DR. MORRIS: In brief, I have some very superior chestnuts. They will be valuable for horticultural purposes in other parts, or in non-blight regions, of the country. I have kept them going by care and attention. I would be very glad to send those out of Connecticut, provided that the way may be found, by sending them through Washington to other states. It would be necessary, however, to have the scions treated in such a way as to make sure that the endothia spores had been destroyed.
THE PRESIDENT: I suggest that Prof. Collins give the matter some thought, and when he gives his paper he will be able to inform us about that. We will now ask Mr. Reed for a report as to promising seedlings.
MR. REED: There are quite a number of new things which might be mentioned. One is a group of Chinese walnuts now in their second or third year in the nursery of Mr. Jones, at Lancaster. In this lot there are many beautiful young trees grown from nuts obtained for Mr. Jones by Mr. P. W. Wang, of Shanghai. They are from North China, the territory which I visited more than two years ago and from which I also obtained considerable seed. Of the latter we have now several hundred seedlings ready for distribution. Personally I would like them to be distributed among members of this association. Mr. Jones has 300 or 400 of the Wang trees which he proposes to sell as seedlings. Others will be used as stocks for grafting varieties of regia.
Dr. Morris has already referred to the Chinese chestnuts. Mr. Dorsett, of the U. S. Department of Agriculture, has recently arrived in China for a two-years' trip. He will doubtless send many chestnuts.
Another particularly interesting group of nut trees is a lot of hazel-filbert hybrids produced by Mr. Jones. These are between the Rush and the Barcelona, or other European varieties. He now has plants three to five years of age in bearing. They average as high as a man's head. Practically all are in bearing with attractive clusters of nuts, and some are fruiting heavily. The Rush variety, as most members know, is a native hazel of unusually prolific habits of bearing. The nuts are of fair size and quality.
Recently I have seen some interesting pecan trees in the East. Two of these are on the Eastern Shore of Maryland, one in the outskirts of Easton and the other at Princess Anne; the former is a trifle the larger, measuring 15 ft 5 inches in girth at breast height, the latter measuring 4 feet and 2 inches at the same distance and estimated to be 110 feet high. It was grown from a nut said to have been planted in 1800. The nuts from these trees are small but well filled and much appreciated by their respective communities.
THE PRESIDENT: We have the secretary down for a paper.
THE SECRETARY: This paper opens a symposium on topworking hickory trees.
By W. C. Deming, Connecticut
I do not recall a single modern improvement of importance in the art of grafting nut trees in the North that is not due to either Mr. Jones or Dr. Morris, except that to Mr. Riehl belongs, I believe, the credit of the idea of waxing the entire graft, which is now the accepted procedure. Therefore I speak before these two gentlemen with diffidence. I do so in the hope that perhaps I may recall something which they have forgotten to make known, or that what I say may elicit from them available emendatory remarks. My experience of fourteen years on my own place, and of five years grafting for others, is the basis of my observations.
Compatibility of Species and Varieties
This question will be particularly discussed by Mr. Bixby who has been conducting careful experiments that should soon settle the question for the commoner hickories. A few scattering observations of my own may be useful.
It is generally believed that any species of the genus hickory will catch on any other, though not necessarily that the union will be blessed. It is self evident that any hickory will thrive on any variety of the same species, shagbark on shagbark, pecan on pecan, though even here close observation will probably disclose differences of compatibility. Probably any hybrid hickory will thrive on either of its parents. In some cases this may turn out to be a test of hybridity. For instance, the Barnes is one of the few shagbarks known to thrive on mockernut. It shows other evidences of mockernut blood.
I have found no hickory, so far, that does not appear to thrive on the shagbark, except the pecan. Even here there are differences. I have one Major pecan on shagbark that is over twenty-five feet high that has a very healthy appearance and that has shown staminate bloom for two or three years. I have also an Indian pecan that looks fairly prosperous. The Iowa pecans, the Marquart, Greenbay, Campbell, Witte, and others, catch readily and grow vigorously, at least for the first years. There are many data, however, on the adaptability of the pecan to the shagbark and the consensus of opinion is that ultimate results are poor. This is probably because the shagbark starts early and makes its season's growth in about six weeks, while the pecan naturally has a much longer growing season. However, these observations have been made, mostly, in the South and it may be different in the North. The question is not yet finally decided.
The Stanley shellbark, H. laciniosa, is completely at home on the shagbark, apparently, but has not yet borne with me.
The Hatch bitternut grew luxuriantly on shagbark for a year but blew off.
The Zorn hybrid made a growth of one foot on shagbark but then was winter killed, apparently.
I have a back pasture full of vigorous pignuts, H. glabra, which for eleven years I have been grafting with faith which now seems childlike, that soon I would have fourteen acres of bearing hickory trees. Yet as a result of all these years of grafting the only hickories that I have found to thrive are the Brooks, which appears to be vigorous, the Terpenny, which is vigorous and bearing nuts in its fourth year, and possibly the Barnes. Not a single pecan survived more than a year, though many started. The Beaver hybrid makes a long spindling growth and then, in the first or second year, the leaves turn yellow and mosaic and the growth dies. The Kirtland, Kentucky, Hales, Taylor and several others, have all with me, proved failures on the pignut. Mr. Bixby's experiments appear to be showing somewhat different results.
The question of the compatibility of species and varieties is really a very important one because in some localities either the pignut or the mockernut is the prevailing species, and we wish to know with what species and varieties they may be successfully grafted. For instance, if the Barnes, which is an excellent shagbark, will do well on both the pignut and the mockernut, where so many other varieties fail, and the Brooks is at home on the pignut, these are highly important facts to be known by the man with fifteen acres of hilly woodland full of young pignuts and mockernuts.
Size of Stocks
I prefer stocks of moderate size, up to three inches in diameter. One gets greater results for the labor with these than with larger trees. Of course a tree of any size may be topworked but the labor is disproportionately greater, especially in the after care.
Cutting Back Stocks for Topworking
I doubt if it is important to cut back stocks during the dormant season, except that then there is more time. With larger trees this counts for a good deal, but in the smaller ones I like to cut them off just where I want to graft at the time of doing so. However, they may be cut off when dormant at the point of selection for grafting and later grafted without further cutting back. This reduces, or does away with the risk of bleeding. Except in very small stocks it is better to leave a number of the lower branches to prevent bleeding. When bleeding does occur it may be checked by making one or more cuts with the knife or saw into the sapwood of the trunk below the graft. Better results come when the cutting back is of the top branches and not the lower ones because of the stronger flow of sap toward the top of the tree. In my opinion a side branch should always be left at the point where the stock is cut off to maintain a circulation of sap. Otherwise the stub will often die back and the graft fail. Also, the cambium close to a side branch will be observed to be thicker and I infer that the circulation of sap is more active. I prefer to cut off the top half, or two-thirds of the tree and graft into the top and the side branches near the top.
