Chapter III: Front Matter (3)

The pecans at Burlington are growing under similar conditions to those at Clinton, but they are much more numerous, there being thousands of them, some being larger than any seen at Clinton. Four trees, including the Marquardt, have been discovered and brought to the attention of the association by Mr. Ed. G. Marquardt and Mr. John H. Witte of Burlington. Cuts of these nuts, natural size, are shown opposite page 48. The Marquardt is being propagated by me and the other three varieties by Snyder Bros., Center Point, Iowa.

From the appearance of the leaves, buds and habit of growth of the Marquardt pecan, it seemed to me that the tree had hickory blood in it, although the nut did not suggest it; and I intended to look into this matter fully, on a trip to Iowa the past fall, but finding I could not go, I gave Mr. Bixby samples of the nuts, leaves and twigs and told him what I expected, and he had this in mind during his trip. He never found young pecan trees growing in the woods but did find them growing in large numbers on the levees and on the edges of cultivated fields. A careful examination showed a very considerable variation in leaf, bud and habit of growth and there seemed little question but that there were among them many hybrids between the pecan and the big bottom shellbark, _Carya laciniosa_, which is found growing on the bottom lands and the islands along with the pecan. As a matter of fact, two of the four Iowa pecans selected for propagation, the Burlington and the Greenbay, show unmistakable evidence of hybrid parentage in the nut, in the leaves and buds. The Marquardt gives no hint of such parentage in the nut, but the leaves and buds do suggest that it has hickory blood in its make up, and it is believed that this is so. The Witte is seemingly a pure pecan.

There has recently been much done near Burlington in reclaiming valuable, cultivatable lands from the river which formerly overflowed them each year so that people were afraid to plant crops and they were therefore abandoned to the forests. Levees have recently been built to keep the water off these lands in time of high water. Drainage ditches have been made behind them and pumping plants put in to pump the water out of them. The cost of these improvements, which has given to cultivation much very fertile land, has been assessed on the owners of the lands benefited, as is also the upkeep expense. Many owners had not the money to pay the assessments and have sold the land to those who are clearing off the timber. This means the clearing of thousands of acres of bottom land and the pecan is one of the principle trees on these bottom lands. This condition makes it necessary to locate and propagate at once, the best and most promising of these Iowa pecans and hybrids and observe their behavior afterwards in the young trees, instead of depending on the watching of the behavior of the original trees as has been the case in Indiana.

I feel reluctant to close this address without mentioning the good work done by Secretaries Deming and Bixby and other members of this Association in searching for varieties of nuts that may be superior to what we already have. Those of us who are propagating these trees, while we may feel the inspiration that comes from doing a work that benefits mankind, nevertheless, we hope and expect to make dollars and cents out of growing these trees, while this is not the case with some of the members of this Association who are not nurserymen and who do not expect to enter this field.

Dr. Deming, former Secretary of this Association, did much good work and secured some fine nuts worthy of propagation, through advertising and the offering of premiums, and Mr. Bixby, who very kindly took up this work when Dr. Deming was called to the colors, has been active and is doing a great work for northern nut culture.

PRESIDENT REED: We will now have a grafting demonstration by Mr. Jones.

Mr. Jones had brought with him specimens of stock, scions and all the materials and tools needed for the demonstration, and performed the various operations of grafting and budding before the audience.

MR. JONES: We often use scions half or three-fourths of an inch in diameter, for grafting, but they are rather hard to get. In top working, we generally take limbs two to four inches in diameter, cut them off, and split the bark. The nut grafting must all be done late when the sap is up in the trees. Cut the scions all on one side. Split the bark, slip in the scion, tie up and wax the whole scion over with grafting wax, put it on hot and seal it up tight. Sometimes for winter protection of the English walnut as far north as Michigan your tip might kill back because it grows so very fast and is sappy. I have never

had trees kill in that way, but I do have many people write me that they have trees killed in that way. In nursery grafting, we usually use just the cleft method. You should cut the cleft on one side and don't split it, but keep it smooth all the way through.

PRESIDENT REED: You get better results, Mr. Jones, from waxing the entire scion?

MR. JONES: Yes, we get better results that way. In the South we have no success at all that way; we have to cover them with sacks.

VOICE: About what degree of heat is best for the wax?

MR. JONES: Don't have it too hot and it can't burn. You can tell that by the wax smoking.

PRESIDENT REED: As long as the wax does not smoke, it is pretty safe.

MR. JONES: This illustrates what we call a side graft. Put the scion in the side and leave the top on. You can also do it in bark grafting. Cut your bark, split it, and stick your scion straight down as it is here.

VOICE: How do you apply the hot wax?

MR. JONES: With a swab or brush. We use a carbon heater and that makes it about the right temperature.

VOICE: How large black walnut trees could be top worked to English walnuts?

