The nuts are available in the wild from July through September and occasionally persistent on the plant until December or even February. The nuts average about 250 per pound, with a germination of about 80 percent, producing about 60 usable plants per pound of seed.
Three of the best known varieties ofC. americanaare the Rush from Pennsylvania, the Littlepage from Indiana, and the Winkler (most hardy) from Iowa. [See footnote following.—Ed.][19]
Incidentally, Thomas Jefferson in his list of plants native to Virginia, as published in hisNotes on the State of Virginia, which was written in 1781, and published in 1782, in 1784-1785, and in 1787, lists among other plants the "Hazelnut (Corylus Avellana)", which apparently should have been calledCorylus americanaWalters.
Breeding Filberts in the East.This brings up the question of filbert breeding in the East. Crane and Wood (1937) have fully reviewed the breeding program with filberts, and the breeding of filberts, for the East may be briefly referred to here. Tho pollen fromC. californicaandC. americanaapparently does not function on the pistillate flowers of European varieties, (Corylus avellanaL. andC. maxima). Since however,C. americanais useful as a pistillate parent, it is possible thatC. californicamay be similarly used.
The workers of the United States Bureau of Plant Industry are primarily testing first-generation hybrids resulting from crosses with the pistillate parents Rush,[20] Littlepage, and Winkler ofC. americanaand pollen from varieties ofC. avellananative of Europe, northern Africa, and western Asia, and ofC. maxima, the filbert of southeastern Europe and western Asia. Other pollen parents wereC. colurna, (Turkish hazel, native of southeastern Europe and western Asia) andC. heterophyllaFisch., (various leaved hazel from eastern Asia.)
Crane and Wood (1937) suggest that varieties of high merit should bedeveloped for home plantings over much of the region from lower NewEngland and Great Lakes on the north, and to the Potomac and ArkansasRivers on the south, and that much of Wisconsin, southern Minnesota,South Dakota, and Nebraska might also be included.
Dr. Crane writes, by letter dated July 27, 1948, that he has as a result of breeding work, which was started many years ago, two new varieties that have been placed in the hands of nurserymen for multiplication. These varieties are at the present time carried under the numbers of 1667 and 2336, These are hybrids between the European filbert (Corylus avellanaL.) and the native American hazelnut (C. americana.) At the Plant Industry Station at Beltsville, Maryland, these two varieties have been outstanding in their yielding ability, hardiness, and quality of nuts produced. Dr. Crane does not think, however, that these varieties may very materially change the situation as regards commercial filbert growing in the East and in the South.
Because of the conditions prevailing during the last war, nurserymen have not made as much progress, in propagating these new varieties as had been originally hoped. Dr. Crane plans to release these varieties for extensive plantings just as soon as there are sufficient plants in the hands of the nurserymen to warrant their being called to the attention of the general public.
HILLCULTURE PROJECT. The Department of Horticulture of V.P.I, has what is called a Hillculture project, with Professor R. C. Moore in charge. Among the materials planted in connection with these studies are filbert varieties to determine their possible value on hill farms in the mountainous regions of Southwest Virginia as a source of additional food and supplemental income for such families. The Forestry Division of TVA has co-operated in supplying not only propagated plants of filberts, but also of walnuts and seedlings of chestnuts.
Among the filberts now being grown are six German-named varieties from the Hillculture Division of the Soil Conservation Service, Glenn Dale, Maryland, planted as rooted cuttings in 1941. The German varieties, are as follows: (1) Barr's Spanische; (2) Neue Riesennuss; (3) Fruhe von Fruendorff; (4) Schliesserin; (5) Eckige Barelloner; and (6) Vollkugel.
In addition five varieties, including two of the Jones numbered seedlings from crosses between the American hazel and the European filbert, purchased from the J. F. Jones Nursery[21] of Lancaster, Pa., were planted in 1947. These are the following: (1) Jones 185; (2) Bixby (a Jones hybrid), (3) Cosford, (4) Italian Red; (5) Large Globe and (6) Medium Long.
Seedlings of the American hazel have also been planted. Dr. Crane may be able to send the V. P. I. Department of Horticulture a few plants of his seedlings 1667 and 2336 to include among the variety plantings.
+Some Limitations of Filbert Growing in Virginia+
DISEASES. Possibly the present most serious limitation to commercial production of filberts in Virginia is the Filbert Blight or Black Knot (Cryptosporella anomala.(PK) Sacc.). While this fungus results in little damage to native species (C. americana) it does spread rapidly and with serious results to European varieties in the State. Possibly the seriousness of the disease has been lessened by the eradication of native hazel plants on roadsides, fence rows, and in the wild nearby, which serve as hosts for the disease.
It is present on the American hazel, but does little damage to the plant. The disease, however, as mentioned, is a serious menace to either European varieties or to the present hybrids resulting fromC. americanaxC. avellana. The control to date is to prune off and burn affected parts. Mr. George Slate has mentioned that Mr. S. H. Graham of Ithaca, New York, has a number of hybrids betweenC. americanaandC. avellanathat have been subjected to severe attacks of Filbert Blight and a few of these have to date escaped, although the others have been destroyed by blight.
The bacterial blight present on the Pacific Coast apparently does not occur in the East.
INSECTS. A second limitation is the problem of the attacks of insects. Dodge and Rickett (1948) report thatCorylusmay be affected by a leaf-damage from the feeding of leaf-hoppers (Phepsins ishida;P. tinctorius), which may involve less than half the leaf or may extend to the entire leaf. The first leaves to be infested are those next to the ground, which are affected early in July. Most of the damage ceases by the first week of August. Control is by spraying with nicotine sulphate and soap on the undersides of the leaves in late June or early July, repeating at the end of a week.
Certain nut weevils (Balaninus spp.) attack the native hazels, but Slate (1930) reports they do not attack the European filbert (C. avellana). Mr. Slate reports that in Geneva where nuts are carefully picked up they do not have much of a problem with weevils.
Dr. Crane reports that the Japanese beetle severely damages the filbert. While the Japanese beetle has not yet become widely established in Virginia, it undoubtedly will eventually become a problem throughout this state. The Japanese beetle can be destroyed by using four pounds of 50% wettable DDT or two pounds of actual DDT per 100 gallons. Such sprays should be applied as the Japanese beetles begin to cause injury, and usually two applications may be sufficient.
Mr. G. F. Gravatt has reported that his filbert plantings, surrounded on three sides by woods, are badly attacked by stink bugs that sting the nuts. DDT as suggested for Japanese beetles may also be used for stink bugs.
Another serious insect pest on hazelnut is the curculio. Clean cultivation has been reported as a supplementary measure for curculio control, as they depend, upon unbroken soil in the fall for their metamorphosis. Some hybrids are reported as being relatively immune to the attacks of curculio (Weschcke, 1946). Benezene hexachloride has shown promise with other plants in curculio control and may have possibilities on the filbert.
LACK OF HARDINESS. A third limitation has been lack of hardiness in the case of European varieties. With the European varieties the staminate or the pistillate flowers or both are likely to be killed by winter temperatures. In fact, occasional unduly low winter temperatures may kill the tree tops or even the tree trunks to the ground. The Winkler variety (C. americana) has been reported as more hardy in New York State than the Barcelona (C. avellana) or the Jones hybrids (C. americanax.C. avellana) (Ross Pier Wright, 1944).
