3RD CONTROL OF PLANT CELL NUTRITION
With this topic we are probably less concerned in its relation to grafting than when the growing and bearing stages come. However, certain nutritional disturbances appear early and the more vigorously the stock is growing beforehand the better progress, of course, the grafts will make when they are started. Whether or not they will start more readily have I been unable to ascertain, but I have a bunch of little fellows with a growth of only an inch or so, and so puny that I cannot account for it in any other way than a lack of proper nutrition. Many of these little trees, used as stock, are very old in comparison with their size and they will probably be dwarfs all their lives. It is a question whether many such trees should be grafted at all. Further observations will have to be made to decide that point. Perhaps proper preparation for a year or two would be beneficial.
This topic will largely be left for future discussion under another subject, but it occurs to me that much might be accomplished by proper attention to nutrition, especially when setting out trees for grafting, selection of proper site, fertility of soil, cultivation to aid absorption, etc. I have observed limbs of animals much smaller than normal due to prohibited movements or lack of proper circulation, one side of a tree developed out of proportion, eggs without hard shell due to lack of calcium in the hen's diet, and I know of an old English walnut tree that bears nuts with shells so thin as to be almost negligible. I am told that at one time this tree bore a nut with a much thicker shell. It has never had any attention and it is quite probable that the lack of proper shell building elements causes the trouble. I have grafted a few of these and I want to see what happens by furnishing better nutrition.
Concerning scion wood, I have "ringed" some limbs, similar to the method used sometimes in producing extra large fruit, in an effort to have the scion store up a large amount of nutrition. This experiment I shall continue in the spring.
This article is based entirely on my own ideas, observations and conclusions in connection with old standing principles. As previously stated, I claim nothing new and my only desire is to stimulate others to make like observations.
Carrying out my conclusions in my work next spring I propose to cut the tops out of all my trees, leaving a few lower limbs instead of the top ones, allow them to start growth a little before grafting, pinch the tip from that growth, and, in addition to covering with paraffin or some combination of it, shade the scions on the south-west side, either by tipping branches over them or some other way. Paper bags seem to absorb the paraffin. Double grafting in the case of the Vest and the Weiker will be tried. Whitewashing the stock to prevent sun burn will be used where necessary. Several other experiments based on the idea of cellular stimulation before the scions are placed in position will be tried.
Dr. M. B. Waite, of the Federal Insecticide and Fungicide Board, U. S.
Department of Agriculture, spoke as follows:
DR. WAITE: Some of you may recall that several years ago, when you were meeting here in this hall, I gave you a paper on the nut diseases of the northeastern part of the United States, and it would not be desirable to go over that same ground again. At that time, we took up the bacteriosis of the Persian Walnut, and filbert blight, and I outlined a program of proposed treatment for the filbert blight. It might be interesting to note here that Dr. Morris, and I believe also Mr. Bean, put that treatment into practice with success. The situation still remains, however, that we do not know of diseased plantings of any size. If we find a real plantation of filberts we will be glad to attempt control measures ourselves. I have planted about two dozen filberts and they still remain free from the disease. There are very few local hazel nuts, wild or cultivated, around Washington; but we understand that the few hazel nuts are free from this disease.
There are two or three things I wish to mention. One is the repeated inquiries reaching my office with regard to the non-filling of nuts, mostly the cultivated nuts, sometimes the pecan, sometimes the black walnut, and frequently the English walnut. The subject is a complicated one and the disease is not one that we can put under the microscope and diagnose at once. The trouble is due to a complex of varietal and environmental conditions, the effect of the conditions of growth, of soil fertility, temperature, soil, water and humidity, sunshine, etc., on that plant. Very often it is because people get the wrong variety and do not know what they have. They may have an unproductive seedling.
On the other hand a good variety may fail to bear in a locality where it is not suited. Very frequently the real lack is in soil fertility. Of course the success of the pecan trees down South around pig pens is an old joke to you gentlemen, but there is truth in that. For good nuts there is often need for a little extra manure or fertilizer, or perhaps both. Sometimes there are rich pockets in the earth where those trees would like to grow, or rich bottom lands which will produce without manure. I think one of the best ways is to fertilize with manure, if possible. Pollination troubles in connection with the non-filling and dropping of the nuts should be thought of.