Hickories in full foliage may usually be cut back without evident harm. Occasionally a tree will be apparently shocked to death. Sometimes when a tree in foliage is cut back severely the remaining leaves will turn black and partly, or completely, die, but the tree will throw out vigorous new growth later.
Trees up to three inches in diameter may have the whole top cut off, at the risk of occasionally shocking a tree to death. Such complete cutting back must be done in the dormant season or there will be severe and prolonged bleeding. This method has the advantage of forcing a tremendous growth in the grafts which will need careful support. This is much more easily done however, than when the grafts are in the top of the tree. Cutting back in the dormant season and painting with paraffine has not worked well for me as the paraffine has not adhered well for any length of time to the freshly cut surfaces. Probably this could be easily remedied if it were a real advantage. In the case of small stocks and branches where there is no bleeding and the paraffine adheres well green callus will often be seen spreading out beneath the paraffine over the cut surface.
Stocks should be vigorous. Dwarfed, stunted, submerged, hide bound trees make poor stocks. This is important, I believe.
Scions
The condition of the scion is the most important element for success in top-working hickory trees. The technique of grafting has been so simplified as to make it fairly easy, and native stocks are usually vigorous. But unless the scions have full vitality success will be limited. They should be plump and not pithy. A limited success is possible with scions of feeble growth, or those subjected to devitalising influences in keeping or handling, but the largest success will be had with well grown scions, cut from vigorous trees or grafts, whose buds are completely dormant, and have a fresh, green appearance on cutting. When the cambium layer shows a yellowish or brownish tint the scions are useless. Slender wood may make good scions but is more difficult to keep in good condition. Heavy wood from vigorous, young, grafted trees, or from cut back trees, makes the best scions and is the easiest to keep. Wood more than 1 year old and as large as one can handle makes good scions. Dr. Morris, with the use of the plane, has succeeded with astonishingly large scions and even branches. Sometimes buds are absent from these large scions or are very inconspicuous. They may be searched for with a lens.
Preferably scions should be cut when entirely dormant. Buds that show signs of breaking should be removed. Scions cut after growth starts may be used with success if there are dormant buds. This "immediate grafting," as Dr. Morris calls it has not been fully studied. It may be of great value. It is quite successful with the apple and the pear. It appears to depend chiefly on the presence of dormant buds of vitality.
The later in the season the dormant scions are cut the shorter the time they have to be kept, though probably this is not of importance if the method of keeping is right.
Keeping Scions
The larger the scion the easier it is to keep it. Dr. Morris cuts whole branches and keeps them in the sawdust of his icehouse. I have cut them two inches in diameter and kept them lying uncovered on the barn cellar floor into the second summer looking fresh and green. The smaller the scion the more susceptible it is to moisture environment. Scions must be kept where it is neither too moist nor too dry. Usually the mistake is made of keeping them too moist. The buds may start if the scions are too moist even when the temperature is quite low. This happened for me when I stored scions for a week or two in the very cold bottom of an icebox. The most successful grafters keep scions with a sort of intelligent neglect. Dr. Morris buries them in the sawdust of his icehouse and it seems to make no difference if ice is there or not. I once tried keeping them in an icehouse over the ice and they became soaking wet. I have noticed that Dr. Morris's sawdust seems quite dry. Mr. Jones keeps some, at least, of his in bins or barrels covered with burlap bags. He says that heartnut scions keep best not packed away but kept in the open cellar. I notice that Mr. Jones has been using some kind of mill planings in place of sphagnum moss. Branches and large scions will keep well in a medium that seems dry to the touch. Small scions, such as those cut from old parent trees, require careful handling to prevent shriveling, on the one hand, or bud starting on the other. A low temperature is probably desirable, but the right condition of moisture is essential to the proper keeping of scions for any length of time. I should naturally prefer to keep them in darkness, but I am not sure that it is important. Undoubtedly the access of some air is necessary but it would be difficult to keep it altogether away. I do not know how long scions would keep if entirely covered with paraffine. One year I dipped all the cut ends of my scions in melted paraffine but I am not sure that it is worth the trouble. One year I packed away my scions in rather moist sphagnum moss. The first time I looked at them they were enmeshed in mold mycelium. Later many of the buds started to grow. As suggested by Mr. Jones, dipping either the scions or the moss in half strength Bordeaux mixture will remedy the mold trouble. Parenthetically, this should be of help in keeping chestnuts, chinkapins, and other nuts that spoil easily with mold, for planting in the spring. Packing scions tightly and heavily covered in boxes for any length of time has been, in my observation, disastrous. In shipping scions a method advised, and one that I have followed with satisfaction, is to wrap the scions, either separately or together, in paraffine paper without any packing next the scions but putting it, instead, outside the paraffine paper. This packing may be sphagnum moss or mill planings slightly moistened. This also is wrapped in a moisture impervious covering and then in ordinary wrapping paper. For shipping long distanced the moss or planings should be dipped in half strength Bordeaux mixture.
The surface of the bark of scions that are being kept should always be dry, never moist. But they should never be so dry as to look shrivelled. Until you know just what scions will do under the conditions you provide you should examine them frequently.
Equipment
The essentials are a knife, raffia and the wax heater with brush. A saw is necessary if stocks are to be cut back, and pruning shears are convenient for cutting scions into proper lengths and for trimming and pruning stocks. The knife most used is the grafting knife of Maher & Gross, with a three inch straight blade and a round handle that gives a good grasp.
I used to suspect that the men who said that scions ought to be cut with two strokes of the knife were trying to establish an unattainable ideal. But after Mr. Jones and Dr. Morris had taught me how to sharpen my knife I found that I could cut one that way myself sometimes. Mr. Jones's method of sharpening is to hone the knife flat on the surface next the scion and with a bevel on the upper edge. I found that this made scion cutting so much easier that I thought it was the whole secret. But one day I saw another doubter come up to Mr. Jones and ask him if it was true that he could cut a scion with two strokes of the knife. Mr. Jones said he thought he could but he had no knife just then. The man pulled out his pocket knife and asked if that would do. Mr. Jones looked at it, took a stick and with two strokes cut a perfect scion. Since then I have felt that there is something to it besides the way you sharpen your knife.
A very important element in shaping scions is to give a drawing motion to the knife by keeping the handle well advanced before the blade. The cutting is done with a draw and not a push. This is one of the most important factors for success in shaping scions.
It seems hardly necessary to say that the stroke of the knife should be away from the grafter. Yet it is a common sight to see beginners cutting to the thumb.
Dr. Morris showed me that if, in sharpening your knife, you hold the little whetstone between the thumb and middle finger of the left hand you are less likely to put a feather edge on it. A feather edge is something to clip the sprouting wings of any budding saint of a grafter. When you get the right edge on your knife often you can use it the whole day without resharpening, or at most with simply a stropping on a piece of wood or leather. But improper use of the knife, or the least knick, will spoil the edge and sometimes it will be quite difficult to get it back. Therefore the blade should always be protected by a sheath, never laid down or used for cutting raffia, or anything but the actual cutting of the graft. For this purpose a leather sheath worn on the front of the belt, as first used by Dr. Morris, is almost a necessity. This sheath may be made by any leather worker and should have at least two pockets, one for the grafting knife and one for another knife to be used for trimming, cutting raffia and other odd things. It is convenient to have a little pocket for a pencil also and one may provide places for other articles of equipment at fancy.
