Hon. T. P. Littlepage: Mr. President: On behalf of the members of the Northern Nut Growers Association, I desire to thank the Mayor very cordially for his delightful words of welcome to this city. We feel that the words haven't any strings to them, such as were indicated in a little poem I noticed the other day, which said that a young man took his girl to an ice cream parlor and she ate and she ate and she ate until at last she gave him her heart to make room for another plate. (Laughter.) There apparently isn't anything of that in the cordial welcome which we have received here to this great County of Lancaster. I know now after hearing the Mayor's discourse upon the great resources of this county, why it was that a young fellow who had rambled out into the West and happened to drop into an old fashioned protracted meeting, when asked to come up to the mourners' bench, objected somewhat, and finally when they said, "Well, young man, you've got to be born again;" replied, "No, it isn't necessary, I was born in Lancaster County, Pennsylvania." (Laughter and applause.) I understand now why the young man was so sanguine, why it wasn't necessary to be born again, even under the auspices of the Great Spirit. It is very gratifying indeed to be in the midst of a great county of this kind that has made one of the great basic industries so successful. It takes three things to make a really great nation; it takes great natural resources, it takes great policies and it takes great people. We have nations in this world where the resources, the possibilities of agriculture and all lines of human endeavor are as unlimited, almost, as ours, but they haven't the people and in the cases where they have people of the right kind, they haven't adopted the policies. It takes those three things for any county, any state or any nation to be really great, and it is indeed gratifying to those of us who believe in the highest development, the best for humanity, to come into a county where the people, through their industry, their policies of advancement, have made that county one of the best farmed agricultural counties in the United States; and that is saying a great deal when you consider the greatness of this nation and her immense wealth and resources. It is indeed gratifying to all of us who are spending some time and some effort to further somewhat the advancement of the country along horticultural lines, to be met with a cordial welcome and to come into this community that has so highly developed her various resources: so, on behalf of this Association and all its members, even the members that are not here, those of them who might, if they desired, take advantage of the Mayor's corkscrew and carnation bowl, I thank the Mayor and thank the citizens of this County and say that we are delighted to be among you. (Applause.)
The Chairman: We will now proceed with the regular order of business. As my paper happens to be placed first on the list, through the methods of the Secretary, I will ask Mr. Littlepage to kindly take the chair while I present notes on the subject of hybridizing nut trees.
THE PRACTICAL ASPECTS OF HYBRIDIZING NUT TREES
Dr. Robert T. Morris, New York
DR. ROBERT T. MORRIS OF NEW YORK
First President of the Association, 1911 and 1912
In the experimental work of hybridizing nut trees, we soon come to learn that a number of practical points need to be acquired before successful hybridizing can be done. This is a special field in which few have taken part as yet, and consequently any notes upon the subject will add to the sum total of the knowledge which we wish to acquire as rapidly as possible. First, in collecting pollen; it is important to shake our pollen into dry paper boxes. If we try to preserve the pollen in glass or in metal, it is attacked by various mould fungi and is rapidly destroyed. We have to remember that pollen consists of live cells which have quite as active a place in the organic world as a red squirrel, and the pollen grains need to breathe quite as much as a red squirrel needs to breathe. Therefore they must not be placed in glass or metal or tightly sealed. Further, the pollen grains need to be kept cool in order to avoid attacks from the greatest enemy of all organic life, the microbes or the lower fungi. Probably we may keep pollen for a longer time than it could ordinarily be kept, if it is placed in cold storage, but practically I have tried the experiment on only one occasion. Last year I wished to cross the chinkapin with the white oak. The white oak blossoms more than a month in advance of the chinkapin in Connecticut, and the question was how we could keep the white oak pollen. Some of it was placed in paper boxes in cold storage; some in paper boxes in the cellar in a dry place. Pollen which had been kept in the cellar and pollen which had been kept in cold storage were about equally viable. It is quite remarkable to know that pollen can be kept for more than a month under any circumstances. Hybridization occurred in my chinkapins from this white oak pollen. Sometimes, where the flowering time of such trees is far apart, it is important to know how we may secure pollen of one kind for the female flowers of the other. Two methods are possible. In the first place, we may secure pollen from the northern or southern range of a species for application upon pistillate flowers at the other end of the range of that species. Another way is to collect branches carrying male flowers before the flowers have developed, place them in the ice house or in a dark, cold room without light until the proper time for forcing the flowers, and if these branches are then placed in water, the water changed frequently as when we are keeping flowers carefully, the catkins or other male flowers will develop pollen satisfactorily a long time after their natural time of furnishing pollen, when they are brought out into the light. In protecting pistillate flowers from the pollen of their own trees, with the nut tree group where pollen is wind-borne rather than insect borne, I find that the better way is to cover the pistillate flowers with paper bags, the thinner the better, the kind that we get at the grocery store. It is best to pull off the undeveloped male flowers if they happen to be on the same branch with the female flowers, and then place the bags over the female flowers at about the time when they blossom, in advance of pollination of the male flowers. It is not safe to depend upon pulling off the male flowers of an isolated tree and leaving the female flowers without bags to protect them from pollen of the same species or of allied species, for the reason that wind may carry pollen to a great distance. One of Mr. Burbank's critics—I am sorry he has so many, for they are not all honest or serious—one of his critics, in relation to the crossing of walnuts, said that it was due to no particular skill on the part of