Northern Nut Growers Association Report of the Proceedings at the 43rd Annual Meeting / Rockport, Indiana, August 25, 26 and 27, 1952

by Unknown

TUESDAY MORNING SESSION

(Called to order at 8:30 o'clock, a.m., President L. H. MacDaniels presiding.)

Persian Walnuts in the Upper South

H. F. STOKE, Roanoke, Va.

My experience with the Persian walnut has been acquired in the Roanoke district of south-west Virginia. It is located 300 miles from the Atlantic seaboard and my trees are at an approximate elevation of eleven hundred feet. Roanoke is on the same parallel as Springfield, Missouri, and about thirty miles south of Rockport, Indiana.

This experience covers a period of more than twenty years with named varieties and seedlings of the species. I shall here attempt to present some findings that may be of some value to others similarly located.

For the sake of brevity I shall put the cart before the horse, the findings before the facts from which they are derived.

For the upper south and, in my opinion, for the middle west, late vegetating and blossoming is of prime importance for success with the Persian walnut. No matter how vigorous, prolific and precocious the tree may be, nor how fine the nuts, the variety is worthless for anything except shade if the crop is destroyed by normal spring frosts.

In the second place is winter hardiness. This is of two kinds; resistance to extreme cold, and resistance to the wooing of warm winter days that starts premature activity, followed by a destructive freeze.

My experience with the Payne variety is a case in point. Having read some place of the vigor, precocity and heavy bearing of the new variety, then called the Payne Seedling, I secured some scions of it from its originator and worked it on a young black walnut. The variety was already making a name for itself in Northern California and Oregon, not only because of its bearing habits but for the superb quality of its nuts.

During the first few years it did well despite its early starting in the spring, and bore heavy crops; then disaster fell. One spring the tree failed to leaf out at the usual time. On examination I found that it had winter-killed back to five-year wood. The winter had been unusually cold, and the tree could not take it. Pruned back, the belated new growth did not fully mature before winter so in turn was damaged, a phenomenon that recurred from year to year. Exit Payne as a Virginia prospect.

An example of the other type of winter injury was that of my first Crath Carpathian. I secured scions of this variety from Rev. P. C. Crath in 1929. The parent tree had been growing and bearing in the vicinity of Toronto and was apparently fully hardy. The scions grew vigorously on the young black walnut stock on which it was worked, and completed their longitudinal growth early in July, giving ample time for the ripening of the wood before winter.

After several years I noticed the bark on the south side of the trunks dead from so-called sun-scald. Activity had been induced by the warmth of the winter sun, followed by freezing. After some years the wood was killed back to limbs the thickness of one's wrist, and this has been again repeated. The tree was hardy in Ontario, but not in Virginia.

The nut of this variety, which to me is the Crath, is much superior to the average Carpathian, and I think might be well worth while in the north-east and along the Great Lakes, but not in the upper South nor the Mid-West.

Besides their winter weaknesses, both the Payne and Crath start too early in the spring for my conditions.

Broadview and Lancaster both blossom here in mid-season and, since both have a rather long period of producing pistillate blossoms, they seldom fail to produce a crop when properly pollenized.

Franquette and Mayette, both highly recommended as being late vegetating and producing excellent nuts, have offered me some difficulties of another order. With Franquette the chief trouble has been to get a suitable pollenizer. Like the Mayette, its pistillate blossoms appear ten days or more after the staminate blossoms and self-pollination is not effected. I tried King, recommended as a pollenizer, but it was too early to be reliably effective. When Franquette is properly pollenized it, with Payne, is one of the heaviest bearers.

Mayette in Virginia produces a fine, healthy, vigorous tree, but it refuses to produce pistillate blossoms. A dozen nuts is an average crop for a tree that should produce a bushel. It, like Franquette, demands a late pollenizer, but the pistillate blossoms are simply not there. Neither of these two late varieties have ever suffered winter injury with me, nor have been damaged by spring frosts.

I will not attempt to go into detail regarding all the varieties and seedlings that I have tried through the years; Eureka, that ranks with Mayette and Franquette for lateness, but refuses to bear, apparently for want of pollination; Chambers that was recommended along with King for pollenizing the late bloomers but not fully successful; Breslau, with its huge nuts but slow growth, in addition to an assortment of Carpathian seedlings. Of the latter my Caesar is one of the more promising with its vigorous growth, large thin-shelled nuts and ability to pollenize itself in some seasons. Gilbert Becker has reported it passing through Michigan winters unhurt.