MR. JONES: You can work almost any sized tree, but it is quite a job in the large tree. Take a tree larger than six inches in diameter, or eight, and it would not be very satisfactory. In cutting the scions be careful to make a straight surface on the cut bevel. To do that the knife should be held at an angle lengthwise to the scion. In our grafting in the South we leave the scion dry and cover it with a bag. That was in Florida.

DR. MORRIS: That is a very interesting question about the limits of our using the method of covering the scion and all with the wax. I shall speak of that in my own grafting demonstration which is short. I got the point from Mr. Jones, and Mr. Jones tells me he got it from Mr. Riehl. They use black wax and hard, strong wax.

MR. JONES: Mr. Riehl uses a liquid wax, resin and beeswax without the coloring matter. We use the coloring matter to toughen the wax.

DR. MORRIS: Still, that is amber. Amber will cut out light, and it seems to me that it is a matter of a good deal of consequence, the black or amber wax covering the graft completely, buds and all, wound, scion, stock. It succeeds in the North, succeeds better than any other method in grafting, and yet in the South it does not succeed. It is possible that as you get further south the longer sun, the hotter sun scalds the cambium layer of bark beneath when it would not do so in the North. That is at least worth thinking about. In my own work during the past year I have used transparent paraffin alone, nothing else. I have tried different kinds of paraffin, the Parowax, the common one that the women put up preserves with is the one that will stay on best, will not crack and is perfectly transparent, allowing the light of the sun to act upon the chlorophyl, in the bark and the bud and intensify the activity of that part of the plant that depends upon light transformation by means of chlorophyl. I am very much interested to know if this will not succeed in the South. Paraffin would not attract the heat of the sun, and it is possible that this will allow us to carry the method of Mr. Jones, the best method to date, still farther south.

MR. JONES: I think, Doctor, it is a matter of heat, because in the shade you can graft them almost any way. Do you cover the scion with paraffin or only the union?

DR. MORRIS: I cover the entire thing with paraffin, scions, buds and all including the wrapping. I don't leave anything exposed to the air. There are several principles involved there. In the first place you have the effect of light upon chlorophyl which is important; in the second place, the melted paraffin fills all interstices in which sap would collect and ferment. If those interstices are filled with melted paraffin, sap will not collect there and ferment. The microbes of bacterial and fungus origin, that prevent union and break down the products of repair that are thrown out for the purpose of repair, can not do it if they can not collect in quantity, and the paraffin fills the space in which they would collect in quantity; so that does away with another one of the dangers. In the third place, you have the same sap tension maintained in the scion as in the stock. The difference between the negative and positive pressures, day and night, is very great in spring time, and as the sap responds between day and night in the stock, it puts a strain upon the scion. The scion can not follow the stock with its sap movement ordinarily. But if scion and stock are covered completely with paraffin, the tension remains the same, so that you do away with the shock of varying negative and positive pressures. That is an important point, it seems to me, in principle in the matter of using the paraffin. Another point is this. You prevent evaporation from scion that goes on ordinarily through the little breathing lenticels, the little apertures between the cells of the bark which allow moisture to escape as well as to enter. One would naturally believe the paraffin would fill these and smother the scion, and I presume it is that fear which has prevented the world from trying this for the past ten thousand years, because they were skilful grafters in Egypt, both in the tree world and the financial world, in the days of Hammurabi there were skilful grafters in both worlds two or three thousand years before Christ. I suppose that fear of closing the breathing apertures in the stock has prevented people from adopting this method; but it is not justified, because those bold, brave nurserymen who are not afraid to smother a scion find that all the scions live. It is a venture into the unknown, that dramatic book, in the way of dramatically constructive progress. Another point: When you protect your graft in the ordinary way with ordinary wrapping, ordinary wax, the scion becomes timid, the stock becomes timid. It is not quite sure of itself in many cases, and when it is not sure of itself, when it has a fear, what does it do? It resorts to the protection method. What is the first? Suberization, cork layer formation. So the frightened stock throws cork cells over its cut surface between that and the graft, and the suberization goes on as a result of fear on the part of the timid stock. When you have taken away the fear by covering the whole area with melted paraffin and it feels safe, then suberization does not go on in this way, your stock is not frightened, you have not a scared tree at all, and it will go on kindly and gently as a Jersey heifer to do its work.

PRESIDENT REED: I would like to ask Dr. Morris about that myself. I am very much interested in the line of grafting, as we graft 50,000 to 100,000 every spring, using this same method. I feel as Mr. Jones does, that the losses from grafting are largely due to heat and the fermentation of sap. We find perhaps, that the first week of grafting in cherry, we can almost invariably secure a fairly good stand. Following that it tapers as the warmth and air increase, although the scions are kept in cold storage, perfectly dormant, the sap is coming up, and the increased rays of the sun--we get a very small percentage, and it seems to become less every day, and we have always used the dark wax. While I have been using paraffin wax a good deal of the time, I put lampblack in it for coloring.