I do not know that there is much to be said here about raffia. But a great deal has been said, and will be said, elsewhere, when the raffia is rotten and breaks in the middle of tying a graft. It is the devil's own stuff to carry when you don't carry it right. The right way to carry it is to tuck one end of the bundle under one side of your belt, pass the bundle behind your back and the other end under the other side of your belt. Then the raffia never gets mixed up with scions, tools and profanity and the end of a strand is as handy as the knives in your belt. On the whole I do not know of any binding material as satisfactory as raffia. It is stronger and easier to use when it is damp.
One of the great advances in the art of grafting is the use of melted wax. I believe that we have to credit Mr. Jones for this. The use of paraffine for grafting wax we owe to Dr. Morris. To him also we owe the Merribrook melter which has added so much to the comfort and convenience of grafting that it can be recommended as an outdoor sport for ladies. I do not like the brush that Dr. Morris recommends but prefer a stiffer one such as can be bought for ten cents.
Equipments vary with the individual and with the difference in the work to be done. Mr. Slaughter carries into the nursery, when he is working for Mr. Jones in the semi-tropical sun of Lancaster, a stool with parasol attachment. Mr. Biederman of Arizona has the most elaborate equipment which includes a table, planes, curved knives and gouges. Dr. Morris carries a knapsack. I like an ordinary light market basket that Mother Earth holds up for me when I'm not moving from place to place. When in a tree I stuff my pockets with scions.
A saw is usually a necessity. For portability I prefer a curved one that has a draw cut. It has also an aesthetic element and doesn't look like a meat saw, which can't be said of Mr. Jones's saw that seduced Dr. Morris from church. For heavy and steady work I much prefer a carpenter's sharp hand saw. A two-edged saw is an abomination devised by conscienceless manufacturers for the seduction of innocent amateurs.
For pruning shears I have a personal fancy for the French, hand-made instrument, each one individual, a work of art and a potential legacy to one's horticultural heir, if one doesn't let the village blacksmith monkey with it, as I did with mine.
On some grafts it is desirable to use a bit of paper, either beneath or outside of the raffia, to make waxing easier. For this I have found scraps of Japanese paper napkin very adaptive to surfaces and absorptive of wax.
On very heavy grafts Dr. Morris uses the Spanish windlass, as devised by him, for which he carries sisal cord, wooden or metal meat skewers, small staples and a mallet. He uses a chisel to cut slots in very thick bark and planes for shaping heavy grafts.
I have tried fastening in grafts with a nail, using iron and brass nails and bank pins. Mr. Jones has suggested cement covered nails. My experience with iron nails is that they damage the scions. The use of nails has not been fully worked out. They are almost essential in bridge grafting apple trees. I think that just the right kind of a staple might be a help with some kinds of grafts.
Paper bags, 2 pound size, are sometimes wanted, for protection from sun or insects or to make the grafts conspicuous. Mr. Jones shades grafts made close to the ground with a slip of paper.
For labels for immediate use the wooden ones, painted on one side and with copper wire fastening, are satisfactory. Attach them by the nurseryman's method, which it has taken me many years to recognize as the right one, by twisting the doubled wire around a convenient object. Do not separate the wires which will probably permit the label to flap in the wind and soon wear out the wires. I used to think that the nurseryman's method was the result of hurry or laziness.
Copper labels, to be written on with a stylus, cost 1-1/2 or 2 cents each, according to size. The smaller I consider preferable. I imagined that these would solve the label problem. Picture my disappointment when I found that many of them cracked, or broke off entirely near the eyelet, from flapping in the wind. If they are to be used they must be fastened so as not to move with the wind. Mr. Bixby has an excellent label made on an aluminum strip printing machine. It has a hole in each end and is fastened with a heavy copper wire. He uses two of these labels on each tree. Dr. Morris sometimes uses a heavy wire stake to which he fastens the labels. A good method of attaching labels, and one that does away with the risk of girdling the graft or tree, is to fasten the label to a staple driven into the tree. The matter of labels is a troublesome one for they will get lost no matter what you do.
Other conveniences of equipment are a small whetstone, a small hammer, matches, and some volatile oil, like citronella, lavender, wintergreen, or other black fly and mosquito repellant. It is almost suicidal to slap a mosquito on the back of your neck with a keen grafting knife in your hand. A supply of parowax and alcohol for the lantern's sake should be remembered.
Technique
If the stocks are vigorous and active, and the scions full of vitality, I doubt if the technique is of chief importance, provided it is ordinarily good. However, a good technique will increase the percentage of success. One should have a variety of methods at command for varying conditions of stocks and scions.
One may come as near 100% success in grafting hickories as one is able and willing to observe all the known factors of success. I think that we can say now that the factors of success in hickory grafting are known. They are a vigorous and active stock, a scion of abundant vitality, coaptation of the freshly cut cambium layers and prevention of desiccation.
The stock and scion have already been considered. How is coadaptation best obtained? One of the best methods, one that can be used in all seasons and in most conditions of stock and scion, is the side graft, the one that Mr. Jones uses in his nursery work. That is the best argument for this graft. It is, perhaps, the simplest, and at the same time one of the most difficult, of all grafts. The scion is cut wedge shaped and pushed into a slanting incision in the side of the stock. Mr. Jones's modified cleft graft is only a side graft made in the top of the stock after cutting it off. The difficulty lies chiefly in cutting the scion and the incision in the stock so that the fit will be perfectly true. This requires practice.
The bark slot graft, as Dr. Morris calls it, I have used for several years. It can be used only during the growing season when the bark will slip. It is very successful, whether put in at the top of a cut off stock, or inserted in the side of a limb or the trunk. It is not convenient to use unless the scion is considerably smaller than the stock. The scion is cut with a scarf, or bevel, on one side only. When the slot is to be made in the top of a cut off stock two vertical cuts are made through the bark, as far apart as the scion is wide, the tongue of bark thus formed is raised slightly at the top, and the point of the scion is inserted, cut surface toward the center of the tree, and pushed down firmly into place. The superfluous part of the tongue of bark is then cut off. By slightly undercutting the edges of the slot, and slightly tapering it toward the bottom, the scion may be wedged, or dovetailed, in place so as to be very firm. It is even possible to dispense with tying, sometimes, but better not to do so.
When the slot is to be made in the side of a limb or trunk the same procedure is followed except that it is necessary before making the slot to remove a notch of bark, at right angles to the axis of the trunk, so as to free the upper end of the tongue of bark.
The bark slot graft is the easiest of all and readily mastered once the grafter learns to shape a true scion. It is much better than the old bark graft where the bark of the stock is forced away from the wood leaving considerable space to be filled or covered.