As matters now stand, I believe Bedford, Caesar and Lancaster have proven the most satisfactory varieties to date under my conditions, although some seedlings I have grown appear even more promising. Chief of these are several that I grew from open-pollenized nuts of the Lancaster, which I am here exhibiting.

You will note that the one I designate as L-2 is an extremely large nut, considerably larger than its seed parent which it somewhat resembles. L-8 is of somewhat similar type, but smaller. L-3 and L-6, on the other hand, are of entirely different type. Much smaller, they are smooth, thin-shelled and well filled, with kernels running 50% by weight and of high quality. They resemble their seed parent, Lancaster, not at all but in type are much nearer Bedford, their probable pollen parent.

Another one of these seedlings, L-7, resembles Caesar, its probable pollen parent, far more than it does its seed parent.

Some years ago I hand-pollenized several blossoms of Broadview, using pollen from my original Crath.

One of the seedlings from these hand-pollenized nuts resembles Crath much more than Broadview, the seed parent. I have it here as C x B 2.

Aside from the apparent profound influence of the pollen parent on the offspring, there is the unexplained fact at that with the exception of L-8, all these seedlings are later vegetating than the seed parents and any of the suspect pollen parents. Of the Lancaster seedlings L-2, L-3 and L-6 are fully as late as Franquette and Mayette, blooming well after the first of May. Inasmuch as there were no Persians producing pollen anywhere near that time I can only believe that these nuts were pollenized by the black walnut on which they were top-worked. I intend to plant some of these nuts, and expect to produce hybrids.

This brings up the enticing subject of breeding Persian walnuts adapted to one's own conditions. I have no suggestions to offer scientists, but offer the following for the benefit of amateurs like myself.

If your grounds are cluttered up with varieties, as are mine, ingratiate yourself to some friend who has an isolated young black walnut tree by volunteering to convert it to the production of Persian walnuts. Select two varieties whose characteristics you desire to blend and that will pollenize each other, and grow seedlings from the resulting nuts. You can check results in as little as four years by taking buds from the seedlings at two years and placing then on black walnut.

Creative work, this. You will get the thrill of your life—if you are that kind of a person—and may produce something well worth while.

Persian walnuts are self-pollenizing if pistillate and staminate blossoms occur at the same time, but such usually is not the case. Crath, Breslau, Caesar and King produce their pistillate blossoms some days before their staminate blossoms shed their pollen, while Payne, Lancaster, Broadview, Franquette and Mayette produce their blossoms in reverse order. Of all those I have tested only Bedford can be depended to produce both types of bloom simultaneously and certainly and fully pollenize itself.

It is enlightening to keep a record of the blossoming time of each variety relative to others, but dates should all be recorded for the same year. Warm, early spring induces early blooming; late, cool weather delays blossoming. By my records, Payne pistillates were receptive May 3 in 1935, April 28 in 1937 and March 31, in 1945, a variation of over a month. All varieties vary with the season, but the variation is greatest with the early varieties.

There has been little disease among my Persian walnuts except that in wet seasons leaves and nut shucks are sometimes attacked by a fungous blight. In the city there has been no insect injury worthy of note. In the country, adjacent to wooded areas, insect injury is sometimes serious. Pests include spittle bugs, stink bugs and other insects that attack young leaves and tender growth. These check the leaders and cause late multiple growths that may fail to mature and hence winterkill.

In such locations the butternut curculio also attacks and destroys the young nuts. Avoid wooded areas if choosing a site for a Persian walnut orchard.

The most destructive pest with which I have had to contend has been the large black-bird or purple grackle. Oddly enough they are much worse in the city than in the country. As soon as the young are grown, about the middle of June, they appear in flocks and attack the nuts of the Persian walnut. At first, before the shell has hardened, they penetrate the nut apparently for the nectar which is the substance of the immature kernel. When the shell can no longer be penetrated they continue to eat away the husk, which is equally fatal to the nut. This continues until late in July, when the squirrels take over. Fortunately squirrels are highly allergic to a bullet from a 22 rifle.