DR. MORRIS: I have until this year. In order to get Mr. Jones' points, I tried to work out the philosophy of the subject and see what values there are, what meanings in the methods which led to his success. Then following that line of investigation, I stopped into another line of observation, and arrived at the transparent paraffin method, so that this is the first year in which I have tried it, but the results are perfectly remarkable. I have only done it for a year, but you will see 100% of catches on almost everything, hickories, walnuts, hazels. I must tell you of one very remarkable incident. Mrs. Morris had some dwarf trees set out on the slope of the lawn, dwarf pear trees. One of my men cut one of them off with a lawn mower the latter part of August. The top kicked around under foot for three or four days, wilted in the sun. We were walking past it along in August. I think Mr. Bixby said, "Why don't you try grafting on that kind of material?" I said, "I will, blessed if I don't." So I cut three pear scions from this wilted top that had been cut by the lawnmower in August, and I put them on a scrub pear tree under the fence near the house. And I tried this paraffin method, and in about six days one of them started out a shoot, and I said to one of my men, "We will transplant this. This is no place for it." I meant in the spring, or in a year or so. He transplanted it the next day. And it grew I think about half an inch after that, made good wood to last through the winter. So I don't know what the limitations of this paraffin method are. But that is a thing I would hardly dare tell about unless there were men here in this room who had seen it. That little pear top, cut off by mistake, kicked about under foot a few days in August, no sort of scion that any one would ever think of using as a graft, put it in as a joke, and with the further abuse of being transplanted; but it started growth, and now it is going to be a good pear tree.

MR. JONES: The kicking around only made it good for grafting.

PRESIDENT REED: Perhaps it ripened up to a certain extent by that drying out, like it would in the fall.

DR. MORRIS: Maybe, but I have never heard of horticulturists propagating trees in that way and transplanting them in the same year, and having the new wood from the graft harden for the winter.

MR. JONES: Mr. Reed spoke of grafting a cherry. You cut the top off didn't you?

PRESIDENT REED: Yes.

MR. JONES: We graft filberts by leaving the top on and cut the graft in on the side and wax it over. We leave it there two weeks, maybe, and cut it off, and we get perfect stands that way, and you would on the cherry.

PRESIDENT REED: We use the side grafting, but we cut the top off.

MR. VOLLERTSEN: I would like to ask Dr. Morris with regard to the stock. Don't you think the fact that that tree was moved at the time it was, so soon after grafting, had something to do with the retarding of the sap and causing the tree to mature the wood it did in place of making more growth?

DR. MORRIS: That might be. All of the expert horticultural opinions brought to bear on this are valuable. Every suggestion that has been made has had a meaning. It requires explanation.

PRESIDENT REED: If there is nothing further along that line, we have with us Mr. Conrad Vollertsen, of Rochester, who has been asked to prepare a paper; and we would like to hear from him. He is an expert in the filbert, and I believe can give us some valuable information. (Applause).

HAZEL NUTS AND FILBERTS

CONRAD VOLLERTSEN, ROCHESTER, N. Y.

Mr. President, Ladies and Gentlemen of this Convention: I have been approached by a member of the Northern Nut Growers' Association to prepare a paper to be read at this convention on the growing, cultivating, and propagating of the European hazel, together with such other topics on the subject, as would be of interest to the members of this association, particularly my experience and observations during the last three or four seasons in my hazel orchard and nursery.

Now, Ladies and Gentlemen, I am not a public speaker nor a public writer; my business is nursery and garden work; I can use spade and pick more freely than pen and ink, and, therefore, fear that I am not the right party called upon, knowing as I do, that we have members in this association far more capable and experienced, and who possess more knowledge about the European hazel than ever I had. Nevertheless as the growing and planting of the European hazel in the eastern and middle states of our country so far, both for ornamental or commercial purposes, has been more or less experimental, I think all practical information on the subject should be welcomed, and therefore I have consented to prepare this paper and hope it will be accepted for what it stands.

A number of years ago, after leaving school, I entered a large nursery and garden establishment in Germany, as an apprentice boy, to learn the garden business, to become a gardener and horticulturist, to learn how to raise trees and other plants, to learn how to graft, to prune and cultivate, and, in general, to take care of all kinds of growing plants. One of the first duties bestowed upon me in my new place was the charge of a large plot of young hazel or filbert plants. To prune or graft them? Not at all. At that time I did not know anything about such skilled labor. I was merely told to weed and hoe them and to keep them clean. It was not just very elegant work, but, ladies and gentlemen, I enjoyed very much indeed, every minute so employed among those young filbert bushes. I became really attached to them and knew practically every plant in the plot, and almost believe they knew me, too.