Under western New York conditions, Slate (1930) reported that the blooming period starts about March 20 to 25 at Geneva, and lasts about a month. In central Virginia this may well be several weeks earlier. Slate (1930) also reports that the flowers in bloom will withstand considerable frost, and that even with temperatures of 16°F. during the blooming season, neither female nor male flowers, may be injured. Nevertheless, with filberts coming into bloom in late February to early March, they would be subjected to temperatures that might result in injury especially to the catkins.
Some of the more hardy varieties as reported by Slate (1930) include the following: (a) White Lambert (not of value) (C. maxima); (b) Red Lambert (C. maxima); (c) Cosford; (d) Purple Aveline (C. avellana); and (e) Early Globe (of little value).
Some of the varieties upon which both the staminate and pistillate flowers tend to bloom relatively late are (a) Althaldensleber, (b) Kentish Cob, (c) Red Aveline, (d) Purple Aveline, and (e) Bolwiller. Late blooming, however, does not necessarily insure escaping injury from low spring temperatures. The Cosford, Italian Red, and Medium Long are considered by Slate as good for New York. The Bixby and Buchanan are the result of crossingC. americanaxC. avellana, and appear to be of promise for home plantings in the East. Mr. H. F. Stoke is growing the Italian Red and Du Chilly (Kentish Cob) with Daviana for pollination purposes in the Roanoke area.
CROSS-POLLINATION. A fourth limitation is the fact that varieties are nearly entirely if not fully dependent upon cross-pollinization by other inter-fertile varieties that bloom at about the same time in order to insure a set of nuts. This limitation may be overcome by the proper planning of hardy varieties are inter-fertile. Colby (1944) has reported that the Winkler variety is self-fertile.
SUCKERS. A sixth limitation is the tendency of theC. avellanaorC. maximato sprout about the base and the labor and expense of keeping these sprouts pruned out. It is possible that this factor may be overcome by using Turkish hazel (C. colurnaL.) as an understock and grafting or budding thereon the varieties that sprout when on their own roots. The Turkish hazel does not sprout as badly as the two other species.
Note by Editor: An Oregon nursery, which formerly propagated European filberts on the Turkish understock, now has abandoned its use. The grafted filbert tops did not seem to survive and bear as consistently as those on their own roots, after a period of several years in orchards.
PLANTING IN VIRGINIA. In a letter dated May 17, 1948, addressed to R. C. Moore, Assistant Horticulturist, V.P.I., H. J. Pettit, Assistant Secretary of the Planters Peanut Company, Suffolk, Virginia, reported that some years ago they planted several thousand trees of filberts, which they obtained from the states of New York and Oregon. From their experience it appears that late spring frosts destroyed the flower parts, which developed early, with the result that the yields were too low to be profitable. Hence, the filberts were removed and the land otherwise utilized. Mr. H. F. Stoke, however, in the Roanoke area has not found lack of hardiness as serious as the problems of diseases and insects of filberts.
An important nursery in Maryland has provided information to the effect that during this past 1947-48 season it sold for planting in Virginia a total of 34 filbert plants in lots of from one to ten. Its 1947-48 catalogue lists varieties of filberts for sale as follows: Barcelona, Daviana, Du Chilly, and American hazel.
Dr. H. L. Crane, Principal Horticulturist of the USDA, writes in a letter dated July 27, 1948, that he knows of no substantial plantings being made anywhere in Virginia. He has observed a few bushes or trees scattered about the homesteads, particularly in the northern or more mountainous part of the state. In most cases the performance of these filberts has not been entirely satisfactory because of leaf scorch during the summer, due apparently to high temperatures or unfavorable moisture conditions or to the winter killing of the catkins, or in some cases winter injury of the shoots. The largest plantings in Virginia that have yet come to the attention of the V.P.I. Department of Horticulture are those of Mr. Stoke in the Roanoke area.
Dr. Crane has observed the planting of a few bushes of the American hazelnut in Virginia. Their performance has been somewhat better than has been that of the European filbert, especially as to hardiness, and these American hazelnuts have borne more satisfactory crops of nuts than have the European filberts. The nuts produced by the native varieties, however, are small in size, thick shelled, and the kernels are small and lack quality. Observations by Dr. Crane, which have been made in the State of Virginia, lead him to believe that with the material that is at present available from nurserymen, there is not much hope of successful commercial filbert culture in the State of Virginia. When, however, seedlings 1667 and 2336 may become available, two varieties that are hardy and productive of fairly high quality nuts may provide material for home plantings or for local markets.
Ornamental Value.The filbert, however, also has possible value for ornamental plantings with its attractive foliage, or as a hedge, as well as for nut production, providing the home owner will control insects and diseases and maintain favorable growing conditions for our best known varieties.
Future Outlook in Virginia.With a further breeding program to combine the hardiness of the American hazel and its tolerance to Filbert Blight with some of the better qualities of the European and other species to obtain self-fertile varieties better adapted to Virginia conditions and with the better insecticides and fungicides now becoming available for insect and disease control, it may be that filbert growing in Virginia has a brighter future outlook than now appears to be true.
[Footnote 19: Tree Nuts, Acreage, Production, Farm Disposition, Value, and Utilization of Sales, 1909-45. USDA Bureau of Agr. Eco. Crop Rept. Brd.: 1-25 Oct. 1947.]
[Footnote 20: Rush, itself, is now considered a natural hybrid ofAmerican and European filberts. Many of the European varieties arederived from hybrids between +C. avellana+, +C. maxima+, and possibly otherEurasian species.—Ed.]
[Footnote 21: Now located at Erie, Ill.—Ed.]
* * * * *
President Davidson: Thank you, Dr. Overholser. We have a paper from Mr. Elliott. Mr. Elliott is not here, but we are already behind our program, so I am afraid you are going to have to have that in printed form later on.
Filberts for Food and Looks in Kentucky
N. R. ELLIOTT, Extension Landscape Specialist,Department of Horticulture,University of Kentucky
Those of us interested in the landscape phase are always thinking of as many different kinds of plants as possible that may be used to create pleasing effects. Perhaps we might be criticized for overlooking several plants that would not only assist in creating pleasing effects but at the same time produce edible fruits of good quality. In my own experience I have often recommended the use of grape vines on a trellis to create a screen and at the same time produce fruit. Also in border plantings, like the shrub border, the gooseberries and currants make attractive shrubs and in addition supply fruits. In making these suggestions for plantings one needs to depart somewhat from the usual run of plants and in most instances the homeowner has never thought of using plants for effects as well as fruits.
+Filberts Good Dual Purpose Plants+
Filberts are certainly outstanding dual purpose plants, and I feel that they have not been used nearly as much as they should be. If we think of landscape from the broad point of view, we realize that screen or border plantings make up one of the most important parts of the set-up, especially in rural parts. Practically every farm home has some unattractive view near by that needs to be screened out, either partially or entirely. This view may be caused by a lot where farm animals are kept, an old, unattractive barn, or even a gullied field. Lots where animals are kept and the barn are necessary parts of the farm operations, and the gullied field may result from neglect, but regardless of the cause for the undesirable view it can and should be screened from view from the home.