Then there is another angle to be considered, and perhaps I can express it most definitely to you by citing the example of the June drop of peaches. Whenever a tree, like the peach tree or the pecan or the black walnut, sets its fruit in the spring, you will find that there are cross-pollinated and self-pollinated fruits. These will begin to drop their nuts or their fruit at definite stages. Furthermore we will find the abortive seeds are not one size. This means that there were definite stages of the pollination and of the fertilization. I should like to work that up and find what the stages are.
The last big step in the dropping of the peach tree is the shedding of the fruit just as the pits are hardening. When they are hard the fruit does not fall. So this June-drop question ties in with the complications of pollination and nutrition. We know from experiments on the sterility of the pear tree, if highly fed and cultivated, such as those I worked on in the city of Rochester, that those highly fed trees will have some self-fertilized pears. In all of the pears we got no pears resulted when pollinized with the pollen of the same variety, except on those well fed trees. We learned this in the East, and have since found the same type of self-fertilized pear occurring naturally in California and other places in the West. In nut production that whole question of setting and filling is tied up in a complicated way with pollination and nutrition.
Aside from nutrition the other thing to be considered is that of disease. The common black walnut around Washington is generally poor from fungus leaf diseases. Those of us familiar with it around here know that they do not fruit well. This is not a good place for the common black walnut. The wild ones are nearly all poor. I was raised in the Mississippi Valley, where there were large nuts and fine ones, and we gathered those which fell from the specially good trees. They do not grow so well here, except the Stabler and a few others.
Leaving that subject, there is another I wish to take up. That is, the great number of complaints about winter-killing of the English walnut. Wherever we have been able to trace that down, as we frequently have, we find that the English walnut suffers more from winter-killing right around Washington, D. C., and in Pennsylvania, than up in Rochester; and we also have complaints of winter-killing as far south as Georgia. A common cause is the variation of moisture. After a dry spring and early summer soaking rains come in August and September, and the trees, brought suddenly into growth at the close of the season, when they should be drying out, the walnut tree in particular, show winter-killing. So I think one of the main troubles with the English walnut in the Eastern United States is the winter-killing. Even in Georgia we may have this trouble with the pecan, young trees two and three years old, and I have photographed them.
As to false stimulation, in the woods, where these trees grow native and under the conditions to which they are necessarily adapted, they are mulched and crowded when young by their competitors. In cultivation we do not get the crowding and the mulching that makes steady growth and proper ripening. So you should, by some process, growing corn, cover crops, or other trees, keep your delicate nut trees a little crowded and, if possible, mulched while young; and then later, cut out the undesirable things and let the trees have room.
I am not fully prepared to speak about the nut work of the Bureau of Plant Industry, because that should be handled by the chief of the bureau. I have charge only of the diseases of fruits and nuts. We have had $8,200 allotted to the project and will have $2,000 more this year, making $10,200. Originally that was $3,000 for nut diseases all over the United States. We started to work mainly on the southern pecan diseases, and partly on the bacteriosis of the walnuts of the United States. But the Southern Pecan Growers' Association got some additional money for the bureau, $5,000 of which was given to the fruit disease investigations, and was tied up with the other $3,000. But the wording of the bill said, "All for pecan diseases." So we transferred more to the project and made it $8,200 for the nut diseases. That means we have done very little work for the nut diseases except on Southern pecans, and I have been warned that one must not stress southern pecans with the Northern Nut Growers' Association.
We have had, however, one man, and will have two men, on the southern pecan diseases in Georgia, on pecan scab and pecan leaf diseases, who are winning out beautifully, and have nearly solved many of the problems, including the pecan scab. One of the difficulties is the occasional late summer rainy spell, bringing diseases and bad conditions. But in general we have solved the problem pretty well.
Then we have the more permanently dangerous disease, pecan rosette, which has taken about half of the pecans in some sections of the South, especially in south Georgia and in Florida. That disease is being experimented upon in the most extensive way of any of our projects. There is only one word to say about pecan rosette, and that is—humus—the disease is cured by the application of humus.
MR. REED: How far north is the walnut rosette disease?
DR. WAITE: As far as Falls Church, Va., but not much in the North.