Now what was the reason for this immense pleasure I found in working among those plants? Was it perhaps from the commercial or financial point of view, the future income from them for fruit or when the plants reached a saleable age? Not at all. I was then too much of a boy and did not comprehend such a thing as that. It was merely the fond and pleasant recollection of my childhood, of my boyhood, when, together with other children, in the proper season, we went hunting for the common hazel nuts, the _Corylus avellana_, as the gathering of these nuts is one of the greatest pleasures of the German country child, and to roam through fields and woods in late summer in those beautiful September days, when the foliage of trees and bushes begin to color, when the birds of the garden, field and forest begin to assemble for future migration, when goldenrod, asters and other field flowers are reaching their greatest beauty, then, ladies and gentlemen, the hazelnut has reached maturity. The nut itself is a very beautiful brown color, the outer bark a golden yellow, the leaves of the plants slightly colored with bronze, pink or yellow, a most beautiful combination, a pleasure to look upon, and a sight never to be forgotten. Whoever has had an opportunity to see and admire a well fruited hazel plant, at the time of maturity, will agree with me that it is a thing of beauty, not only during the fruit bearing season, but in fact throughout the whole winter, with the handsome staminate flowers or catkins appearing very abundantly in early fall, and remaining throughout the winter, until late spring. Of all these pleasures, these beautiful sights, etc., of which a vivid and fond recollection caused all the pleasures in cultivating the above mentioned hazel lot, we need not be deprived in our otherwise so richly blest country. It is true that, at the present time, we have no American native hazel, that can fully compete with the better European varieties, but we hope that in time not far off, through scientific hybridization, such will be produced. For the time being, we have some very fine European varieties as a substitute, which for years have stood the test very well, and should be planted wherever a place can be spared for a few of them, and great pleasure and enjoyment will be the result. So much for the pleasure of raising hazel nuts. I have related the foregoing merely to show the lasting pleasure and enjoyments derived from the planting, cultivating and gathering of a few European hazel nuts.

But to raise hazel nuts for the pleasure of it only, would be a very poor business proposition, and certainly not a paying one. What we should do is to raise them in large quantities, for commercial purposes, but here it seems to me the question should be asked: Have we had experience enough as to recommend the planting of them in the middle and eastern states for commercial purposes? In other words, is it worth while to plant them with that point in view? Now, gentlemen, I do not suppose that any one of us, at the present time, would be fully capable or prepared to answer this question intelligently or positively, as the planting of the hazel, for commercial purposes, has not been tried long enough, at least not in the eastern or middle states, to warrant a positive opinion on the subject. A great deal depends upon the variety planted, also the location where the planting is done. Much observation and experimenting is still required.

I have growing on my ground in western New York, near Rochester, several hundred trees or bushes, 6 to 8 years old, about 20 varieties, most of them German varieties, a few from France, and a few from England. They have been bearing nuts the last four seasons, and all have reached maturity perfectly. The smaller and medium sized nuts appeared to bear a little better than the larger varieties. The varieties received from France have, so far, not done well with me, as the German varieties. They are poor bearers. In the fall of 1917, I gathered from each 5 to 6 year old tree, of the German variety, about a pound and a quarter of the medium sized nuts, while hardly a pound from the larger fruited varieties (same sized plants) ripened well. I was then under the impression that the hazel not only could but should be planted in large numbers for commercial purpose. In the fall of 1918 my crop of nuts was very much less, and I had expected even a better harvest than in 1917, which certainly was discouraging to me. The plants themselves were growing beautifully, but most of the staminate blossoms or catkins were frozen, and, consequently, very little pollenizing was accomplished, and very little fruit the result. Such and possibly other occurrences, from time to time we may expect and look for, and should be ready to investigate thoroughly, before we can advocate or recommend the planting of the hazel extensively.

It really seems strange that while the hazel generally is at home in the northern latitudes, it should partly freeze when the thermometer reaches say about 12 to 18 degrees below zero, and, as I had never noticed that before, it then occurred to me that possibly another reason could be found, why so many of the catkins were frozen.

Through my investigation in the spring of 1918, I have come to the conclusion that the unusually wet season in our vicinity of western New York throughout 1917 caused the hazel plants to grow until the real cold weather was upon them, which gave the wood a very poor chance to ripen, particularly the terminal buds, where a great many of the catkins had formed, and caused not only them to freeze but also a certain part of the wood. Only the lower and more protected catkins came through the winter alright and caused what little pollenizing was done, hence the very light harvest in the fall of 1918.

Should the results of my investigation prove true, and the continuance of the wet weather prove the main cause of freezing so many catkins, then it seems to me there is nothing to be alarmed about, and the planting of the European hazel, at least in this vicinity, for commercial purposes could be conscientiously recommended, and should be done, the sooner the better. We do not expect our apple or pear orchards to bear an abundant crop every year, and we should not expect it of our hazel orchards. Something will occasionally happen to them as well as to other crops, otherwise we run no risk whatever.

My trees or bushes, several hundred in number, planted in 1912 and later, have stood all kinds of weather, extreme cold, very hot, continuous wet, and still are growing most beautifully at the present time. They gave a very satisfactory crop of nuts this last fall, 1919, in spite of severe freezing weather on April 25th and 26th when the mercury dropped to 12 to 15 degrees, and all hazel bushes in full bloom. At the present time the prospect for a good crop of nuts next season is certainly very bright.