In making a screen planting, two plans are possible—one, the shrub border, and the other the hedge row, and filberts are excellent to use in either planting. Where space is at a premium, the hedge offers the best form of screen. Filberts planted two and a half feet apart and pruned in such a way as to make them have a shrub appearance will make an ideal hedge and produce lots of nuts of good quality. This hedge can be counted on to be effective up to twelve feet in height.
In the shrub border filberts are allowed to produce many stems and to grow into small trees. This is done by pruning and by using groups of two or three plants in a place, planted some five or six feet apart. Different varieties may be used for different groups, thereby producing a variation of foliage. The filberts will take their places with the well known small trees like the dogwood and the redbud, when used in this way.
Still another use for filberts in landscape work is to use them for small trees as lawn specimen plants. They have a size, shape, and foliage that makes them attractive when used in this way.
+Cross Pollination Necessary+
Our experience has been that there is need for cross pollination to get maximum yields of fruit; therefore, we suggest that different varieties be used in a planting. Barcelona, DuChilly, and the Jones Hybrids seem to us well suited for this. Of course, there are others, but our experience with varieties is limited.
When it comes to the soil for filberts, we find that a fairly rich soil that has plenty of moisture is the best. Of course, the soil must drain well because the roots of filberts seem to be very susceptible to poorly drained soil conditions. If there is a lot of sand in the soil, give the filberts more moisture and food because they are rapid growers.
So far, we have not had many complaints about filberts suffering from winter injury. This may be due to the fact that so far Kentucky is not using great quantities of these plants, or it may be due to the fact that the varieties used have been reasonably hardy. The little winter injury seen so far has been in the terminal twig growth, and removal of these twigs in the spring has not meant altering the normal shape of the plant.
I do not know whether there is any significance to it but the filberts that have been fed by using well rotted manure applied in the fall and spaded into the top four inches of soil next spring have made the best growth and produced the most fruit.
So far the filberts that we have had experience with have been free from insects and diseases. One never knows how long that condition will last.
Now, when it comes to discussing filberts as a food, all that I want to say is that at Christmas time when you buy mixed nuts you usually get a few of the filberts in the mixture. These nuts are good eating, and when the plants are grown on the home grounds everyone who has them says they are much enjoyed by all members of the family. Our experience has been that filberts yield annually and, if given reasonable care, in good amounts.
In conclusion we would like to say we feel there is not only a place for filberts in landscape work, but there is an absolute need for greater use of these plants especially in rural plantings. At present, the professional landscape artists are not inclined to recommend them as often as they could, simply because they have not been trained to think of dual purpose plants. Greater publicity as to the value of these plants would undoubtedly mean greater use of them.
* * * * *
President Davidson: We also have a paper from Mr. Reed, which is of quite a good deal of importance historically on the work of Mr. Jones. I wish you could have that. Probably you will have to read that, too.
J. F. Jones, Introducer of Many Nut Varieties
CLARENCE A. REED, Collaborator[22]
The name of J. F. Jones was once one of the best known and most highly respected in eastern nut culture. It was from Mountain Grove, Wright County, Mo., that he was first heard from in 1900, when he discovered and introduced the Rockville hican, which he named after the nearest town. It never proved of value, but that fact did not detract from the importance of being first, a habit which remained with him till his death. In 1902 he moved to Monticello, Jefferson County, Florida; five years later he moved to Jeanerette, Iberia Parish, Louisiana; and in 1912, he moved to Lancaster, Pennsylvania, where he died in January, 1928.
[Illustration]
In 1903, while at Monticello, he successfully graft-propagated the Rush Persian (English) walnut and the Weiker hickory, an intermediate form between shagbark and shellbark. Both were from Lancaster County, and he used scions sent him by J. G. Rush, of West Willow, south of Lancaster. Mr. Rush is credited with introducing the walnut bearing his name, while credit went to Mr. Jones for the Weiker hickory. Some years later, on two occasions, Mr. Jones took a visitor to the Weiker parent tree when the branches were laden with nuts so that they hung down in a manner suggestive of plums. For some reason, never explained, no other tree of the variety, so far as is known, ever bore as much as a quart of nuts, although the trees frequently flowered profusely. The variety was, however, markedly dichogamous. The parent tree, which stood in the yard of Mr. Christ LeFever of Lampeter, about two miles east of the Jones home, was blown over in a heavy gale many years ago.
Mr. Jones graft-propagated a considerable number of Hales shagbark while at Monticello, with scions that came from the original tree near Ridgewood, New Jersey. However, this variety was first propagated by Henry Hales of Ridgewood, in 1879. He also had Kirtland from Yalesville, Connecticut, but like many others since that time, both it and Hales proved to be light bearers. Other hickories may have been propagated by Mr. Jones while at Monticello but these are the only ones of which there is record. The Kirtland was first propagated in 1897.
[Footnote 22: U.S.D.A. Bureau of Plant Industry, Soils and AgriculturalEngineering, Plant Industry Station, Beltsville, Md.]
+First Carload of Grafted Pecan Trees+
When he went to Florida, there were few pecan trees of bearing age in either that State or Georgia and none to speak of in the Carolinas. The "fast" trains went no more than 30 or 35 miles an hour, and a minimum of three days was required to see even an occasional planting or a single tree. Within the next few years, nurserymen everywhere propagated their own varieties and listed them in their catalogs. Mr. Jones was discriminating and propagated only varieties that then had the best reputation, such as Schley and Stuart, and some others that have not stood the test of time. In one way, he was distinctively first; he shipped the first carload of pecan trees ever to go to one address. This was in January of 1906, when 10,000 trees were shipped to Professor H. E. Van Deman who was then establishing a 900-acre orchard near Ferriday, La. A picture of the car appeared in the American Nut Journal, published by W. N. Roper, Petersburg, Va., Vol. III, No. 50, March 1906, (Van Deman had been the first Pomologist in the Department of Agriculture, 1886 to 1892).
Mr. Ray Simpson of Vincennes, Ind., went to Mr. Jones to learn how to graft pecan trees. He offered to work without pay if Mr. Jones would teach him the art. He had graduated at Cornell in 1905, and had been inspired by John Craig, Professor of Horticulture there. Craig himself later invested somewhat heavily in pecan orchards both near Monticello and at Albany, Georgia. Mr. Simpson was taken on and proved as good a propagator as the best hand and received the same pay.
While at Monticello Mr. Jones began to feel that the region might not be the best place for pecans. Perhaps he had made a mistake. It was 300 miles to middle western Alabama, where there were the nearest native trees. A disease was appearing among many of the trees planted in the East, which was then poorly understood (rosette). Pecan wood for budding and grafting was scarce and Mr. Jones would trust no one to cut it for him. He went to the trees himself.
One man who then had an abundance of wood and who could be relied upon was B. M. Young of Morgan City, La., and Mr. Jones went to him for wood several times. Once he became confused as to the trees from which he had cut a couple of bundles, so both were thrown in the river and he went back for more. Mr. Young was greatly impressed, so much so that he remembered the incident, as we shall see.