MR. REED: The question was asked yesterday as to whether it could not be overcome in this latitude.
DR. WAITE: That nobody knows. The soils east and south of Washington are all acid, and the conditions are wrong for rosette. The soils have no tendency to chlorosis. They are, in fact, antichlorotic. Theoretically you could get the rosette conditions in the Piedmont region, but you are almost certain not to find them over this way.
Now in the organization of the Bureau of Plant Industry there are at least two main offices where nut problems would be studied; in the Division of Horticultural and Pomological Investigations and in my office, where the diseases are studied. Remember, also, that the insect pests are studied in the Bureau of Entomology; they have experimented quite extensively with pecan insect pests, and have the organization to handle such pests. Of course there is a Bureau of Markets and the Office of Soil Fertility in the Bureau of Plant Industry, which handle the pecan, incidental to the other studies.
MR. BIXBY: I would like to ask Dr. Waite a question. The association has spent a good deal of time in developing exact methods of measuring quantitatively the various characteristics of nuts which are considered valuable, and that study has given us methods of comparing notes from year to year, comparing the same nut, and I have noticed that it is quite frequent that the kind of nut that is good one year, will not be so good the next year. To take an example, the Clark hickory, which took the prize one year, the next year fell so far down that it would not take any prize. But after a good deal of trouble I found that by careful examination I could pick out from the nuts a few which tested up as they did before. It occurred to me that a condition of that kind would be more likely to be due to difference in the soil than in the fertility of the pollen. Dr. Waite has had more or less experience in noting the effect of the pollen, and I would like to ask if he thought this the cause of the difference in the nuts.
DR. WAITE: I think it might be the cause for a little difference, but we could account for the difference by entirely different things. By environment and other conditions. Take the apples grown in this vicinity; I have observed that certain seasons fit certain varieties. This year it was favorable for Ben Davis, and yet we have had a poor crop of most varieties; the conditions were bad for the Winesap to set, but yet the fruit is good. Every year and every day is different; and plants are subjected to these complications, and the yield, or the result in fruit, is a response to environment. They are so very susceptible to these things. I came here this morning after picking some cross pollenated pears on the Arlington Farm. We have a lot of crosses there where we study the hybrid seedlings. Some will be almost too poor, in certain years, to deserve further attention, and good another season. In other words, these nuts probably do not vary any more from year to year than many of our fruits and vegetables do, and the main factor is probably response to environment, namely, temperature, air humidity, soil moisture and sunshine.
THE PRESIDENT: I might mention that we have had a filbert orchard at Rochester for eleven years, and there has not been the slightest indication of blight there yet.
MR. REED: I would like to ask Senator Penny how the Roadside Bill is taken in Michigan.
SENATOR PENNY: According to the Michigan law, the people along the roadside consider that their property is subject to the right of transportation on the highway; just as a stream is owned by individuals in Michigan, subject to the right of individuals to use it. This bill says, "Give the right to plant trees on the highway," and I think the planting is done with the consent of the owner. The agricultural college has a landscape gardener connected with the landscape department; he will have charge of planting along the roadside, and I think it will be done in a scientific manner; but I believe it is necessary to get the consent of the owners first.
MR. BIXBY: Last evening Mr. Franklin Weims, of Washington, was with me on the state highway of Maryland, coming south from Baltimore. The highway is being constructed at the rate of about eight miles a year, and funds have been provided. Mr. Weims feels that something should be done to see that the new highway is properly planted with trees, preferably nut-bearing trees. I was thinking that the association might, by some resolution, bring that matter to the attention of proper authorities. I would like suggestions.
MR. CLOSE: It might not be out of order to adopt a resolution and address it to the Governor of the state, Governor Richie; and also to the State Forester, Dr. Besly, suggesting that perhaps some of the trees and seedlings might be presented to the state, some of the trees that Professor Linton spoke of this morning. Trees of that sort might carry some weight.
THE PRESIDENT: Suppose we adopt a resolution and name Professor Close to take up this matter with the proper state authorities, speaking particularly of our ability to furnish seedlings from the Mt. Vernon trees.
MR. CLOSE: If it is the wish of the association, I would be glad to do that. (Motion made, seconded and adopted).