Neither fungus, blight, or other diseases of any kind, or troublesome insects have so far been detected. In planting the hazel for commercial purposes, I should recommend 12 feet distance between the plants each way, as they require abundant sun and air. At the same time, there is an opportunity to use the land between the rows for several years to come, as low growing crops like potatoes, strawberries, beans, beets, carrots, etc., could be grown there to great advantage, and the cultivation of these crops would be amply sufficient for the hazel plants.

Now the selection of varieties to be planted for the commercial hazel orchard is a very important part of the undertaking, and should be well considered. To plant several varieties is absolutely necessary on account of pollenizing, as staminate and pistillate flowers, though on the same plant, do not always appear together in proper condition on all plants; in fact it has been proven in my orchard that sometimes plants bring forth a great many pistillate blossoms and not a single staminate one on them, and still a good crop of nuts were grown on them. Here the pollination must have taken place with the pollen from other nearby plants conveyed to them by wind or insects. One particular plant of the zellernut type grown in one of my city lots during the last season was very well filled with pistillate blossoms and not one catkin on it, and still it ripened a fairly good crop of perfect nuts, where the nearest plants filled with staminate blossoms was at least 30 feet from it. Here it is shown and proven that a number of varieties is a necessity.

But what varieties we shall choose, will undoubtedly be an open question for some time to come, and, no doubt, a great deal of experimental work will have to be done to finally select the right varieties for the different localities, the variation of temperature and location has very much to do with the proper selection of varieties. I have among my varieties some I could recommend and again others that are not at all satisfactory, at least not so far, and it requires more close observation before the very best of them can be picked out or selected.

Our next operation in the hazel will be the pruning. Here I should say above all things: "_Keep the suckers away._" Hazel bushes are naturally inclined to produce a great many suckers, which should be thoroughly removed as soon as they appear; it will stop when the plants grow older. Besides the suckers, all weak and unnecessary wood should be removed entirely, not cut back. Our aim should be to try and get as near as possible low standard trees, with trunk say 10 to 15 inches high and the tree itself not to exceed 15 to 18 feet in height with the center kept open all the time. To accomplish this, I should suggest the removing of all crowding limbs from the center, regardless of their being fruit-bearing limbs, which to determine is mostly guess-work at the best. In order to keep the plants within 15 to 18 feet in height, the terminal shoots also should be removed or reduced as the case may be, beginning at the time of planting until the desired height is reached. After that, one or more of the old limbs may from time to time be removed, as there always will be enough young branches to take their places. Such pruning in my orchard, so far, has proved sufficient, as blight has never made its appearance in my nursery.

I will not be able to say much about blight. I have known trees in our city, 4 or 5 varieties, for more than 30 years, bearing more or less fruit year after year, and have never noticed any blight or anything wrong with them. Should blight appear, I should remove all affected limbs to the sound and healthy wood, as we would do to our pear and quince trees when blight appears among them. I do not believe that properly treated hazel bushes will ever suffer much from blight, at least not in our vicinity. Neither do I believe that any more pruning than I have outlined is required or necessary to our hazel plants.

The next subject about which I wish to say a few words is the propagation of hazel plants. There seems to be quite a difference of opinion as to the mode of propagating them; some advocate grafting, others layering, again others from suckers only. Grafting I believe myself, will produce a finer plant and the operation of doing so seems quite successful, but a great many varieties produce so many suckers that the graft is liable to be choked or crowded out if not constantly watched, and it should not be expected of the average person to know the difference between the graft and the wild shoot, and consequently, in a comparative short time, he would have a wild or common hazel. For that reason grafted plants should not be used for the trade until our people get better acquainted with hazel plants. I, therefore, should recommend layering, thereby having the plants on their own roots, which would prove more satisfactory everywhere. That grafted plants bear fruit sooner than layers, does not always hold good; it may be so with some varieties, but not with all of them. I have some three year old grafted plants and no fruit as yet, where I had plenty of layers in the nursery rows two years old well fruited.

It is true that plants grafted on seedlings of the _Corylus avellana_ will not produce as many suckers, as plants grafted on layers of the avellana type, but they will produce enough to confuse the average person, as the foliage of some varieties are so nearly alike, that it actually requires an expert to tell the difference. I, therefore, under the existing circumstances, should advise the propagating of hazel plants by layers only, until our people get better acquainted with the hazel proposition in general. Why propagation by suckers only should be preferred by some people, I fail to see, as they are practically the same as layers, plants on their own roots from a parent plant, only that layers are produced a little more scientifically and suckers more naturally; otherwise they are identically the same thing.

When I referred to propagating, I should perhaps have mentioned the growing of hazel plants from seeds, that is from the nut, but I did not think it necessary. I will, however, say that plants raised from seed should never be planted for fruit bearing unless they are grafted or budded, as it has been fully and positively proven that plants raised from seed, even if the very finest nuts of our European hybrids are planted, will not produce nuts as good as those planted, but will almost invariably go back to the original type, the _Corylus avellana_. It is alright to raise plants from seeds for the sake of getting stock to graft or bud on, but, as to variety, the seedlings are unreliable.