+The Move to Louisiana+
Back in Florida Ray Simpson wished to buy and Mr. Jones wished to sell, so a deal was soon made. Mr. Jones went to Louisiana where the pecan is native and there were many large trees, probably as many as could be found in any one place in the entire South. Mr. Young knew of a group from St. Paul, Minnesota, who were about to buy and plant a thousand acres near Jeanerette and who were looking for an experienced man to take charge. Mr. Jones was recommended and was soon at work. For another five years, he worked harder than almost any other white man in the State. Great odds were against him. Being from the North, he did not associate exclusively with whites, and presently the southern white people left him severely alone. That was not all; he could not raise as good nursery trees as he had in Florida. The trees grew slowly in the cold, heavy soil of Louisiana, and the fibrous root system failed to materialize. The excellent reputation he and his trees had enjoyed in Monticello began to deteriorate. He worked harder than ever and waited for a break. When it came, he did not hesitate.
+Jones Shifts to Pennsylvania+
The St. Paul crowd fell into a squabble and divided into two factions, each wishing control. A man went south to see if Mr. Jones would sell his stock. Would he? He knew when to keep his mouth shut and he meekly made a deal. He was probably never more glad over anything in his life. He came north, lock, stock, and barrel. But he was far from being without a place to land. Since his Monticello days, he and Mr. Rush had been good friends. Mr. Rush knew a farm of 20 acres with buildings, which could be had for $8,000. It was four miles south of Lancaster, and at a point where two main highways leading into the city came together. It sloped eastward enough so that it did not get the full force of west winds. It was two miles from Mr. Rush's home, with the town of Willow Street between.
Mr. Jones then began eight or 10 years of lean hard work. He modernized buildings, planted an orchard of nut varieties most of which were purchased from W. C. Reed of Vincennes, Ind., and W. N. Roper of Petersburg, Va. From Roper he bought both seedling and grafted trees. Some of the "seedlings" had been budded and then not cut back to force the buds. The latter were still dormant and when the trees were properly cut back, the buds pushed forth. T. P. Littlepage, of Washington, and Prof. W. N. Hutt, of Raleigh, N. C., had a good laugh at Roper, but as the trees bore no labels, they were no more valuable than seedlings and were treated as such. All three men are now deceased.
Thomas black walnut trees came from E. A. Riehl, Godfrey, Illinois. The variety had originated in eastern Pennsylvania and was first grafted in 1881 by J. W. Thomas and Son, at King of Prussia, Pa. The parent tree had been destroyed some time before by the Pennsylvania Railroad, in extending its lines. The Thomas is today the most widely planted variety, although it has rarely borne well. Mr. Jones selected and grafted the Ohio walnut, but the owner of the seed-parent tree was given credit for its introduction, although she probably knows nothing of the incident, to this day. She was a Miss Clark, McCutcheonville, Ohio, and it was felt that it would help more to give her name as originator if one were ever to locate the tree.
[See Ohio black walnut original tree photos, NNGA Rept., 1946.—Ed.]
The Stabler eastern black walnut, introduced in 1916 by Mr. T. P. Littlepage by means of a paragraph inserted in theCountry Gentleman, was also propagated by Mr. Jones, but he early found it disappointing in its habits of bearing. He also found that about 80 percent of the nuts from the parent tree had single kernels, while with young trees 80 percent had double kernels. Most planters have long since discontinued using this variety. However, Mrs. Jane Baum, Douglassville, Pa., reports that her customers like the Stabler best. Others she has are Thomas, Ohio, and Ten Eyck.
Other varieties were tested by Mr. Jones, but he pushed none of them, rightly thinking that 4 leaders were as many as a nursery could afford to carry. He insisted that a new variety would have to prove its superiority before he would insert it in his catalog. Among other varieties was the Peanut from southern Ohio, the nut of which had single lobes; but apparently there was some mistake along the line, as nuts from grafted trees were indifferent and had 2 half kernels. He also had Creitz from Indiana, which Mr. H. F. Stoke, 1436 Watts Avenue, Roanoke, Va., thinks well of at this time. It was a prize winner in the 1926 contest of the NNGA. Neither Creitz nor Peanut was a Jones introduction.
+His Work with Hickories+
Among the hickories, there was the Stanley from Indiana in 1916, which was quite a favorite with Mr. Jones for some time. But did any one ever see a shellbark that bore well and filled the nuts? Shellbark trees are beautiful to look at, have enormous leaves, seven to nine leaflets, but they leaf out early in spring and the flowers are frequently killed back by spring frosts. Part of its flowers are killed outright with too great frequency for it to be worth growing for the nuts. These are very large, the hulls split entirely to the base, and what kernel there is, is of sugar-like sweetness. The shells are mostly thick and the kernels seldom well-filled.
The Glover shagbark hickory, from Connecticut, which was introduced by Mr. Jones in 1918, is undoubtedly one of the best shagbarks yet propagated. The nuts are of medium size and shell thickness. The flavor is very good. Most shagbarks have five leaflets; this one has seven quite as often, and the leaf is about a foot long.
There were other hybrids, or what are supposed to be hybrids. The Pleas hickory, introduced in 1916, was perhaps first successfully grafted by Mr. Jones, but credit for introduction went to the owner of the parent tree, Dr. E. Pleas, Collinsville, Oklahoma. It was a beautiful tree, shapely, with an air of considerable refinement, making it a graceful lawn tree. It bore fairly well, although not heavily. The nuts were thin-shelled and also had thin hulls that split entirely to the base. So far as most laymen are concerned, the Pleas may be but an edible, or semi-edible bitternut. On the grounds of the Plant Industry Station, at Beltsville, Md., there were once two trees of Pleas, but they were given to the Wild Life Service for planting 10 miles away, although there are many native bitternut trees just over the line fence in neighboring woods. We fancied that we could detect bitternut flavor in good shagbarks about the plantings, due to xenia influence, as in the case of chestnuts.
Burlington was another hican first propagated by Mr. Jones, in 1915. It came from eastern Iowa, and for a time was confused with Marquardt, which never was propagated, or apparently not. Burlington makes a fine appearing tree and serves well for ornamental purposes. It bears fairly well while young, but soon develops faulty nuts, few being well-filled and the majority weevil infested. It is also subject to shuck-worm and twig girdler injury.
Mr. Jones once wrote that he had given up with the hickories "in disgust." So far as is known, he never used any stock for hickories other than pecan, which grew well, made good unions and generally outgrew the scions. John Hershey, however, says this is not a good combination, but there are too many trees of Jones' propagation about the country, to accept Hershey's verdict altogether. Carl Weschcke[23], of St. Paul, uses bitternut largely or entirely; if it is a mistake, it will be expensive. Hickories are slow to grow and one gets too few nuts at best. It takes a lifetime to get even small crops, and for our part, we want no bitternuts on the place. Too often shagbarks fail to unite with bitternut and frequently they are short-lived.
In 1916 Mr. Jones propagated and introduced the Beaver hickory, from central Pennsylvania, a supposed bitternut-shagbark cross. It proved of little value and soon disappeared. The Fairbanks from northeast Iowa, a similar cross, was introduced the same year. It was one of the prettiest of all hybrids and stood up about the longest, but it had too much bitterness in the pellicle encasing the kernel and was much subject to weevil injury.
