I feel we should recognize the fact that eradication of brooming disease is impossible; but one should plant, or graft, those varieties known to bear good crops in spite of this trouble. The Thomas and Grundy black walnuts do very well here, as well as the two local nuts mentioned. I do not know of any Persian varieties affected. I do not have any Persian trees with the typical broomy bunch, as is so often seen in the j.a.panese walnut, and its hybrids. The native black walnuts, when affected, seem to fail to fill properly, are immature, and watery, black veined, and worthless at harvest time, shriveling to a dark, hard, kernel when cured.
I think this answers the oft-asked question, "Why do not my black walnuts fill as they used to?" There is a strange relation to the filling of the native black walnut and the days of 1934 and 1935, when we had the great walnut caterpillar scourge!--when the trees were stripped of all their leaves. Ever since, we have had the brooming disease to contend with. One could jump to the conclusion that improper filling and this trouble were caused by a lack of certain nutrients; but seedlings in nursery rows are often affected, even where they are given every care.
At one time this spring I thought I had found a new way of "bench-grafting" walnuts. Seven grafts, on black root, were made in December, and were planted directly in a frost-proof coldframe, as lilacs can be grafted. All seven grafts made good growth, that is, over three inches, by early May, but failed later. There is only one alive today, I do not think this an impossible method, but there must be a better way of handling to give success, such as attention to shading and careful watering. One may find more on this subject in "Propagation of Trees, Shrubs, and Conifers," by Wilfrid G. Sheat.
In our greenhouse work we have used several nutrient preparations, with poor to good results. There is one that has proved quite remarkable, and may be of use to the nut grower. Our concern has been to promote greener, healthier leaves, and the product "Ra-Pid-Gro" is most outstanding. Our tests in regards to nut growing are very limited. A pan of Chinese chestnut seed mixed in pure sand was set under the greenhouse bench last winter. The seed sprouted too early to be planted out, and trees have been left inside. Since the sand had no food value, Ra-Pid-Gro was applied to the leaves, allowing the drippings to go into the sand throughout the summer. Today, the little seedlings are indeed nice. Outside, a Persian walnut had yellow-toned leaves, and Ra-Pid-Gro was applied--now the leaves are green! It is amazing how quickly yellow leaves will become green. This appears to be a very useful product.
_I believe we can have scions too dormant to graft!_ Last winter I had to make a new scion-box for storage, so copied it after the Harrington method, sinking it in the ground north of some evergreens. Scions have kept perfectly--maybe too perfectly--because they were absolutely dormant at grafting time, and have given poor success. It was rather late to save scionwood when I received an order to cut some of Mr.
Hostetter"s "Special Thomas" wood, so I cut a little extra for myself, and some wood from a little seedling Persian walnut that I wished to hasten by topworking. The buds were very much swollen that day, and the terminal buds were partly expanded. At grafting time I was quite surprised to find the wood I had cut late to be in exactly the same condition as it was the day I cut it. When grafted, every scion grew--all nine grafts made of the little Persian walnut were smaller than a lead pencil--and were _pithy_ as well! This experience is so encouraging, I hope to have most of my wood in this advanced condition another year. Absolutely dormant wood might well be brought out of storage several days before grafting, in order to get it adjusted from winter to summer conditions.
DR. MacDANIELS: I think Dr. Crane is going to talk about the bunch disease tomorrow morning and will give us some indication about the work that has been done with that.
This matter of dormancy of scions we could probably get into an argument about, but that isn"t the subject right now.
MR. CORSAN: I find that you mustn"t go cutting back much. They don"t like to be pruned. They are an open tree that grows a branch here, a branch there. They don"t get anything like the dense branches of, say, the Turkish tree hazel. They are the very opposite, and they don"t want to be pruned, and if you go pruning them, they are likely to have the witches"-broom.
MR. McDANIEL: There is another paper by Mr. Ward of Lafayette, Indiana, "The Carpathian Walnut in Indiana." The first part of it, the introduction, covers pretty much the same thing we have heard before from some of the other speakers about the Carpathian strains in this country.
The Carpathian Walnut in Indiana
W. B. WARD
Extension Horticulturist, Purdue University
West Lafayette, Indiana
The Carpathian or hardy Persian walnuts (_Juglans regia_), as grown in Indiana, are nearly all seedling trees resulting from the desire of some hobbyists to try something new. Other than a few exceptions, most of the seedling trees were planted during the period of 1934 to 1938. Credit is due to the Wisconsin Horticultural Society in offering the seedling nuts for sale and from these plantings numerous trees grew and fruited. A few test winters, with the temperature as low as minus 20 degrees F., left only those trees hardy in wood and bud. The seedling trees under observation have been fruiting for the past six to eight years, with some trees producing as much as five to six bushels of nuts per year.
The tree grows best in well drained, fertile soil and a bluegra.s.s sod.