Before coming to a close, I would like to say a few words about the fertilizing of the ground for hazel orchards and what experience I have had in this matter, as I believe this would be of interest to all. It is a well-known fact that hazel plants grow well and will thrive in almost any kind of soil, as long as it is not too wet or too heavy, but from time to time a little manure worked in is very beneficial both to old and young plants, but care and judgment should be exercised, so as not to overdo it. I have growing in one of my city lots with very fertile soil, several bearing hazel plants, 7 to 8 years old, different varieties. These plants grow so immensely that it plainly shows, they are growing at the expense of the fruit, not only that the quantity of nuts gathered from a plant there is considerably less than of same sized plants grown on ordinary farmland, but the quality also is very much below. My best nuts are all grown on ordinary farmland and the greatest quantity has always been obtained from the farm where only very little fertilizing or manuring had been done. For the growing of young plants for commercial purposes, for the trade, I should recommend liberal manuring at all times. (Applause.)

QUESTION: Is the hazel a long lived tree?

MR. VOLLERTSEN: I have known trees for almost forty years that are bearing good fruit year after year, although not always a good crop. They don't seem to grow so rapidly at that age as when younger.

DR. MORRIS: Hazels seem to graft pretty well on each other. I think the tree hazel is going to be our most successful stock for grafting. However, I have grafted on the _Corylus avellana_. The tree hazel does not put out any suckers.

QUESTION: Does the hazel find its way into the market commercially?

MR. VOLLERTSEN: I would almost think so. I have had lots of inquiries for them from storekeepers. It seems to me there are a great many imported around here. Our American hazels are not so very good. There may be here and there a fairly good one, but I have not found any really good ones worth propagating. I think if we would do more scientific work we could get very good nuts. There is no question that they are perfectly hardy and will stand almost any climate.

MR. JONES: Some of your varieties are hybrids aren't they?

MR. VOLLERTSEN: They are all hybrids. I have a few of the real, original _avellana_ type I think got there by accident.

PRESIDENT REED: I believe the next paper is one the secretary has from Mr. A. H. Graves.

DISEASE RESISTANCE IN THE AMERICAN CHESTNUT[1]

ARTHUR H. GRAVES

(Read by the Secretary)

Your secretary, Mr. Bixby, has asked me to tell you about the native chestnut trees in the vicinity of New York City which I have found to be resistant to the destructive bark disease. I commenced the search for such trees in the summer of 1918, at the suggestion of Dr. Haven Metcalf, of the laboratory of Forest Pathology, Bureau of Plant Industry. During the campaign in Pennsylvania against the bark disease, scouts had been on the lookout for immune or resistant trees, but without result. As far as I am aware, no systematic organized search had been made for such individuals.

It was our plan to commence the search in the region of New York City, because this area is probably the oldest center of infection in the United States. Apparently this is the port of entry where the undesirable immigrants (Japanese or Chinese chestnuts) passed through quarantine and were allowed to disembark carrying their terrible scourge with them unnoticed. According to Metcalf and Collins,[2] this was probably as early as 1893. This was why we selected this area to begin on, for here the disease has had a longer opportunity to run its course than anywhere else, and, consequently, has had ample time (more than a quarter of a century) to call out the non-resistant trees. Those remaining, if any could be found, might be suspected, _a priori_, of being resistant.

As the work progressed, I soon realized that it would be most difficult, or perhaps impossible, to locate resistant or immune trees in a region not so long exposed to infection; for, in such a region, one would have to inoculate all individuals suspected of possessing resistant qualities, in order to ascertain whether their healthy condition was actually due to resistant qualities or simply the result of a chance escape of infection. We therefore decided to restrict the work, for the present at least, entirely to a definite area about New York City. This area includes all of the territory within a radius of about 16 miles from New York City Hall, and therefore comprised in a general way, Greater New York and the adjacent parts of New Jersey.

RESULTS OF THE SURVEY

First I made a thorough canvas of Staten Island, doing the work on foot, aided by the trolley and the Staten Island R. R., and often guided by that genial naturalist and lover of Staten Island, Dr. Arthur Hollick of the Staten Island Institute of Arts and Sciences, I made a careful survey of the whole 64 square miles of which the island is composed. After two weeks of this kind of work, I began to get fairly well discouraged, not so much because of lack of results which, it is true, were entirely negative, but more on account of the appearance of the dead chestnuts. For where it was not entirely cut out, the bare, weathered poles showed that they had been dead for many years. The only encouraging feature was the finding of large quantities of healthy seedlings, from 7 years of age upward, to which I will refer later.

The Palisade region along the Hudson has been notable in the past for its chestnut forests. I next attacked this, making as thorough a search as possible from Hoboken to a little north of Alpine, N. J., which is a small place on the Hudson opposite Yonkers. Here also the vast forests of dead poles weathered gray with time, bore silent witness to the completeness of the destruction.