+Efforts with Persian Walnuts+
Many varieties of Persian (English) walnut were propagated and brought into bearing. Mr. Jones included a majority of the varieties brought into the country from France by Felix Gillet, of Nevada City, Calif., as early as 1870. There were Franquette, Mayette, Meylan, Parisienne, and a cutleaf variety which appears to have had no other name. A California variety of which he thought well for a number of years was Eureka, a western introduction of 1908. He propagated a number of eastern varieties such as Lancaster (Alpine) in 1913, although credit went to Mr. Rush; Boston, from Massachusetts, also in 1913; Ontario, from Canada, in 1914; and probably others. He obtained Chinese walnuts, from P. Wang, Kinsan Arboretum, Shanghai, and sold seedlings at wholesale. These were an Asiatic form ofJuglans regia. He limed the soil, and thought the effects were beneficial. In this he was warmly supported by T. P. Littlepage and more recently by growers in Northern Ohio; but lately liming has not been found beneficial in Italy. All in all, however, the Persian walnut was not particularly dependable, and during the last few years the nursery which he left discontinued selling Persian walnut trees. In the East, the trees of older varieties usually were little more than interesting novelties.
+He Tried the Chinese Chestnut+
The Chinese chestnut was tried for a few years; but as so often happens with this species, nursery trees died badly in winter and Mr. Jones thought it due to blight, a disease which was then sweeping his part of the country, taking its mortal toll of both American and European species. However, blight does not seriously attack young trees and it is more likely that death was caused by a combination of summer drouth and winter cold; but no matter, the trees perished and the result was the same.
+First Heartnut Grafts+
Mr. Jones tried the butternut and there is still one tree in the experimental planting east of the residence. It is Aiken, from New England, and was first propagated by him in 1918. It proved disappointing. He grafted the first heartnut ever grafted of any kind insofar as is known, the Lancaster, in 1918. The only other heartnut for which he received full credit for first propagation was Faust, obtained from a dentist, Dr. 0. D. Faust, Bamberg, S. C., in 1918. Others that he was doubtless first to propagate, but for which credit went to the owners of the parent trees, were Bates and Stranger in 1919, both from R. Bates, Jackson, Aiken County, S. C., and Ritchie, a Virginia variety found by John W. Ritchie of Flemington, N. J., in 1918.
However, heartnuts are seldom heavy bearers and the trees do not grow large or live long. In Japan the wood is sometimes used for gunstocks but only because better material is unavailable. Heartnuts have practically no market where other kinds of nuts can be had and the trees are much subject to "bunch" disease. To an enormous extent the trees have been sold to unsuspecting people of the South and East as "English" walnuts.
[Footnote 23: See Weschcke's paper, elsewhere in this report.—Ed.]
+The Filbert+
Mr. Jones had a tree or two of the Turkish filbert, a species sometimes reaching a height of 60 feet and attaining a trunk diameter of three feet or more. Bixby found the species hardy in central New Hampshire. Mr. Jones obtained his seed from three trees in Highland Park, Rochester, New York, which are believed to be the oldest in the country. In some years, the Rochester trees bear freely, while in others there is not a nut. This is a valuable ornamental species, as it is green from early spring till the last thing in fall; specimens must be selected for such use, as often the trees are unshapely. Like all filberts, they are subject to Japanese beetle attack and must be sprayed or otherwise protected in beetle infested zones. Filbert foliage may be destroyed by these insects as many as three times in a summer and the trees die down to the ground. The nuts are too small to be of value; but the wood is white, very hard, and makes good turned articles.
+His Greatest Contribution+
It was with the filbert that Mr. Jones made his greatest contribution to nut culture. In 1917 he tried crossing European varieties with pollen of the native Rush. There were no results, and he tried again in 1918 with no better luck. In 1919 he reversed the order of crossing and nearly every nut set. He had discovered that native pollen was not effective on European stigmas, but that the reciprocal cross worked. By 1924 he had a fine lot of fruiting plants. The great majority were of no value, but his No. 200 apparently was well worth while. It was named Bixby in 1937, four years after another seedling, No. 91, had been named Buchanan. The explanation of this belated selection is that the soil about the Bixby tree had so eroded that the tree was starved for a time; but with a couple of years of heavy application of stable manure, it came back, so much so that it is now considered the better of the two. Both are rather small as compared with the large filberts of the Pacific Northwest; but when fully mature, they are sweet and agreeable.
After Mr. Jones was gone, the place was managed by his daughter, Miss Mildred Jones. She kept plants of her father's filbert varieties and the best of the crosses. The latter are now called the Mildred filberts, a name applied inStandardized Plant Namesto the entire group of crosses between Rush American and any European filbert. Mr. Jones hoped to have these called after himself but there was an old variety of Jones "hazel" and so his own name could not be used. He once sent specimens to Dr. C. S. Sargent of Arnold Arboretum and somehow gained the impression that the name Jones was given to the cross. Later, however, Sargent's successor, Mr. Alfred Rehder wrote that Sargent had not used the name in either correspondence or on specimens placed in the herbarium.
The example of Mr. Jones in breeding filberts has since been followed by others, as the Department of Agriculture, the New York State Agricultural Experiment Station at Geneva, and. Mr. Carl Weschcke of St. Paul, Minnesota. The last has copyrighted his crosses under the designation "hazilbert," which is a good name; but with the issue ofStandardized Plant Namesin 1942, the name "hazel" was dropped for all members of the family. For a time, an effort was made to distinguish between the two by calling small-fruited ones "hazels" and those with large fruits "filberts," but there is not exact dividing line and so now all are called filberts.
Buchanan and Bixby are the only varieties of Mildred filberts thus far fully released by anyone and although neither variety is entirely hardy in the northernmost parts of the country, they do well as far south as eastern Tennessee. The nuts of both are too small to compete in the market with the large filberts of Oregon and Washington, but that is not the purpose for which they have been bred. It is for home planting, a use for which they are admirably adapted. Neither variety should be judged until after they have cured fully, at least a month or more. Then the flavor is excellent.
Of the various introductions made by Mr. Jones, the ones most likely to endure are the Ohio black walnut, the Glover shagbark hickory, and the Mildred filberts. The first has already lasted 32 years; the second 30 years; and the Mildred filberts are only nicely started.[24]
[Footnote 24: Except for the last two paragraphs, this paper was read and approved by Miss Mildred Jones in Pavilion, N. Y., on September 2, 1948. The following day, or September 3, she became Mrs. Wesley Langdoc, of P. O. Box 126, Erie, Illinois.]
+Mr. Reed Comments on Seedling Trees+
+Editor's Note:+ The next two paragraphs should be read in connection with the "Round Table" on chestnut problems, elsewhere in this volume.
In a broad sense, it must be remembered that every variety of seedling tree, of any species and every hybrid form that has ever been planted, or grafted on another tree, has been worth something. This is still a free country and every man has the inalienable right to plant whatever he pleases. Even the hybrids of various forms, hickory, walnut, and chestnut, are all worth something. All are trees and it is better to plant a poor kind of tree than not to plant anything, particularly if it is a nut tree. Whatever prompts a man to plant a tree is worth while.
Hybrid chestnuts bred by crossing Chinese chestnuts of unknown performance record as to habit of bearing, size or flavor of nut, shape of tree, resistance to blight, or spring freezes, and other characteristics which combine to make good nuts, with the inferior and largely inedible Japanese chestnuts, are unlikely to do the damage to the industry that is sometimes predicted. They are now so mixed up that few will be planted by themselves, and there is considerable evidence that the xenia influence of good Chinese chestnuts with which the trees are being planted will render nuts from these hybrid trees fit to market and eat.