In pointing out some of the hazards encountered in growing Persian walnuts in the East the writer has not intended to be discouraging but helpful. Persian walnuts of good quality can be grown in this section; full understanding of the factors involved make it possible, I believe, to grow them successfully on a commercial scale.

Varieties of Persian Walnuts in Eastern Iowa

Ira B. Kyhl, Sabula, Iowa

There are a great many varieties of Persian walnuts, many of which originated in the region of the Carpathian mountains and other parts of Europe and a few varieties in the United States and Canada.

I believe that some varieties now grown in the United States and Canada which originated in Europe may have come from the same tree as they appear to have the same shape, thickness of shell and flavor. I have as many as four varieties that are identical.

The Persian walnut has always been my favorite nut. I started with 2 or 3 varieties and now have 35 or 40 varieties and 200 trees most of which are doing well. Some are superior in hardiness and vigor.

In eastern Iowa at 42 degrees N. latitude minimum winter temperatures vary from 25 to 32 degrees below zero. Usually the minimum is 12 to 15 degrees below zero, but last winter it was 25 degrees below zero for several days. Only the hardier varieties will endure -25 degrees without injury, but -12 to -15 does not injure any variety very much.

Schafer is my favorite variety and it was not injured at -25 degrees. I have several of these trees, some from seeds, some top-worked on black walnut and the others grafted trees from a nursery. It grafts easily, grows rapidly and bears a fine nut.

A top-worked tree of Colby withstood -25 degrees without injury and is one of the most vigorous trees I have.

Fifteen seedlings from Crath Mayette and Crath Franquette seeds from the late G. H. Corsan, of Toronto, Canada, are developing into very fine trees, but are not yet bearing.

One of the first varieties planted, Broadview, grew rapidly and produced nuts after two mild winters, but the several trees of this variety killed to the ground after the -25 degrees of last winter.

Crath No. 1, Crath No. 39, and Breslau grew well until last winter when they were killed. Three Breslau seedlings did not winterkill.

Rumanian Giant, the first tree I grafted, killed back somewhat, but is recovering. This variety produces the largest nut I have seen and it fills well.

Top-worked trees of other varieties that were not injured last winter are Crath No. 5, Crath No. 12, SG No. 5, Crath No. 29, Graham and Crath Special.

Seedlings in the nursery row that stood severe temperature are
Carpathian D, NWF Nos. 1 and 3, FB O and FB OO, Fort Custer, Hansen,
Jacobs and others.

MR. STOKE: Does the black walnut bloom at the same time that the Persian walnut blooms?

DR. MCKAY: It bloomed near the end of the receptive period.

MR. STOKE: That first experiment of yours was trying to pollinize the black walnut with the Persian, but the reciprocal cross may be quite different, as Jones proved with the filberts.

DR. McKAY: That could be. We have no large amount of data on the reciprocal cross. These cases where it is said that the black walnut pollinates the Persian regularly and is producing good crops of nuts, I would consider doubtful until I see the seedlings, their growth and characteristics. Yesterday Mr. Bolten asked the question whether or not some walnuts that have large nuts could possibly be tetraploid or polyploid. A number of years ago I examined the chromosomes of one of these large fruited varieties, and it had the same chromosome number as the others, namely sixteen pairs or thirty two.

The whole question of chromosome number in nut varieties and species is as follows. So far as we know, all of the species have a constant number within the genus except the hickories where we have tetraploid species and diploid species. All of the species of Castanea, as far as we know, have the same chromosome number, and all of the varieties within each species have the same number. In the Oaks, which are related to chestnuts, we have an extremely large genus in which there is a great constancy of number. The pines, and all other cone-bearing trees make up another very large group in which chromosome numbers are constant. Exactly the opposite situation is found in the related family of alders and willows where the chromosome number is very variable.

PRESIDENT MacDANIELS: Unless there is some special question or comment on this subject, we will go on to the next item.

MR. LEMKE: There was a panel discussion about four years ago, and they were talking about what nuts to grow, and one of the men said, "Before you offer a man a good nut, give him a good nut cracker." That's been on my mind for some time.

Commercial Production and Processing of Black and Persian Walnuts

EDWIN W. LEMKE, Washington, Mich.

