely say that this disease is present.

There are a few fungi which closely resemble this chestnut disease in general appearance, but they are not very common, and are not confused with the disease, as a rule, when you get the lens on them.