[Illustration: MILDRED AND WESLEY LANGDOC]
President Davidson: The value of nut trees in Tennessee, then, will be discussed by Mr. F. S. Chance of the Tennessee Agricultural Experiment Station in Knoxville.
The Value of Nut Trees in Tennessee
F. S. CHANCE, Vice-Director, Tennessee Agricultural Experiment Station,Knoxville, Tennessee.
Mr. Chance: Mr. President, ladies and gentlemen: As a representative of the Agricultural Experiment Station of the University of Tennessee I want to say it is a great honor to have this distinguished group meet here in Tennessee, especially on the banks of beautiful Norris Lake, which is one of the tributaries to the dammedest river in the country. We are something like 600 miles from the Gilbertsville Dam, or Kentucky Dam near Paducah, Kentucky, and this area here is the beginning of a chain of lakes that run just about that far.
For those of you who are from a distance, you may know that in making a chain of lakes out of this great Tennessee Valley that we covered up lots of good land. We have developed lots of good power. Now, I am not just sure why I was put on this program, because, really I am not a nut tree specialist, as I see most of you people are. I will admit that I have been associating with experimentation for the last eight or ten years and have become slightly nutty, but really my big interest is timber. I am still a blockhead. So in discussing and talking with you this morning for a few minutes about the value of nut trees in Tennessee I want you to just keep in the back of your minds that the thing in the timber world that I think is the prettiest when it comes to furniture is black walnut.
So in some plantings that we made several years ago with the help of Spencer Chase at our various substations and at the parent station at Knoxville, when we began to prune those trees I wanted to go to pruning for timber and he wanted to go to pruning for nuts. He won. So as we developed these plantings we are sure that we are going to have some very excellent nut trees.
Tennessee ranging in altitude from something over a mile high down to some 300 or 350 feet at Memphis on the Mississippi gives us a very, very wide range of climate. This wide range of climate gives us the possibility of growing a very wide range of timber trees. A great part of that area is soil from a limestone formation. Nearly all parts of Tennessee are well adapted to the production of the black walnut. The tree as a nut tree has not in the past been looked at with such great interest. However, there are farms in Tennessee that have been purchased with walnut kernels. Over the period of years, why, thrifty families, especially in Eastern Tennessee sections, have gathered up the walnuts in the neighborhood round about, cracked them and sold the kernels and from year to year made certain accumulations of that kind, funds, and saved them with enough in the bank or in the sock to buy a farm. I knew one particular person who bought a nice farm in just that way.
Now, a great many of the people in the same neighborhood did not save their walnuts. These walnuts were gathered from everybody's trees without any objection on the part of anyone. But it was a means of those people getting ahead with their savings from their other farming operations, and this wintertime work that they could put in, why, that kind of thrift is the kind that gets people ahead who want to get ahead and have vision.
I might say a few words about pecans in Tennessee. We have throughout the state quite a few scattered native pecans that are used, especially in all except the more western sections of the state. As a whole they are for home use. Now, in the extreme western section of the state we have a certain amount of seedling pecans, mostly, that produce a considerable income to a limited number of people. In the 1945 census something over 4,000 farms reported some income from pecans—this was mostly in the western section of the state—the value of which was something over $32,000, which at the present time would be a considerable under-valuation.
This tree is found, I might say, throughout the state. I recall a few years ago coming off of the Cumberland Plateau down in Warren County into the cove there around Viola and seeing a beautiful grove of pecans along a stream. I hadn't been through that country before, but I had known a family that lived there, and I stopped at a house to see just what those pecans meant. And there was an old lady on the porch who owned the property, and I asked her some questions about it, and she told me how they got there and knew when they were not there. She had been raised on that place but she said, "I want to show you something." So I went with her around the side yard into the back yard, and she had a couple of pecan trees there that were loaded with pecans until the limbs were hanging over just like pear tree limbs, heavily loaded pear tree limbs. I said, "My, what a crop of pecans you have here. That's really wonderful." Those were the budded pecans, the type that is grown farther south of us. She said, "Just wait a minute, now. I don't know whether I have any pecans or not." I said, "What do you mean?" She said, "If the frost is two weeks later than usual we will have a wonderful pecan crop, if we have a late frost. If we have an early frost we don't have any pecans."
It was quite interesting to me to see that wonderful crop hanging on the tree and yet she wasn't at all assured that anything of value would come from it.
We have on some of our holdings at the University experimental Stations some wonderful Chinese chestnut trees. I can't get overly excited over them, remembering the chestnut as we had it once in Tennessee with the long, slender body, wonderful telephone poles and wonderful timber of other kinds, and to see that a tremendous economic loss has come to this country through disease that was and probably is not controllable. But from the nut standpoint we have at the present time some trees that look as though they are going to be the equal of our own native chestnut that covered Tennessee from the mountain top to the river bank. So we are very much in hope that again Tennessee will have a supply of chestnuts which will be equivalent, probably, to the harvest of chestnuts we once had. However, that's going to be many, many years off.
From the experimental standpoint I have been very much interested in the timber type of tree, hoping that our native chestnut trees, at least one out of the billions, maybe would prove to be resistant. However, watching these growths come up from time to time and attain an age sufficient to produce nuts and then have my hopes blighted by going back the next year and finding that the tree was blighted has become rather discouraging. I hope that some of you people will find just such a tree, one that will bear an excellent nut and at the same time produce excellent timber.
Now I am coming to our big asset in the way of nut trees in Tennessee, as I see it. I was rather interested here in Professor Moore's discussion of the honeylocust, that detestable tree which was such a thorn in my flesh as a child, and having heard someone championing it with such a story as he had, I have heard everything now. Everybody, though, has a champion. Even my mother loved me, regardless.
Black walnut is, as I said in the beginning, native to all sections of the state, and I think that through the collection of the better yielding or better cracking nuts by the Tennessee Valley Authority we are going to find in this crop a very potent asset to the state of Tennessee through the income from sale of nuts. We have in the state about four cracking plants. One of them is located in Morristown. Down in the basin part of the state where walnuts do particularly well, three others are in the city of Nashville. There were something like 10 million pounds of walnuts in the shell delivered in Nashville this last year, yielding about 1,200,000 pounds of kernels. Now, this is no mean return from a crop which was really just gathered up with very, very little attention given to the planting. It is just one of these free crops, so to speak.
If we were to add to that income the great income which we have been receiving through the years from the sale of timber trees, we would run the value of the black walnut into considerable proportions, with income from the sale of black walnuts in the kernel and in timber.
I see no particular reason why that crop cannot be increased ten, twenty or a hundred fold by just a stimulation of interest in the black walnut. I recall back just previous to World War I, or about that time, there was a tremendous demand, as usual, for black walnut for gun stocks. I happened to be free for a month or so at that time so I could give some attention to the purchasing and delivery of both veneer stock and walnut for gun stocks. It was quite interesting to me as I went over a couple of counties in which I made some purchases, to see that someone in the 40, 50 or 60 years back had had a vision of what the walnut tree would be worth to them on their tracts of land and how we were at that time reaping the harvest of the person who had a vision of the value of the walnut tree. A great many of those trees were trees that had been set or walnuts that had been planted years before by some far-seeing person, and it had gone on without any interruption, probably without the slightest bit of protection, until the time that it was needed and desperately needed for economic purposes.