About the middle of July while ferrying across the Hudson, I noticed north of the landing at Dyckman St., what appeared to be chestnut trees in bloom. On investigation, I found these to be living native chestnuts, of the peculiar strip type I shall describe later, and proceeding further north from this, where the Harlem enters the Hudson. I was led into a forest where I found at least 40 living chestnuts, some of which were in good condition, and one particularly was leafy nearly to the top. (Fig. 1) Naturally, one would immediately suspect that somehow these trees had escaped infection, but this could not possibly be the case, for mixed in with them on all sides were bare, weathered trunks showing signs of old worn cankers, proving incontestibly that the fungus had been present here also for a long period. Shortly afterward, Dr. Olive, of the Brooklyn Botanic Garden, informed me that he had seen living chestnuts near Hollis, L. I., and at Valley Stream, L. I., and at each of these places I found a group similar to that near the Harlem.

These, in brief, are the high spots of the survey from the point of view of the scientist. In addition, I covered adjacent region of New Jersey to the west, including the Watchung Mt. range about Plainfield and the Oranges; the Bronx and Van Cortland Park and the country to Yonkers and the north, and to the northeast of New Rochelle. Long Island, as far as Hempstead, was also included. Altogether I travelled about 1200 miles on foot, not counting the distance traversed on trolleys and railroads. Always armed with opera glasses, I was careful not to use them when anyone was looking, for on the second day of the survey I had been arrested on the charge of being a German spy! I was also arrested on board a train in New Jersey for looking earnestly at a topographic map, then sharply out of the car window and noting what I had seen (dead chestnut trees) on said map. The carrying of a botanist's tin can (containing fungi, not bombs) was also an additional implicating circumstance on the latter occasion.

What then were the results of the survey? They may be stated briefly as follows:

1. No immune trees were found.

2. For the most part the older trees (from 20 years upward) were entirely dead, and had been so for a long period, as attested by the bare trunks, weathered a characteristic gray color which only time can produce.

3. However, large numbers of seedlings and young saplings were located, both healthy and diseased.

4. _The most important result was the finding of three well defined colonies of living mature trees; all of which, by virtue of characters to be presently described, are offering more or less resistance to the disease._

SEEDLING TREES

It is well known that seedlings and young saplings are naturally immune for a certain period, which varies in extent from 8 to 15 years beyond germination of the seed beginning, of course with the first formation of the seedling. Such immunity depends, however, not on any inherent characteristic, but on the fact that at this period the bark is usually smooth, sound, and free from wounds of any sort where Endothia spores and mycelium might enter. Of course, when wounded from any cause whatever during this period of youth, this immunity ends, so that the condition might perhaps be termed physical, in contrast to physiological immunity.

As I have already said, large numbers of seedlings, for the most part still unattacked, were found in many places in the area surveyed. There are of course no grounds for believing that such seedlings, descended as they are from non-resistant trees, are physiologically immune. Where they are free from disease, this exemption is due merely to the physical immunity I have just mentioned. Since they therefore represent non-resistant stock, they were used for comparative inoculation work, which will be referred to later.

I may as well say here as anywhere, that by resistance, I do not mean total resistance, for that would be immunity. There are, of course, degrees of resistance, in the plant world just as in the animal world. One person may resist a cold germ or the influenza bacillus better than another, that is, it will cause him only a little discomfort. Another person may not be affected at all, that is, he is totally resistant or immune. I say this because I have misunderstood when I have used the term resistance. The trees in the New York region show all grades of resistance, from individuals where the fungus makes very little headway in the bark, to cases where it grows almost as fast as in the average non-resistant tree.

CHARACTERISTICS OF THE RESISTANT TREES

What now are the characteristics of these resistant trees? How are we going to know one when we see it? I have outlined the leading features as follows:

1. BARK. In the case of this particular disease, it is obvious that the character of the bark is the most important feature since this fungus is primarily parasitic in the living cortex. In other words, the character of resistance must necessarily depend on the living cells of the cortex. Now, careful observation of the resistant trees reveals a most striking feature of the bark, namely its tendency to heal, by means of a callus growth around the margins of the lesions, whether large or small; and it is very apparent that this callus growth wards off the advance of the fungus for a time at least. When the callus growth is once formed, the fungus of the original canker encroaches on it very slowly, or often not at all. Inoculations in the callused margins of cankers showed usually only slight growth of the fungus after two months' time in the summer, or in some cases no growth at all. Several layers of wood could be counted underneath these callused margins--often 6 or 7--before reaching the annual ring exposed at the surface of the canker. This of course, shows unquestionably that the callus had remained healthy at that location for that period of time.