Small amounts of nitrate fertilizer, about the same quant.i.ty used on fruit trees, have stimulated growth and no doubt have helped in the sizing up of the nuts. The tree does not do well under cultivation or mulching, as winter injury to the tree has been recorded when compared to bluegra.s.s sod. There is also a possibility that the tree will respond to applications of liquid or soluble nitrates when mixed in spray materials. Six walnut trees were sprayed with "Nu Green" on May 9th and May 28th, 1950, using the same mixture as is recommended for apples--five pounds per 100 gallons of spray mix. These trees were observed weekly, and by late August had made more growth and gave better response than trees in comparable unsprayed rows. As the walnut trees are of different varieties, no definite comparisons may be drawn, but the trees so sprayed outgrew the unsprayed plot, although both plots had received a spring application of fertilizer of equal amount.
Set of Fruit Depends on Pollination
The best yields of fruit are found on trees that have a good pollinator close by. Oftentimes the catkins of the Persians dry up, fail to shed pollen when the pistillate flowers are receptive or fail to produce staminate flowers. It was noted early this spring that the catkins on the Persians were very few. Pollen was gathered from the b.u.t.ternut (_Juglans cinerea_) for pollinating the pistillate flowers that opened early. The mid-season flowers were pollenized with black walnut (_Juglans nigra_), and the later blooms were fertilized with pollen from the heartnut (_Juglans sieboldiana cordiformis_). Many of the pistillate flowers were bagged and remained receptive for a long period.
The best set of fruit on trees this year is on trees that have either the black walnut or the heartnut near by as pollinizers. The pollen from the b.u.t.ternut seemed to dwarf the fruit size on those trees where the pistillate flowers were bagged in the Purdue planting. We have little doubt that the Persian walnut develops a preponderance of pistillate flowers and relies on pollen from kindred species for a good set of fruit.
Nut Displays Have Educational Value
The interest in the Persian walnut in Indiana has developed to the extent that several commercial fruit growers have set out small acreages. Most of the trees are seedlings from trees previously fruited, although several growers have budded or grafted the better seedlings on the native black walnut. The public has become enthused through the various displays at local and state fairs and through the state nut show now being held annually. The exhibits have brought out some very desirable seedlings, each listed under the owner"s name. Some of the seedling nuts have averaged about two inches in diameter, and 12 year old trees have produced as much as 50 pounds of cured nuts.
The largest Persian walnut tree found in Indiana is at Lafayette, it being 12 inches in diameter and possibly 40 feet high. This tree has been fruiting for the past 15 years. There are probably five or six bushels of nuts on this large tree at the present time. This tree was placed as a yard tree for its ornamental value and for the fruit.
Numerous persons have inquired about the Persian walnut as a specimen tree in their landscaping program and the demand far exceeds the supply.
As many of the elms, oaks, and some chestnuts are going out from disease troubles, the Persians may be used as a replacement. The food value of the walnut compares very favorably with that of other native nuts, according to Dr. A. S. Colby, of the University of Illinois.
----------------------------------------------------------------------- % Water % Protein % Fat % Carbo- % Ash No. Calories hydrate per Pound Persian walnut 2.8 16.7 64.4 14.8 1.3 3305 Black walnut 2.5 27.6 56.3 11.7 1.9 3105 Hickory nut 3.7 15.4 67.4 11.4 2.1 3495 Pecan 3.0 11.0 71.2 13.3 1.5 3633 -----------------------------------------------------------------------
Nut Data Important in Cla.s.sification
Three students enrolled in Horticulture have cla.s.sified several of the seedlings. Paul Bauer, 1947-48, and Edward Burns and Gilbert Whitsel, 1949-50, have been using such information for their special project work as graduate and undergraduate students. These workers found a difference in the habits and performance of the seedling trees and two such examples follow.
Nut Data Sheet
1. Common Name: _Fateley No. 1_
2. Scientific Name: _Juglans regia_
3. Source or Owner: _Nolan Fateley_ City: _Franklin_ State: _Indiana_
4. Average Size: inches 1.7x1.8
5. Average Number Per Lb.: 23
6. Average Wt. Each Nut: 15.8 _gm._
7. Sh.e.l.l Texture: _Wrinkled and furrowed_ Crackability: _Very good, thin sh.e.l.l_ Separation: _Very good_ Average Wt. Per Nut: 7.1 _gm._
8. Kernel Color: _Light tan_ Quality: _Very good, bland_ Average Wt. Per Nut: 8.7 _gm._
9. Percent Kernel: 40.5%
10. Remarks: _Exceptionally large, well formed kernel, appealing taste.
Bore 50 lb._ _1949. Tree set as 1 year seedling 1939._ (_Carpathian strain._)
Nut Data Sheet
1. Common Name: _Fateley No. 3_
2. Scientific Name: _Juglans regia_
3. Source or Owner: _Nolan Fateley_ City: _Franklin_ State: _Indiana_
4. Average Size: inches 1.3x1.54 _long_
5. Average Number Per Lb.: 34
6. Average Wt. Each Nut: 12.3 _gm._
7. Sh.e.l.l Texture: _Smoothly wrinkled_ Crackability: _Very good, paper thin sh.e.l.l_ Separation: _Very good to best_ Average Wt. Per Nut: 6.9 _gm._