We have some work going on also in connection with the planting of walnuts in pasture fields. The returnsfrom the pasturein the planting of walnut trees have been just practically the same, maybe a little bit better in favor of the walnuts than where we did not have walnuts in the pasture. This work is being conducted down at the Middle Tennessee Agricultural Experiment Station of the University of Tennessee at Columbia. We are using the walnut tree and also the black locust in this experiment. We don't know what the future of it is going to be, but those walnut trees have grown large enough so that they have had to be thinned to keep them from putting too much shade over the ground.
I made a statement several years ago in the presence of quite a distinguished agronomist or horticulturist that I had never seen a walnut tree growing in the open, whether it was in the blue grass region or outside of a blue grass region that did not have blue grass growing under it. He looked at me askance, and I said, "Do you believe it?" "Well, I don't know," he answered.
So we happened to be coming out of Quincy, Florida, up through southern Georgia outside of the blue grass region, and we were both sitting in the back seat of the car. Our driver drove up to a filling station, and I saw this fellow looked up at a walnut tree over in the yard not very far away, in fact, the next yard to the filling station. I somehow or other sensed what he was thinking. He pushed his door open, got out. I pushed my door open, went around the car and followed him. He walked up to that walnut tree, turned around and said, "Well, it's there." He turned around and walked back.
Now, of course, a condition may prevail in dense shade, where that does not happen in young walnut trees, but I just happened to be right. There is a symbiotic relationship between plants—I don't want to get into that subject—but this one thing I am thinking, and that is that the reason why they were able to get this good grazing from under these walnut trees is that there is a relationship there between those two plants that makes it ideal for the production of pasture grass, and blue grass over a great many of our states is our leading grass.
I might say to the gentleman from Virginia that I had a letter from up there a few days ago. I don't know why they wanted to write to me, wanting to know if the walnut tree wasa legume. So I presume that that was the reason, that the grass grew very nicely under those trees.
I have taken too much of your valuable time. It certainly has been a pleasure and an honor to be here and talk to you these few minutes. Thank you.
* * * * *
President Davidson: Thank you, Mr. Chance. We will take a short recess.
(Recess taken.)
President Davidson: The meeting will now come to order, please. The embryo development of the black walnut will be illustrated and discussed by Dr. L. H. MacDaniels of Cornell University.
(Paper to appear in next volume.)
Dr. Crane: I was very glad Dr. MacDaniels' paper preceded mine, because it does give you a very much better picture of the development of all of our oily nuts, excepting the filbert and, of course, the almond to some extent. But we take in pecans and the hickories and for the walnuts the situation is quite general.
Now, this paper that I am going to read is one that our staff in nut investigations has been working on for the past twenty or more years, and we feel we know a lot about the growing and the development and filling of nuts. And there is a lot in this paper that I think will be of value to all nut growers regardless of the kind of nuts that we are trying to grow.
The Development and Filling of Nuts
H. L. CRANE, Principal Horticulturist, United States Department ofAgriculture, Agricultural Research Administration, Bureau of PlantIndustry, Soils, and Agricultural Engineering, Division of Fruit andVegetable Crops and Diseases.
All nut growers are confronted with the problems involved in the production of nuts of large size with well filled kernels that are "bright" or light colored. Unsatisfactory development and filling of the kernels is more often a cause of complaint by growers than any other single factor affecting nut production. This is because all of our commercial nuts now sold in the shell are priced on a basis of size and the degree to which they are filled. The size and degree of filling of the nuts varies not only from year to year, but from district to district, orchard to orchard, and even in the same orchard, because nuts of one variety may fill well and those of another poorly. This is true even though the kind and variety of nut being produced is grown in a locality usually having suitable climatic conditions for normal nut production.
+Climatic Conditions+
Prevailing climatic conditions in any locality determine how well a particular kind of nut will fill. For example, the pecan is native to the southern part of the United States and a small area in northern Mexico. In its native habitat the summers are long and the day and night temperatures are uniformly high, with little difference between maximum and minimum daily temperatures. When the pecan is grown under conditions of shorter summers, or where there is a marked difference between night and day temperatures, the nuts do not grow to proper size and the kernels fill poorly, if at all. Although pecan trees are quite hardy and may be grown successfully well north of their native limits, the normal development of the nuts and the filling of them cannot be expected there.
Good examples of the climactic effects can be cited. At Davis, California, the pecan tree grows, flowers, and sets fruit satisfactorily, but the nuts fail to grow to proper size, fill poorly, and may not mature before frost. At Davis there is an average length of growing season of 242 days; the day temperatures are high, but the night temperatures are comparatively low. Pecan trees are hardy even in Connecticut, but the trees fail to bear because of the short growing season and the great difference between day and night temperatures. The pecan is truly a hot weather crop and is not suited for culture under mountainous conditions. On the other hand it cannot be grown under subtropical conditions because of insufficient cold during the winter to meet the chilling requirement of the trees. Under such conditions, tree growth starts very late in the spring, and, although the trees may flower, few nuts may set and those that stick may be very poorly filled at harvest if they mature.
The pecan is probably more exacting in regard to its climactic requirements than are our other kinds of nuts, but the filbert or hazlenut is probably a close second in this respect. The filbert, however, represents the opposite extreme in that it does best under conditions of mild winter and moderate summer temperatures. These differences are pointed out for the reason that many amateur nut growers want to grow certain nuts outside of their native range in places where unsuitable climatic conditions prevail, and they cannot understand why success is not possible.
+Growth and Fruiting Habit of Nut Trees+
Since the growth and fruiting habits of our different kinds of nut trees are closely related, it is desirable to point out some of these relationships. All of our different species of walnuts, the pecan and all hickory nuts, as well as hazelnuts and filberts, are borne terminally on shoots of the current season. In other words all walnut species, pecan, and all hickory species bear the pistillate flowers that develop into nuts at the terminal end of the shoots produced the same year that the nuts mature. The staminate or pollen-producing flowers of all these species arise from lateral buds on shoots that grew the previous year. In the case of hazelnut and filbert the pistillate flowers are borne in lateral buds on shoots of the previous season, as are also the staminate flowers or catkins. In this case, however, the pistillate flowers are formed and pollinated before the current year's shoot growth is made. Almonds are borne laterally on shoots produced the previous season. All chestnuts are borne laterally on shoots produced the same season as the nuts.
The chestnut bears most of the staminate flowers separately in staminate catkins whereas the pistillate flowers are in mixed catkins, but all are formed laterally on shoots of the current season. The almond, which has perfect flowers, produces these in lateral buds on shoots of the previous year. Both the hazelnut and the almond flower before any current-season growth is made, whereas all of the other kinds of nut trees mentioned produce almost all normal shoot growth before flowering occurs. These differences in growth, flowering, and fruiting habits provide a basis for the explanation of why growth of almond trees, for example, is harder to maintain than is that of walnut or pecan. Flowering and early development of the fruit before shoot growth is made tend to check such growth, so that flowering and fruiting trees will not make as much new growth as they would have made had flowering and fruiting been prevented.