These two forms of graft, the side graft, of which Mr. Jones's modified cleft graft is only a variation, as before stated, and the bark slot, in its two variations as described, will meet all needs in topworking hickory trees.
Finally, prevention of desiccation of the graft is obtained by waxing. I have found Dr. Morris's method with melted paraffine satisfactory. The addition of raw pine gum, as advocated by Dr. Morris is undoubtedly an advantage under certain conditions, described by him, but I have not yet used it. The melted parowax is applied to the whole graft and wrapping, leaving no cut surface exposed and the whole scion being covered. If the paraffine is at just the right temperature it will spread at a touch, covering the surfaces without danger of scalding. It is much more effective thus applied than if colder and daubed on. The thicker the waxing the more likely to crack and separate. If the paraffine smokes it is too hot. If it does not smoke, and is dexterously applied, I think we can feel safely that it cannot be too hot. But if applied with a heavy hand it may be too hot even at a temperature so low that it will not spread.
Season for Grafting
According to Dr. Morris nut trees can be grafted successfully in any month of the year. But practically I think that grafting will be limited to that part of the year during which the cambium layer of the stock is active. At other times of the year preservation of the vitality of the scion will be too problematical, it seems to me, even if it is very carefully waxed. However, I may be mistaken. At any rate grafting is not very pleasant work out of doors in very cold weather. The success of bench grafting would be an argument for the success of dormant season grafting out of doors.
After Care
Without thoughtful after care the labor of topworking will almost certainly be lost. There are many ways in which the grafts can be lost but the two commonest are by being choked, or inhibited, by growth from the stock, and by being blown out by the wind. All new growth from the stock must be rigorously prevented. Grafts often make so heavy a growth that, if not blown out by the wind, they will be dragged out by their own weight. Consequently they must often be supported. When the grafts are in, or near, the trunk of the stock, and not too high, the handiest method of support is to cut a sapling of proper length, sharpen the butt, stick this into the ground at the base of the stock, and tie it in two places to the stock. When the grafts are too far out or too high for this method laths or slats or sticks may be tied or nailed to the branches. Support is likely to be even more necessary in the second season when the growth is often astonishing.
Bud worms will sometimes destroy your graft just as it is starting, but they are easily found if looked for. With my conditions the most harm by insects is done by the night feeding beetles, which are particularly exasperating as morning after morning you watch the progress of their destructive work without ever seeing them. Bagging is the only preventive and it pays to use bags when a particular graft is cherished.
Is Topworking Hickories Worth While?
Up to the present time it is the surest and easiest way, practically the only way, of getting good results with the hickories, excepting the pecan. The root systems of the native stocks are well established and push the grafts rapidly. I have had a Siers hybrid grow 11 feet Straight up in a season. A Taylor matured several nuts on the third season's growth. A Terpenny had a crop the fourth year, the Griffin bears annually since its fifth year, the Kirtland and Barnes since the sixth. The Kentucky is a little slower. None of the hybrids have yet borne with me but with others they have borne quite early. We can be sure that the hickories will bear when top worked as soon as the average apple tree. The size of the crop that any topworked hickory tree will bear will depend on the size to which you have been able to grow the tree and the habit of bearing of the particular variety. I think, also, that there is good evidence to show that the size of the tree, the size of the nuts and the size of the crop will depend largely on the amount of care and the amount of plant food that is given the tree.
Two years ago I topworked a number of hickory trees for Mr. Patterson of Wilkes-Barre, one of our members, and Mr. Patterson's foreman put in a few grafts under my observation. This summer I went to Wilkes-Barre to inspect my work. The foreman took me out into a field where he had done a lot of grafting the year before and I found that he had had a little better percentage of success than I had had. He had used the bark slot graft for everything, even when the scions were almost as big as the stocks. Before this I had thought that long experience was necessary for successful grafting. Now I see that if you have good scions, a Morris melter and a half hour of instructions, you will have all the essentials for immediate success. Hickory grafting is easy now. But let no one be contemptuous, for this ease has come only after many years of experiment and countless failures by many men. The former difficulty in grafting the hickory seems now like a mystery. The history of its evolution would make a very pretty story for the nut grower.
By Dr. R. T. Morris, Connecticut
Any newly described fact which releases information on the subject of tree grafting opens vistas of the new frontier in world agriculture.
Time was when men went from one country to another in search of fresh top soil. That was when they did not know better. It was when their cogs of habit turned their cogs of thought. They were engaged in raising annual plants at a considerable expenditure of time, labor and expense. They committed wastage of soluble plant foods (a variety of sin).
Malthus formulated a famous over-population fear-thought. It had basis in his ignorance of the fact that steam was soon to become a factor in the spreading of food supplies. Furthermore, he seemingly did not know that when old top-soil frontiers had gone to the rear, new frontiers would appear in the sub-soil. The tree digs deeper than the farmer ever plowed.
After Malthus came hunger prophets who were ignorant of coming possibilities of fleet transportation through the air. The caterpillar tractor plunging into the tropical jungle will allow of the production of a practically unlimited food supply. Famine in India, China, and Russia is a social matter and unnecessary. Trees cure famine.
Within the past decade a number of thinkers on one end of the see-saw have written heavily on the over-population question not knowing that they and their birth control ideas were to be tossed into the air by still heavier weight of fact on the other end of the see-saw.
The heavier weight of fact relates to the idea that famine does not belong to tree food regions. It relates to the fact that tree foods can supply all of the essentials of provender for men, livestock and fowls; proteins, starches, fats and vitamines in delicious form. It relates to the fact that tree foods come largely out of the sub-soil without apparent diminution of fertility of the ground. The tree allows top-soil bacteria and surface annual plants to manufacture plant food materials and then deep roots take these materials to the leaves for elaboration by sun chemistry.
Trees may be grown wherever crops of annual plants may be grown and where annual plants may not be grown profitably. They do not require the service of high cost labor for annual tillage of the soil. For example, four large pecan trees or black walnut trees on an acre of ground without tillage or fertilizer may average a thousand pounds of nut meats annually for a century. How often is the market value and food value of a thousand pounds of nut meats per acre equalled by crops from annual plants which would require from 100 to 200 plowings and harrowings during a hundred years of continuous cultivation leaving out the question of expensive fertilizers and labor. Large populations live upon dates, olives and figs. For trouble they have to look to religion.
Several centuries were required for the British farmers to raise the wheat crop from six bushels to thirty bushels per acre. Things move faster nowadays. It will not require so long a time to carry tree crops from the seedling phase to the phase of grafted kinds with greater productivity and quality. In the past the successful tree grafter was a specially skilled man. Now almost anybody may graft almost any sort of tree at almost any time of the year.
Aside from grafting, the hybridizing of nut trees, like that of cereal grain plants, has become a scientific sport appealing to the play instinct of man. When work becomes play in any field of human activity progress goes by leaps and bounds. The recent advance in tree grafting has amounted almost to a revolution rather than an evolution process. Application of a few new grafting principles of great consequence is now the order of the day. Old established grafting methods frequently ran into failures when dealing with all but a few trees like the common fruit bearing kinds.