Mr. Burbank, for, whenever the wind blew from the east, he regretted to say that his entire orchard of Persian walnuts became pollinized from the California black walnuts nearly half a mile away. This is an exaggeration, because the chances are that most of the Persian walnuts were pollenized from their own pollen, but in the case of some Persian walnuts blossoming early, and developing female flowers in advance of male flowers, pollen might be carried to them from half a mile away in a high wind from California black walnut trees. Black walnut pollen would then fertilize pistillate flowers of the Persian walnut. I have found this a real danger, this danger of wind-pollination at a distance, much to my surprise. Last year I pollinized one or two lower branches of female flowers of a butternut tree which had no other butternut tree within a distance of a good many rods, so far away that I had no idea that the pollen would be carried from the tree with male flowers to the one which happened to have female flowers only that year; consequently I placed pecan pollen on the female flowers of the lower branches of this butternut tree without protecting them with bags, and left the rest of the tree unguarded. There were no male flowers on that butternut tree that year. Much to my surprise, not only my pollinized flowers but the whole tree bore a good crop of butternuts. This year, on account of the drought, many of the hickory trees bore female flowers only. I do not know that it was on account of the drought, but I have noted that after seasons of drought, trees are apt to bear flowers of one sex or the other, trees which normally bear flowers of both sexes. This year a number of hickory trees bore flowers of one sex only, and I noted that some shagbark trees which had no male flowers had fairly good crops of nuts from pollen blown from a distance from other trees. I had one pignut tree (H. Glabra) full of female flowers which contained only one male flower, so far as I could discover and which I removed. On one side of this tree was a bitternut; on the other side a shagbark. This tree bore a full crop of pignuts, (Hicoria glabra) evidently pollinized on one side by the bitternut and on the other side by the shagbark These points are made for the purpose of showing the necessity of covering the female flowers with bags in our nut tree hybridizations. We must sprinkle Persian insect powder inside the bags or insects will increase under protection. When we have placed bags over female flowers, it is necessary to mark the limb; otherwise, other nuts borne on neighboring limbs will be mistaken for the hybridized nuts unless we carefully place a mark about the limb. Copper wire twisted loosely is, I find, the best. Copper wire carrying a copper tag with the names of the trees which are crossed is best. If I mark the limb with string or with strong cord I find there are many ways for its disappearance. Early in the spring the birds like it so well that they will untie square knots in order to put it into their nests. Later in the season the squirrels will bite off these marks made with cords for no other purpose, so far as I know, except satisfying a love of mischief. Now I am not psychologist enough to state that this is the reason for the action of the red squirrel, and can only remember that when I was a boy I used to do things that the red squirrel now does. (Laughter.) Consequently, on that basis, I traced the psychology back to plain pure mischief. Red squirrels and white footed mice must be looked after with great care in our hybridized trees. If the squirrels cannot get at a nut that is surrounded by wire cloth, they will cut off the branch and allow it to fall to the ground and then manage to get it out. White footed mice will make their way through wire, and mice and squirrels will both manage to bite through wire cloth unless it is very strong in order to get at the nut. The mere fact of nuts being protected by wire cloth or in other ways seems to attract the attention of squirrels. One of my men, a Russian, said, in rather broken English, "Me try remember which nuts pollinized; no put on wire, no put on tag, no put on nothing; squirrel see that, see right straight, bite off one where you put sign for him." (Laughter.) The best way for keeping squirrels and white footed mice from ascending a tree, I find is by tacking common tin, slippery smooth tin, around the trunk of the tree and this may be left on only during the time when squirrels are likely to ascend the tree. They will begin long before the nuts are ripe. In the case of hazel nuts, I have surrounded the bushes with a wire fence or wire mesh, leaving a little opening on one side, and have placed steel traps in the opening. Now here enters a danger which one does not learn about excepting from practical experience. I went out one morning shortly after having thought of this bright idea and found two gray squirrels in the traps. They had followed their natural instinct of climbing when they got into the steel traps, and climbing wildly had broken off every single branch from those hazels which carried hybridized nuts. There wasn't one left, because the squirrels when caught had climbed into the trees and had so violently torn about with trap and chain that they had broken off every single branch with a nut on it. So many things happen in our experiments that appeal to one's sense of the ludicrous, if he has a sense of humor, that I assure you nut raising is a source of great delight to those who are fond of the drama.
The field of hybridizing nut trees offers enormous prospects. We are only just upon the margin of this field, just beginning to look into the vista. It has been done only in a limited way, so far, by crossing pollen and flowers under quite normal conditions. We may look forward to extending the range now of pollinization from knowledge based upon the experiments of Loeb and his followers in biology. They have succeeded in developing embryos from the eggs of the sea urchin, of the nereis, and of mollusks, without spermatozoa. Their work has shown that each egg is a single cell with a cell membrane and it is only necessary to destroy this cell membrane according to a definite plan to start that egg to growing. Life may be started from the egg in certain species without the presence of the other sex. This may lead us into a tremendous new field in our horticultural work. We may be able to treat germ cells with acids or other substances which destroy the cell membrane so as to allow crossing between very widely separated species and genera. Loeb, by destroying the cell membrane of the sea urchin, was enabled to cross the sea urchin with the star fish, and no one knows but we may be able, following this line of experimentation, eventually to cross the shagbark hickory with a pumpkin and get a shagbark hickory nut half the size of the pumpkin. That is all! (Applause.)