Sometime ago a group of nut minded men associated with Spencer B. Chase announced their findings on the quality of the wild black walnut growing in the area of Norris, Tenn. Nuts were gathered from 151 wild walnut trees. After judging, the group came to the conclusion that only one tree had a flavor that was considered by their standards as good. It is these good nuts that caused the formation of the N.N.G.A. When we speak of the good nut it gives the word commercial an entirely different meaning. It by necessity excludes most of wild black walnut kernels processed by the large cracking plants of Kentucky and Tennessee. The large crackers are willing to pay better prices for the improved black walnut but were they to rely on this source of supply they could not stay in business very long.

To produce and process, I chose the Thomas and Ohio variety and I have met with some success. The black walnut can be made to bear in the first and second year after grafting but this is but a novelty feature. Jones from whom I purchased my trees, told me that the black walnut could be classed with the Northern Spy Apple for coming into bearing. This has proven true. Commercial production of the improved black walnut is by its very nature small scale production. Because of this fact only small scale machines to process these nuts are feasible.

Since 1916 I have had time to reflect on the problem of the three basic machines needed. These are the huller, cracker and kernel picker. Fortunately for me I learned the machinist trade and had a machine shop at my disposal. I tried every way to hull the black walnut and finally accepted the commercial potato peeler as the best principle. I built several crackers and at last accepted the Wiley cracker as the best commercial cracker. The third machine is the picker which has yet to be assembled. This picker is copied after The Kenneth Dick machine with some variations in the separation process.

Let me briefly explain these three basic machines. As the nuts are gathered in the orchard they are brought to the huller in bushel crates. The huller is located in a separate room. This room has the floor depressed to catch the removed hulls that are flushed outdoors with the aid of running water. The cylinder of this huller is 30 inches in diameter and 14 inches high. It is made of 3/16ths boiler plate. Three inches from the bottom of the cylinder is a revolving disc smaller than the inside of the cylinder. The disc being small enough it allows a 5/8th opening around the inside of the cylinder. It is this opening that permits the hulls to drop to the floor. The nuts are held captive because there is no opening in the cylinder for them to leave until the discharge door is opened on the side of the cylinder. The cover of the cylinder has a 10 inch feed hole into which the nuts are fed. A 10 inch furnace pipe elbow runs from the hole to the serving trough into which the nuts are poured. A 10 inch pusher is used to shove the nuts into the huller and serves to keep the feed hole closed while the nuts tumble around. The disc runs at 250 RPM which is the proper speed to do a good job. While the nuts tumble around a stream of water is used to wash the hulls free from the nuts and force the removed hulls to the floor below. The disc is supported by a 1-3/8 inch diameter shaft that runs through the disc and is held central as it revolves in a flange containing a 3/4 ball bearing that fits into the end of the concave in the shaft. Up four feet from the disc is a link self aligning bearing that allows the shaft and disc to turn like a gyroscopic top. The shaft's pulley has 'V' belts connected to a 3/4 h.p. motor. I have hulled up to 40 bushels of clean nuts in 8 hours. The nuts after hulling are placed on drying trays indoors where temperatures are better controlled. The principal of this huller is that it separates the hull by centrifugal force. The hull drops down through the opening between cylinder and disc while the nuts riding on disc are discharged at right angles to the fall of hull. The machine is a separator.

The next basic machine is the cracker. This cracker is the Wylie cracker in principle and is made in Eugene, Oregon. Simply explained it could be likened to two pages in a book. One page is perpendicular while the other page is off the perpendicular about 7 degrees. The first page which is the anvil is fixed save for adjustments for nuts of varying size. The other page or hammer riding up and down through an inch and one quarter of travel is fixed to a crank below. Both of these pages or plates are heavy cast iron plates that are fluted and cause the nut to be cracked against these saw toothed flutes and while being cracked are revolved down through the plates. The plate moving at an angle forces the nut finally through a 3/8 inch opening where they fall into a rotary sieve. The sieve has three sizes of mesh. 5 mesh, 2 mesh and 3/4 mesh. The larger pieces go on through and are returned to the cracker. This cracker will crack up to 500 pounds per hour, and uses a 3/4 h.p. motor.