The two chief obstacles to successful grafting were desiccation of the graft and fungous or bacterial parasites which entered the land of milk and honey where sap collected in graft wounds. Both of these dangers have now been practically eliminated and it remains for us to extend the season of grafting, carrying it away from a hurried procedure in busy spring weeks.
The chief obstacle to this extension of the grafting season has been the difficulty in finding the right sort of grafting wax or protective material for covering the graft, buds and all, as well as the wound of the stock. For covering the entire graft in order to avoid desiccation grafting waxes had to be applied in melted form with a brush. They had to be applied in melted form for filling interstices of wounds in which sap might collect and ferment. These waxes had the effect of not retaining their quality under greatly varying conditions of heat, cold and moisture. The paraffin waxes which the author has preferred were inclined to crack and to become separated from the graft and stock in cold weather. Furthermore they would remelt and become useless in the very hot sun of southern latitudes.
Experimentation for several seasons has resulted in the finding that raw pine gum is miscible with the paraffins in almost all proportions because of physical or chemical affinity. This gives to the wax an elasticity and adhesiveness of such degree that we may now graft trees in cold weather. Cohesiveness of molecules of the mixture is such that remelting in the hot sun may not destroy the effectiveness of this protective coating in hot weather.
Since the author has depended upon this mixture he has grafted peaches, apples, hazels and hickories successfully in midwinter as well as in midsummer. Many other kinds of trees have been grafted successfully out of the so-called grafting season but these four kinds which represent two of the "easiest grafters" and two of the "hardest grafters" will suffice for purposes of illustration.
According to old-established idea trees may be grafted successfully only from scions that have been cut when dormant and stored in proper receptacles. This is what we may term "mediate grafting," a considerable length of time intervening between cutting the scions and inserting the grafts. On the other hand what we may call "immediate grafting" is the taking of a scion from one tree and grafting it at once in a tree that is to receive it. Mediate or immediate grafting may both be done at almost any time of the year, winter or summer, spring or autumn.
When preparing the scion for immediate grafting in the spring or early summer it is best to cut off all the leaves and herbaceous growth of the year. We then depend upon latent buds situated in the older wood of the scion. The latter may be one year or several years of age.
In midsummer when top buds have formed we may remove only the leaves, allowing the growth of the year to remain and to serve for grafting material.
In experiments with the apple for example it was found that mediate grafts inserted on July 10th in the latitude of Stamford, Conn., began to burst their buds five or six days later. Immediate grafts inserted at the same time began to burst their buds about fifteen days later from buds of the year and about twenty days later from latent buds in older scion wood.
New shoots from these mediate apple grafts continued to grow as they do in Spring grafting. Immediate apple grafts on the other hand put out about six leaves from each bud and then came to a state of rest with the formation of a new top bud. After about ten days of resting these new top buds again burst forth and grew shoots like those of the mediate grafts.
The philosophy of these phenomena would seem to include the idea that the mediate summer grafts had contained a full supply of pabulum stored up in the cambium layer. The immediate summer grafts, on the other hand, had contained only a partial supply of pabulum, enough to allow them to make six leaves and a top bud. After a few days of resting these shoots with meager larder could then go forward with new food furnished by the whole tree.
Mediate and immediate winter grafts were alike in their method of growth in the spring. This would seem to confirm the idea that character of new growth is dependent upon the relative quality of stored pabulum in the cambium layer.
In experimental work it was noted that both mediate and immediate winter grafts make a slower start in the spring than do the grafts inserted in springtime. This is perhaps due to the formation of a protective corky cell layer over wound surfaces. New granulation tissue would then find some degree of mechanical obstacle in the presence of a corky cell layer at first.
Herbaceous plants allow of grafting. We are familiar with the example of the tomato plant grafted upon the potato plant, furnishing a crop of tomatoes above and potatoes below.
It seemed to the author that the herbaceous growth of trees should be grafted quite as readily. This seems to be not the case. A number of experiments conducted with grafting of the herbaceous growth of trees in advance of lignification has resulted wholly in failure with both soft wood and hard wood trees.
The walnuts carried herbaceous bud grafts and scion grafts for a long time however. These grafts sometimes remained quite green and promising for a period of a month but lignification progressed in the stock without extending to the scion. Speculation would introduce the idea that lignification relates to a hormone influence proceeding from the leaves of a tree and that the leafless scion does not send forth hormones for stimulating the cells of the scion to the point of furnishing enzymes for wood building.
Perhaps the most interesting part of new tree work relates to experiments which are failures. Negative testimony is like the minor key in music. There are many men who care to do only things that "cannot be done." These are the ones who have made our progress in almost every field of human activity.
Willard G. Bixby, Long Island
MR. BIXBY: The sheets which I am distributing to you contain tables to which I shall refer during this talk. But first I will give a little foreword regarding the trees. The trees enumerated in the tables shown were nearly all given me by Mr. Henry Hicks of Isaac Hicks & Son, Westbury, Long Island, and were taken to Baldwin and set out in the fall, practically the entire roots being saved and later the trees severely cut back. They were transplanted without loss except in the case of the shagbark, and those lost were all undersized trees. All of the hickories were of one age, but those lost were ones which had not made normal growth and had they been discarded in the beginning there would have been no loss whatever in the transplanting of 300 or 400 trees. Later, in the spring of 1924, I found some loose bark pignut (Carya ovalis) seedlings on a farm not far away from my place, and these were also transplanted; but they were too small to graft this year. These experiments in grafting, made during 1923 and 1924, have shown us some new things. With some of the walnuts we had 100 per cent success. With the hickories there was not 100 per cent success, but that was due to the fact that we were putting scions on stocks that were not congenial in many instances. You will notice the results as shown on the tables.
G—Grafts Set C—Successful Catches
—————————————————————————————————————————
Shagbark Mockernut Pignut Pecan Bitternut Total
G C G C G C G C G C G C %
Barnes 6 6 3 3 3 3 3 3 3 3 18 18 100.0%
Brooks 5 0 4 2 5 1 5 2 19 5 21.0%
Clark 5 1 5 0 5 2 5 1 5 2 25 6 24.0%
Fairbanks 27 17 27 17 59.3%
Gobble 1 O 1 1 1 1 1 1 1 1 5 4 80.0%
Griffin 1 1 1 1 1 0 1 0 1 1 5 3 60.0%
Hales 5 3 4 1 5 4 5 5 19 13 52.5%
Kentucky 5 4 3 1 5 4 5 4 5 1 23 14 61.0%
Kirtland 3 1 3 2 3 2 3 2 12 7 58.4%
Laney 6 4 6 4 66.7%
Long Beach 4 3 3 2 4 1 4 2 3 1 18 9 50.0%
Manahan 5 1 5 1 6 2 5 1 5 1 26 6 24.2%
Siers 5 5 5 5 100.0%
Stanley 3 3 3 2 3 3 9 8 89.0%
Taylor 4 3 3 3 4 3 4 3 15 12 80.0%
Vest 5 1 5 0 5 1 5 2 5 1 25 5 20.0%
Weiker 5 1 5 2 5 1 15 4 26.8%
— — — — — — — — — — —- —-
32 17 51 20 52 26 46 24 91 53 272 140
53.1% 29.2% 50.0% 47.0% 59.3% 51.5%
An inspection of the 1923 grafts made August 21, 1924 showed the following number growing: on shagbark 14, on mockernut 6, on pignut 26, on pecan 24, and on bitternut 16, the only place where there was any material difference being in the case of the mockernut where nearly three-quarters of the number of grafts growing last summer failed to grow this spring, in fact all varieties failed to grow excepting three, the Barnes, Gobble and Long Beach, all three of which I suspect from other evidence, have mockernut parentage. In the ease of those on pignut and pecan stocks there was no loss from 1923 and in some instances at least of those on shagbark and bitternut stocks the loss was due to outside causes, such as being broken off.