In general, it can be stated that, in the case of bearing trees, the longer the shoot growth and the greater its diameter in proportion to length, the greater is the number of pistillate flowers that may be formed at its terminal. Furthermore, the set of nuts and the size that they attain are in proportion to the length and diameter of the shoots bearing them. In other words, the number of flowers formed, the nuts set, and the size that they attain are directly correlated with the vigor and growth of the trees. As trees attain age, fewer long, strong shoots and more short, weak shoots are formed. Hence the average size of the nuts produced decreases because of the reduction in average shoot growth. Furthermore, under normal conditions, the degree to which the nuts are filled is related to the vigor as it is measured by the length and diameter of the shoots bearing them. Strong, vigorous shoots usually produce the best filled and earliest maturing nuts.
+What Is a Nut and of What Does It Consist?+
Webster gives a general definition of a nut as "a fruit consisting of a kernel or seed enclosed in a hard woody or leathery shell that does not open when ripe, as in the hazel, beech, oak, chestnut." Technically speaking, it is a hard, indehiscent, one-seeded dry fruit resulting from a compound ovary. In horticultural language the fruit consists of the hard or leathery nut containing a kernel, together with the husk, hull, or bur that surrounds the nut shell. This kernel consists of the embryo plus the endosperm or its remains. In all of our important nuts, such as walnuts, pecans, hickory nuts, almonds, and filberts, the kernel is essentially the embryo with its thickened cotyledons or seed leaves, as the endosperm has been absorbed except for a thin membrane.
At the beginning of its development, growth of the embryo is slow, and in very early stages it is merely a rounded mass of cells. Later, the meristems of the epicotyl (stem or top) and root axis develop, but the whole embryo is still microscopic in size. Still later the cotyledons (seed leaves) start development from the apical meristem and their growth in length is rapid, but they are very thin and follow the contours of the seed coat. Growth in length of the cotyledons may be arrested by unfavorable nutritional conditions during the time of elongation. In such case, the lobes of the cotyledons may not attain the full length of the seed coat, or pellicle, which surrounds them. After the cotyledons have attained full length, growth in thickness begins in the area nearest the epicotyl and proceeds toward the margins. This growth in thickness results from cambium-like meristem with the formation of new cells. The formation of well developed or solid kernels that completely fill the cavity within the shell is dependent upon meristematic activity continuing almost to maturity. The weather conditions, the nutrition of the tree, or other factors that affect the synthesis and translocation of elaborated food materials from the leaves and shoots to the kernels at this time determine the degree to which the cotyledons are thickened, or in other words how well the nuts are filled.
+Periods of Development+
In the development of the nuts there are three periods or stages: (1) The period of growth in size; (2) the period of nut filling or development of the kernel; (3) the period of maturing.
What takes place during these periods of development determines the size the nuts attain, the degree to which they are filled, and finally the quality at harvest. These three developmental stages are interdependent, because the size of the nuts may affect the degree of filling, and that, in turn, the time and nature of their maturity. They are not entirely separate and distinct but overlap in that there is more or less development of the kernel, varying with the species, while the nuts are growing in size. In general, however, there is not appreciable kernel development until after the nuts have attained approximately full size, except in the chestnut.
The outstanding example of this situation is the pecan. There is practically no growth of the kernel until after the shell of the nut has started to become hard. At that time growth of the embryo, which constitutes the kernel, become rapid. The major portion of the kernel is formed during a period of approximately one month, starting at Beltsville, Maryland about the middle of September. The final stages of filling occur just before the nuts mature, and the first nuts to fall usually have the best filled kernels. Later maturing nuts are generally poorly filled; their shells and kernels are often discolored, and the shucks fail to open properly, if at all.
The development of walnuts, hickory nuts, and filberts, so far as is known, is in all essentials the same as that described for the pecan nut except that the kernel or embryo begins to grow somewhat earlier in the season. However, the major portion of the filling, which consists in the thickening of the cotyledons, takes place late in the season, and only a month or a little more before the nuts mature.
The period of the maturing of the nuts generally closely follows the completion of the filling of the kernels. During this period in the pecan, certain other species of hickory, the Persian walnut, chestnut, and others, food reserves are transferred from shucks, hulls, or burs to the nuts. Abscission layers are formed and shucks, hulls, or burs split open on drying out, thus partially or wholly releasing the nuts. There is a very direct relationship between the degree to which the nuts are filled and their time of and normality of maturing; well filled nuts mature early and normally, whereas poorly filled nuts mature late, if at all, and shucks, hulls, or burs fail to open properly.
+Growth in Size+
The size of the nuts produced by a tree is determined by a number of factors, one or all of which may operate during the course of the season. These are: (1) Age of tree; (2) position of the nuts on the tree; (3) fertility of the soil and moisture supply, or the nutritional status of the tree; (4) size of the crop borne.
In general, old trees bear smaller nuts than do younger trees. Hence size of nut for a particular variety is only relative. The first few crops produced by a tree usually consist of nuts large in size for the variety; and then, as the tree attains age, nuts become smaller in size. Young trees make longer and thicker shoot growth than do older trees. There is, then, under normal conditions, a direct relationship between the growth made by a tree and the size that the nuts attain. The more vigorous trees not only produce larger nuts than those produced by less vigorous trees, but the hulls and shells of such nuts are thicker and constitute a higher total percentage of the total weight of the fruit.
The position of the nuts on a tree has an important effect on the size that they ultimately attain. In general, the nuts in the top are larger than those nearer the ground; and those on the strongest and most vigorous shoots of the top or lateral branches will attain a larger size under normal conditions than those located on weaker and shorter shoots or on the inside of the tree. Here again there is a direct relationship between growth of the tree and growth in size of nuts. All normal trees make longer and stronger shoot growth in the top than they do on the terminals of lateral branches, and the shortest and weaker shoots as well as the smallest nuts are generally on the lateral branches inside of the tree top.
Fertility of soil and moisture supply determine in large measure both the growth made by the tree and the size of nuts. The nuts borne on trees growing on fertile soils adequately supplied with moisture are generally much larger in size than those borne by trees on infertile soil or soil poorly supplied with soil moisture. Deficiency of either nitrogen, or moisture, or both is particularly effective in limiting the size of nuts produced. Pecans grown under soil conditions in which both nitrogen and moisture were deficient have been known to attain only about one-fourth the size of nuts of the same varieties grown in the same orchard but under conditions of clean cultivation and supplementary nitrogen applications. A prolonged drought during the time that the nuts are increasing in size very frequently causes them to be much smaller than they would have been had the moisture supply been adequate.
The size of the crop borne by a tree determines in a very large measure the size that the nuts attain at maturity. There is generally an inverse relationship also between the number of nuts borne in a cluster on a shoot and the size they attain. In this respect nut crops are little different from apples and peaches, which, too, are sold on the basis of size. In order to produce fruits of large size having a high market value, the crops are thinned in years of a heavy set of fruit. In the case of pecans, for example, thinning the crop at the time the nuts are growing in size on heavily producing trees is a very effective method of increasing the average size of the nuts allowed to remain on the trees. The earlier the thinning is done the more effective it is; however, it will increase the size of the nuts even when done as late as when the shells have started to become hard. No practical and economical method of thinning the crop of nuts has as yet been found; nevertheless it is well to bear in mind that a large crop borne by a tree generally means reduced average size of the nuts at harvest.