The last of the three basic machines is the picker. I have not yet built the picker but a number of the parts have already been machined and before long it will be a reality. The Kenneth Dick, picker, of Peebles, Ohio is the best for small orchards. It is essentially a separator using a conveyor belt which carries the cracked nuts to needles that pick up the kernels and deposit them on trays that at the timed moment accept the black walnut kernels. The discarded shells remain on conveyor and travel to the end and fall into a receptacle. After this process, further inspection becomes necessary but up to the present it is the best we have.

The black walnut is a messy nut to fool with but with the proper machines it soon becomes a pleasure to work with it. I can work all day hulling nuts and finish with clean unstained hands.

Processing the Persian walnut is a simple matter as compared with the black walnut. My Persian nuts are gathered and placed on drying trays. Most of the nuts fall free from hull and the stick tights are discarded as inferior. N.N.G.A. members need but write to the agricultural colleges in California, Oregon and Washington and a list of publications will be sent. One of the latest machines being offered is one that picks the nut from the orchard floor with a speed with which no human can compete. It has not only removed the back ache but the human back as well. The Persian walnut industry in the Pacific Coast states is big business.

There is only one organization that can and does disseminate the necessary knowledge and experience that will give the northern grown nut its proper place in the American diet. That is the Northern Nut Grower's Assn. You newer members have become heirs to knowledge based on the experiences of others which represents not only blood, sweat and tears but a lot of good hearty belly laughs. When one becomes nut conscious there is no turning back. It gives life a new approach and a finer meaning.

Black Walnut Processing at Henderson, Kentucky

R. C. MANGELSDORF, St. Louis, Mo.

MR. MANGELSDORF: Mr. Walker and Mr. McDonald are unable to be here today, and I don't know if I can fill their shoes or not, because I am not in the purchasing or processing end of the black walnut business.

We started this black walnut shelling operation a season ago at Henderson, Kentucky, with the idea of processing the nuts there and transporting the kernels to St. Louis for final processing and marketing. At Henderson, Kentucky we are located outside the city limit, and we have no fire protection, and as a result, the insurance rates on our building, storage sheds, and black walnuts in storage have been so high that we are looking around for possible plant location sites where we can reduce that expense of operation.

Another factor in our operation there is the transportation of raw material to our cracking site. If we have to transport black walnuts, which give an approximate 10 per cent yield, any distance, the freight adds materially to the cost per pound of the finished material. That is, if we have to pay 10 cents per hundred additional freight cost in transporting them from outlying districts to the cracking plant, that adds a cent a pound to the cost of the finished kernels. All such factors, have to be given weighty consideration, because our business is primarily concerned with making money for the stockholders. If we don't make money for the stockholders, they are not interested in seeing us continue the operation.

Mr. Walker and Mr. McDonald at the present time are out on a crop inspection trip and also making surveys of locations and availability of buildings or sites that might be more advantageous than the one at Henderson, Kentucky. It may be that we will continue the operation there, making modifications in the building, which will result in lower insurance rates. At the present time, with the new crop coming on, we are in a chaotic state of affairs, because we just don't know exactly what's the best path to follow in our operation at Henderson, Kentucky.

Are there any questions?

DR. MCKAY: Will you tell us something about how you handle the nuts in your plant, how they are hulled and cracked, and so forth?

MR. MANGELSDORF: It's a similar operation to what Mr. Lemke described. The nuts are brought in in burlap bags by the farmers and growers and are put in storage in cribs. The plant at Henderson, Kentucky, was a popcorn processing plant, with a large crib under roof where the nuts are stored. After the moisture content is reduced somewhat, they pass through a tumbling drum to remove any of the extraneous hulls and other dirt that might be adhering.

After the nuts are completely freed of all this extraneous matter, they are passed through a series of cracking rollers with screens. The nuts are cracked, by passing between two rollers like a wringer then passed over a shaker screen, the free nut meats passing through the screen. The large material that comes off of the screen is then passed between more closely spaced cracking rollers and then further sifted and screened. Then the various materials that have passed through the screens are run through a Smalley picker. This is nothing more than metal pins on a series of fingers rotating on a roller that presses against a sponge rubber roller. The nut meats adhere to the prongs or points. The shells, not being penetrated by the points of the pins, are not picked up. Then there is a comb that picks off the adhering kernels from the picker prongs. That's the principle of most of the shelling operations of the black walnuts. I don't believe any major changes have been made in the processing of black walnuts in the last ten years.