G—Grafts Set C—Successful Catches
————————————————————————————————————————
Shagbark Mockernut Pignut Pecan Bitternut Total
G C G C G C G C G C G C %
Barnes 8 7 10 4 18 11 61.0%
Beaver 5 1 5 1 20.0%
Brooks 11 8 10 5 21 13 61.9%
Clark 6 0 8 0 5 0 5 1 24 1 4.6%
Fairbanks 5 3 5 3 60.0%
Greenbay 5 0 5 0 0.0%
Hales 5 1 5 1 20.0%
Kentucky 5 2 4 2 9 4 44.5%
Kirtland 5 5 4 3 9 8 88.8%
Laney 5 3 5 2 10 5 50.0%
Manahan 6 2 6 2 33.3%
Mosnat No. 5. 7 1 7 1 14.7%
Mosnat No. 6. 10 6 10 6 60.0%
Siers 5 4 5 4 80.0%
Stanley 12 1 12 1 8.3%
Vest 10 3 15 5 16 5 10 3 12 3 63 19 34.2%
Weiker 5 3 5 3 60.0%
— — —- — — — — — — — —- —
16 3 122 52 54 21 15 4 12 3 219 83
18.7% 42.6% 38.9% 26.7% 25.0% 37.9%
In 1923, it was very evident that the Barnes was the only variety showing 100 per cent success on every stock. That was not repeated in 1924, but it still showed a high percentage of success.
From the comparatively modest percentage of catches, 51.5% on the average in 1923 and 37.9% in 1924, one might hastily conclude that the grafting was not skillfully done or that the grafts did not have proper attention afterward, but as noted above the grafting was done by Dr. Deming, whom I regard as one of the most skillful men that we have, and as the work on walnuts done at the same time showed 100% success with a number of varieties, I think any question as to the skill with which the work was done and the care the grafted trees had afterwards can be dismissed.
It is to be regretted that the number of scions at hand was not sufficient to repeat exactly the experiments of 1923 as well as to follow out the points suggested by the 1923 work, but as there was not enough for both, the latter was done.
The 100% success of catches of the Barnes in 1923 was not repeated in 1924; but the high per cent of catches on the mockernut, (7 out of 8 in 1924), is gratifying in view of the few varieties that we have that have shown adaptability to that stock. As the Barnes is one of our good varieties and there is such a wide section of the country where the mockernut is the prevailing hickory, it is believed this behavior of the Barnes will prove a valuable addition to our knowledge in top-working the hickory.
No variety as strikingly adapted for use on the pignut has appeared, but there are a number that have shown fair adaptability.
The varieties most desirable for top-working various species of hickories as suggested by this work supplemented by other observations of the writer, would be as follows:
Shagbark—Most varieties.
Mockernut—Barnes.
Pignut—Brooks, Kentucky, Taylor, Kirtland.
Bitternut—Beaver, Fairbanks, Laney, Siers.
It is useful to know that the Barnes is the only one especially successful on the Mockernut. By the spring of 1924, all grafts on mockernut had died except the Barnes, the Gobble and the Long Beach, and each of these is thought to have mockernut parentage.
In the cases of the pignut and the pecan stocks, all of the grafts successful in 1923 were still living in 1924. With the shagbark and bitternut most lived. As to pecans there is not much to be said; pecan varieties would usually be used for the topworking here.
The results of a few grafts set in 1924 on Carya ovalis and on shellbark seedlings which were 100% failures, are not noted, as the shellbarks were, in the judgment of the writer, too small for the purpose, and the Carya ovalis had been set out in the spring of 1924 but a few weeks before the grafting was done. In other words the latter had not become sufficiently established to make good stocks, and the former were not large enough. In each case there was not sufficient vitality available to expect success.
This brings out one point which has impressed me strongly; that is the need of having vigorous stocks if they are to be grafted or transplanted successfully. I feel that this point cannot be too strongly emphasized. If a stock either from youthfulness or inherent lack of vigor is not rapid growing it is almost useless to try to graft it or transplant it until it does show the needed vigor.
As to stocks to grow in the nursery with the idea of grafting them later, the two commonly used, the bitternut for the bitternut hybrids and the pecan for others, there is little further to be recommended at this time, although for some varieties, notably the Vest, a stock better adapted to it than any we now have is earnestly to be desired.
* * * * *
THE PRESIDENT: Are there any questions on these three papers on hickory grafting?
MR. REED: There are two points in regard to propagation which I believe should be mentioned; one is that these various methods that have been discussed make it possible to propagate successfully during a great portion of the year. By beginning early in spring with the dormant graft, and continuing throughout the summer, these methods can be made to follow one another so that if one fails still another can be used. These methods greatly prolong the season, and when it is not convenient to propagate at one period by the method proper to use at that time another can be employed at a different season.
The other point is that we are constantly learning more in regard to the influence of stock upon scions. For example, hickories on pecans seem satisfactory while the reverse is at least doubtful. Mr. Jones finds that sieboldiana is not a good stock for regia. We all find nigra apparently satisfactory as a stock for any species of Juglans. These conspicuous differences of influence of various species upon scions suggest the possibility of less, but perhaps quite as important, difference of varieties. It is one of the newer phases of study and experimentation which should be considered by all and reported upon to this association.
THE SECRETARY: At my place the Vest, used in top-working large shagbark hickories, has been very successful. I do not know any that have been more successful or that grow more rapidly than it does on the shagbark hickory.
DR. MORRIS: The Marquardt is successful at my place.
MR. O'CONNOR: I do not know why we have not had success with paraffine in a single instance. In grafting fruit trees I had excellent results. I thought that if this could be done on fruit trees why not on nut trees? But I am going to try with the hickory again. I am going to be more careful in selecting good, strong stock for that purpose, and I think in that way we should have better success.
DR. MORRIS: Did you not perhaps cover the buds of your hickory grafts too thickly with melted grafting wax? Might not that account for your failure? Hickory buds will burst their way through almost any thickness of grafting wax, but when the paraffines are used without pine gum admixture the paraffine over the buds is particularly apt to crack and to allow the graft to dry out.