2. EXTENSION OF THE CALLUS TISSUE.--In many cases the callus tissue is of considerably greater extent than the normal area one would expect around a wound. It may even occur that the whole inner bark around the trunk is of a callused nature, without any open cankers showing at all. For example in a tree of which I have a photograph here (Figs. 2 and 4), the outer bark is sloughing off, revealing callused bark underneath of entirely different appearance, which no one would recognize as chestnut bark. This particular tree photographed represents an extreme in this respect. It seemed as if the whole tree was getting a new kind of bark, and yet this same character appears in all of the highly resistant trees. On cutting into this new callused inner bark it was found plentifully dotted with tiny _Endothia_ lesions, which however, never penetrated deeply. (Fig 4). Close to the cambium the white inner bark is quite healthy, generally for a thickness of 5-7 mm. That the mycelium in the small lesions was unquestionably the _Endothia_ mycelium, was shown by the appearance of the mycelium, and the presence of the _Endothia_ pustules in many of the spots. That these were not late infections, but only slowly growing small lesions, was shown by inoculations in such bark, which revealed scarcely any growth after two months.

One of the most resistant trees, the smaller tree near the center of the photograph, near the Harlem River, Boro of Manhattan, New York City.]

A very strikingly resistant tree at Valley Stream, Long Island, showing peculiar inner bark. The outer bark is sloughing off.]

One of the "strip" trees in the forest in the Boro of Manhattan, New York City.]

Showing the character of the inner bark of the Valley Stream tree (Fig. 2). At one place, near the center of the photograph, the bark has been shaved showing the small lesions caused by the fungus.]

3. THE WHITE SECRETION.--The most striking peculiarity of the callus tissue, is its abundant content of a thickish, milky, white substance. This came to light immediately when I cut into the callus, and it showed up very clearly when I shaved off the outer layers of dead cork tissue. The white material is not evenly distributed through the irregular grain of the wound tissue, but is particularly abundant in small spots or pockets which are especially conspicuous in the callused margin of the lesion. Soon after exposure to the air the cut bark, and particularly the white substance, redden rapidly, indicating oxidation. This peculiarity is of course true of all chestnut bark, yet here the reddening seems to be deeper and more rapid than the normal. No chemical analysis has yet been made of this substance, but there is sufficient other evidence at hand to warrant a tentative statement that it is very rich in tannin or tannin compounds, and that possibly the quality of resistance is bound up with the nature of this material.

4. THE STRIP CONDITION.--Some of the trees showed the living bark restricted to a narrow, flattened, rope-like strip running up the trunk to one or a very few branches (Plate 1, Fig. 3). In these cases all of the bark was of the callus nature, rich in the resistant substance, and plentifully besprinkled with small Endothia lesions, while underneath were a number of layers of functioning wood. The rest of the trunk was bare, weathered gray, with traces on its surface of old cankers, and evidently dead for a long period. This type of tree was so commonly found that I have called it the strip tree.

INOCULATIONS

The very fact that these trees are now alive in this New York region is pretty good proof of their resistance. But of course the most conclusive test is by inoculation with the fungus in question. If the fungus grows slowly in these trees as compared with its growth on non-resistant stock, then no one can deny that they are resistant. I will not bore you with figures of tables, I will only give you the results. The average growth of the fungus in 289 inoculations on the resistant trees was about 1/3 as fast as on non-resistant stock, and taking the rate of growth on those trees which are especially resistant it is about 1/4 as fast as on the non-resistant stock. For non-resistant stock the seedlings on Staten Island were inoculated, and the growth on these tallied very closely with growth in non-resistant trees inoculated by Anderson and Rankin.[3]

Another very striking result brought out by the inoculation work was that of the 158 inoculations on branches and basal shoots of the resistant trees, only nine had been girdled after one month's growth, while in the same time 16 out of the 32 non-resistant Staten Island trees were girdled. At the end of the second month, the results were still more striking. Then, in the Staten Island trees, 22 out of 32 were girdled, while in the inoculations on the basal shoots and branches of resistant stock only 22 out of the 153 resulted in girdling. This striking difference was not due to smaller diameters of the Staten Island trees, for particular pains were taken to have them approximately equal to the branches and shoots inoculated in the resistant trees.

SUMMARY OF EVIDENCES OF RESISTANCE

We may summarize the evidences of resistance as follows:

1. The results of the inoculation tests show that the fungus grows in these trees on the average from 1/4 to 1/3 as fast as in ordinary chestnut.

2. The occurrence of the trees in a neighborhood long subjected to the disease, and their presence among the trees of individuals long since dead.

3. Indications of the long period the disease has been present in the trees themselves; such as bare weathered tops, and healed cankers.

4. Peculiarities of the bark; such as extensive development of the callus tissue, and the presence of a peculiar substance or white secretion which is particularly conspicuous in cases of marked resistance.

IS THE DISEASE RESISTANCE HERE AN HEREDITARY CHARACTER?

As to whether this disease resistance is an inherent character and will be transmitted from generation to generation, or is only the result of particularly favorable environmental conditions such as soil, light or moisture, is a point of great practical importance. I believe that further work will prove that the resistance is heritable, for the following reasons:

1. The resistance is not due to a particularly favorable environment of the trees, for the three groups grow in very different soils and under varying conditions of light and moisture.