MR. O'CONNOR: I did not cover the hickory grafts with melted grafting wax at all; I simply put them in like apple grafts with ordinary grafting wax.
DR. MORRIS: Practically all hickory grafts will fail under such circumstances, but practically all hickory grafts will catch if they are covered with melted grafting wax of the right sort, provided that the scions and stock are also of the right sort.
THE SECRETARY: May we now have the President's address?
THE PRESIDENT: Before I begin I wish to call to your attention this pamphlet regarding the fifth Mid-West Horticultural Exposition, to be held in the Hippodrome, Waterloo, Iowa, November 11 to 16, 1924. It will be under the auspices of the Iowa State Horticultural Society, co-operating with its afflicted societies and the Greater Waterloo Association. The exposition will cover the Mid-West territory, from Pittsburgh to Denver. I wish especially to mention the printed list of premiums on page 27. Mr. S. W. Snyder, Center Point, is superintendent of this department. Cash premiums in Department b-Nuts, amount to $289. In addition there will be a grand sweepstakes, a trophy cup, donated by a member of the Northern Nut Growers' Association, for the exhibitor winning the greatest number of points. Anyone interested could write to the secretary, Mr. R. S. Herrick, State House, Des Moines, for a printed premium list. If any members of our Association have pet nuts of a variety which they would like pushed to the front now is the chance. Snyder Brothers are offering special premiums for new nuts unnamed and unpropagated.
The object of this association, as defined in its constitution, is "the promotion of interest in nut-bearing plants, their products and their culture," and as its name implies, in the northern part of this country. Without going into detail it seems to me that we have achieved the object of our association, at least to the extent of making practical use of our accumulated knowledge. Public interest has been aroused, which may become stale. Articles have appeared in magazines and newspapers from time to time on subjects relating to nut culture. We are also on a continual lookout for new varieties, and those of our members skilled in the art are constantly improving and working out new methods of grafting and budding, particularly as evidenced by Dr. Morris' work entitled "Nut Growing." We know approximately how soon a grafted nut tree, especially the black walnut, will begin to bear. At Mr. Jones' Nursery, Lancaster, Pa., an Ohio black walnut tree in the nursery row bore a cluster of seven nuts 17 months after the graft was placed. Mr. J. W. Wilkinson, of Rockport, Ind., has demonstrated that grafted northern pecan trees bear early and abundantly for their size.
We have given advice conservatively in reply to all inquiries relative to nut-bearing plants, perhaps too much so. Much honor and credit is due to certain members of our association for their untiring work and efforts in its behalf. It is not necessary to mention names as I am sure most of you present know to whom I refer. Our annual reports testify to their splendid work.
From this time forward I believe we should adopt the policy of boldly advocating the planting of orchards of nut trees. The intending planter will decide for himself what variety he will plant, and as a guide he should judge from the wild varieties growing in his vicinity. By so doing he cannot go very far astray in what will be to him a new venture. Of course certain varieties will be restricted to certain limited areas. This applies particularly to the introduced varieties, as distinguished from the native nut-bearing trees.
The black walnut has a wider range than any of the other nut trees. Travel wheresoever you will about the country and you will observe wild black walnut trees growing almost on every farm. The planting of the Persian, or English walnut, as it is more generally known, has had more of a popular appeal, perhaps from the fact that we are accustomed to seeing clean, smooth nuts of uniform size of that variety in almost every grocery store, the kernels of which may be extracted without great effort. The black walnut, on the other hand, has been tolerated as a sort of poor relation, and has been given no particular attention, because we have been used to seeing it around. It has not been made to do its share of contributing towards its keep. Our earliest recollections of it bring to mind bruised fingers as a result of our endeavors to crack the nuts and the tedious work of manipulating a darning needle to extract the kernels, which we usually picked to pieces in the process. We now know that we simply did not have the right kind of black walnuts. We should put our accumulated knowledge to practical use to urge on every occasion the planting of nut orchards, especially of approved varieties of the black walnut. This I understand is what the United States Department of Agriculture is advocating, and we should co-operate all we can with the department in that recommendation.
It will, no doubt, be urged that sufficient grafted black walnut trees are not available for orchard planting on a large scale. This, no doubt, is true, but on many farms there are wild black walnut trees of a size suitable for grafting or top-working. Grafting wood may be obtained in larger quantities than the grafted trees. Those of our members skilled in the art have not been selfish in imparting their knowledge to others and are always ready and willing to instruct others in the art. Most owners of these trees would only be too glad to substitute profitable tops for their trees in lieu of their unprofitable ones.
I believe that at all our meetings we should have practical demonstrations in budding and grafting, as this will tend to arouse the interest of the uninitiated and will spur the initiated to greater perfection.
During the past year there has been a discussion relative to the calling of the black walnut by some other name. Personally I believe we should not attempt the change. The public will not understand and it will take them a long time to become educated to the change. Valuable time will be consumed in picking out a new name. Let us take the name as we find it. Properly handled, after the husks are removed, the walnuts will not be as black as they are painted, and besides, we do not eat the shell anyhow. The quality of the kernel will make its appeal. The trouble with all of us has been that too much attention has been given to the looks, rather than the quality, of our food stuffs. Quality has been sacrificed for looks. Various illustrations of this come to mind with all of us.
I believe success will attend the planting of black walnut orchards. This will encourage others to follow with orchards of other nut-bearing trees. Orchards of all kinds of fruit trees are being planted each year and the planters are content to wait until the trees are large enough in order to reap the benefits thereof. But somehow the impression prevails in the minds of many people that a nut tree should show results and yield profits soon after it is planted. In recommending to a lady of means that she should plant, as shade trees, northern pecans she promptly wanted to know how many bushels of nuts she would get off of the trees the next year.
Perhaps we place too much importance on selecting just the right spot and soil in which to plant a nut tree and thus cause the intending planter to be too timid in making a start. Those who know anything about trees know pretty well where it is not advisable to plant trees, especially those with a long tap-root. They can judge fairly well from the wild trees of the same variety growing round about.
As evidence of what a nut tree will do, those of you who have visited Devil's Den in Gettysburg Battle Field, have perhaps noticed a butternut tree, now quite old, growing out of the top of the cleft in a huge rock, having sent its roots down to the adjoining soil for nourishment. This tree has borne nuts even in its adverse situation.
For the benefit of those interested in the northern pecan, I wish to record the fact that a seedling pecan tree is growing in Clermont County, Ohio, on upland, not far from the eastern boundary line of Hamilton County, about five miles north of the Ohio River. The nut from which the tree grew was brought from Rockport, Indiana, and planted about forty-one years ago. The tree is quite large and bears nuts comparable with the wild seedling nuts that may be obtained from the Rockport district. If a seedling does this, you may readily see what a grafted tree will do.
THE PRESIDENT: We will now ask Prof. Collins for his address.
Prof. J. Franklin Collins, Rhode Island
The chestnut blight has now been with us for more than twenty years and has destroyed practically all the chestnut trees of the northeastern part of the country. It has spread in all directions from its original center in the immediate vicinity of New York City until it has reached the limits of the native chestnut growth in the northeast and north, and is steadily approaching its limits in the west and south. The disease, a native of China and apparently imported into this country on some Japanese or other oriental chestnut, found a more susceptible host in our native chestnut and so became a virulent parasite on this new host. It was not until 1904 that general attention was attracted to the disease. By that time it had obtained a strong foothold on the chestnuts of southeastern New York (particularly the western end of Long Island), in southwestern Connecticut, and in northern New Jersey.
All of you are more or less familiar with the efforts made in Pennsylvania, New York, and elsewhere in the northeast, in co-operation with the federal government, to control the disease. These efforts are now an old story to most of you and there is no need of repeating it at this time.
Early in the fight against the blight the attention of many of us was directed to locating possible immune or resistant species, varieties, or individuals. The search for resistant native individuals and the accompanying experiments in crossing and grafting various species and varieties has been kept up ever since. Foreign explorers have constantly been on the lookout, with more or less success, for chestnuts in other countries that might be resistant to the blight. It has long been known that most forms of the Japanese chestnut (C. crenata) were in general highly resistant to the blight. Later it was found that the more recently introduced Chinese chestnut (C. mollissima) was also quite resistant, although both the Japanese and the Chinese were far from being immune. Quite recently Mr. Rock, explorer for the U. S. Department of Agriculture, has brought a new chestnut from southern China for experimental purposes. Notwithstanding newspaper reports to the contrary the possibilities of this chestnut in this country apparently are unknown at the present time. Nobody seems to know if it will stand our climate, resist the blight, produce worthwhile timber or fruit; nor is its name known, according to late advices that have reached me.
Some years ago the late Dr. Van Fleet made numerous crosses between the Japanese and the American chestnuts, the Chinquapin, and other species and varieties. Personally, I have not been in very close touch with Dr. Van Fleet's experiments. Doubtless some of you know more about them than I do. Regarding these I will only say at this time that the work begun by Dr. Van Fleet is being continued by the Federal Bureau of Plant Industry, with Mr. G. F. Gravatt in direct charge of the work so far as the Office of Investigations in Forest Pathology is concerned. Mr. Gravatt is also testing out the value of scions taken from seemingly resistant native trees when grafted on resistant stocks.
Some years after the blight had destroyed most of the chestnut trees in the northeastern states we kept getting reports from various localities to the effect that the blight was apparently dying out. Many of these reports came from sources that made us doubt their value, but others came from more reliable sources. We have had opportunity to investigate a number of these reports and have usually found that the statement that the blight was dying out was, in a sense, strictly true, the reason being that the chestnut trees were entirely dead, except for sprouts. This fact naturally prevented the disease from showing us as much as in former years.
Some twelve years ago I noticed in Pennsylvania a sprout of an American chestnut about an inch in diameter which had a typical hypertrophy of the disease, apparently completely girdling the sprout at its base; also a girdling lesion farther up on the stem. The hypertrophy was such a pronounced one and in other respects such a typical example of the disease that I photographed it. A few years later I was surprised to observe that this sprout had increased to more than three times its former diameter and that the two diseased areas just mentioned apparently had disappeared—at least they were no longer in evidence except as rough-barked areas. To make a long story short this sprout is still alive and has increased in size and height each year. Although now (1924) it is considerably branched and makes a small bushy tree it is badly diseased in numerous places and is only partially alive, but the dead portions have not resulted from some half dozen of the original disease lesions (apparently girdles), but from later infections. The very fact that a sprout should have lived for more than twelve years in the center of one of the most badly diseased areas known to the writer seems at least to suggest the possibility that future chestnut sprouts may yet grow in spite of the disease and persist—at least in a shrubbery form if not as a tree.
The sprout to which I have just called attention is not an isolated case, but merely one of the most pronounced that I know about. In a careful survey in July (1924) of the region immediately surrounding the sprout just mentioned two or three other notable, but less pronounced, cases of a similar sort were discovered. In two cases fine looking branched sprouts some twenty feet high with healthy-looking foliage were noted. Both were diseased but the disease seemed not to be very conspicuous or virulent. In a recent survey of woodland in Rhode Island (July, 1924) much healthy foliage was observed and several large sprouts were found on which the disease (although present) seemed to be doing little damage when compared with its former virulence in the same general region.
I call attention to these cases primarily to acquaint you with the results of our latest observations on what seems to me to be cases of gradually developing resistance in some of the remaining sprouts. In all my intensive work on the blight between 1907 and 1913 I cannot now recall a single instance where a chestnut sprout in a disease-ridden area ever reached a diameter of an inch or thereabouts before its existence was cut short by the blight; and yet today—a dozen years later—we are finding quite a number of living sprouts over two inches in diameter, and a few that are three, four, and even up to seven inches in diameter. Last Friday, August 29, I heard of a small chestnut tree in New Jersey that bore a few burs last year and which has a dozen or more this year. If the nuts mature we hope to get some of them to propagate. Last Sunday, August 31, I saw a three inch sprout in Connecticut that had had a few burs on it. I would be glad to learn of any cases of this sort that may come to your attention.
You are all thinking men and women and all of you have had experiences with diseased trees of some sort, many of you with very serious diseases, and some of you I know have had a wide experience with the chestnut blight, so you can draw your own conclusions as to the significance of the facts that I have stated.
As to the state laws for transporting material from one state to another I am not posted, but I believe that we can be advised by writing to the government at Washington.
DR. MORRIS: We do not know whether the Washington government will sterilize those scions and send them out for us, but there should be some way of sending from one state to another.[B]
It seems to me that in all probability, the vital energy of the protoplasm of the endothia is diminishing. Quality, flavor, or anything you please, is bound up with certain vitality, and that diminishes and finally will cease. That is the reason for the endothia growing less now.
PROF. COLLINS: My point was perhaps not exactly that. I meant that the result is that, with the average cases, we are now getting chestnuts not so quickly destroyed. The explanation may be exactly what you have stated.
DR. MORRIS: There are two factors to be considered. First, the running down of the vital energy of the protoplasm; and second, in the factors which affect the vital energy of the plant.
PROF. COLLINS: In the paper I have just read there was mentioned the apparent number of trees in various parts of the country which are very slowly dying from the blight, and some which have resisted it entirely, so far; but that was not the point I desired to emphasize. There are some around New York City which are still growing, and Dr. Graves could tell us of this.
MR. O'CONNOR: Would it be desirable to take out an old tree where there are new sprouts? One tree on Mr. Littlepage's place in Maryland has a number of sprouts coming up. I suggested that if we could get people together and clean the woods up we could dig up the old trees and only leave the blight-resistant ones.
PROF. COLLINS: That is near Bell Station where we do our experimental work. We found one place infected. I cleaned it out and we have not seen anything of the disease since.