DR. COLBY: How do you remove the hulls?

MR. MANGELSDORF: We try to buy only hulled walnuts, the farmer and the grower removing the hulls in a tumbler and selling to us only the dehulled walnuts.

The kernels are packed in cartons and shipped to St. Louis for final picking of remaining shells and off-colored nut meats and graded for color, size and quality. After this grading separation is made, they are either packed in our 4-ounce vacuum-packed tins or 30-pound bulk cartons which are then sold through the trade.

MR. WALLICK: What percentage of kernels do you get?

MR. MANGELSDORF: I think our operation at Henderson, Kentucky this past season for all of the nuts that were grown and gathered in this locality was about 9.48 per cent yield of black walnut kernels by weight.

MR. WHITFORD: Do you get any improved varieties, such as Thomas, Stabler or Ohio?

MR. MANGELSDORF: No. With most of the nuts that we gather in our marketing operation very little attention is paid to variety or source. We don't try to differentiate and store them separately, but everything is processed as it is brought together.

MR. MCDANIEL: Do you have any indication that you get a better quality nut from one county or one area than you do from another?

MR. MANGELSDORF: That is a question that I can't answer, because I am in the research and development end of the business, and have very little to do with the purchasing and marketing of the nuts themselves.

MR. LEMKE: What do you do when you strike a day that is very humid and the nuts start getting moldy?

MR. MANGELSDORF: That is a bugaboo. I always say you don't have to be nuts to be in the nut business, but it sure helps a little bit. All the nuts that I have ever had any dealing with seem to be very susceptible to mold growth. If the moisture content of the nuts is above a critical level, mold growth takes place in the shell at a very fast rate. The only thing we can do in a case like that is to get the kernels in to St. Louis and destroy the mold growth or spores on the surface before it can grow so that the fungous mycelium is visible to the eye. The black walnut and pecan, if you examine them under the microscope, all seem to have mold growth on the surface of the kernels. I am inclined to believe that the nut kernel is not completely sterile in the shell and that through some manner or means the mold spores have been introduced onto the kernel, because immediately after shelling examination of these nuts under a microscope, will show some fungous mycelium on the surface of the kernels.

DR. MCKAY: One comment is that the pellicle of a black walnut or a pecan, is very hygroscopic. It tends to absorb moisture readily, whereas the kernel itself, being high in oil, does not take up water readily. That, apparently, is why there may be evidences of mold growth on the kernel though it may not be actually penetrating. It is only superficial, growing on the pellicle of the kernel, not on the kernel itself.

MR. MANGELSDORF: Right.

DR. MCKAY: Black walnut kernels are outstanding in their resistance to heat and will get rancid very slowly under conditions of high heat—not humidity. For example, we had some nuts in our attic for two summers in a place where it gets very hot, yet dry. Those nuts are in very good eating condition today. I don't know about pecans.

MR. MANGELSDORF: That's very true of black walnuts. Pecans have to be carried throughout the season in our cracking operations under refrigeration, but the black walnuts we can store out in any shed with tin roof. The temperature gets very hot, and it seems to have no effect whatever on the edibility or rancidity of the nut kernel.

MR. STOKE: You spoke of storing the whole nuts in large bins. There you may have an extreme amount of mold, too, if the nuts are damp.

MR. MANGELSDORF: We try to have storage conditions such that air has free passage through the bulk of nuts. The mold and the yeast are there and when they start to grow, their metabolism throws off quite a large amount of heat. As a result the molding process is speeded up like a chain reaction, and before long the nuts will be worthless for shelling.

MR. MANGELSDORF: We had nuts until just a few weeks ago from our last season's gatherings. That's almost a whole year.

MR. SALZER: Can you tell me if the farmer is paid by the weight of the nuts, or does he receive his pay after the kernels are shelled out? Does he receive more money if it contains a higher percent of kernels?

MR. MANGELSDORF: He receives his pay on the basis of the whole nut that he delivers to the plant, and we try to exercise some control over the quality of the delivery. Samples are taken and cracked, and if most of the nuts are rotten or the quality is very low, we may reject buying that entire lot, or we may discount the lot of nuts a certain amount, depending upon the percentage of the nut meats that are salvaged.

MR. MURPHY: Do you pay a premium for cultivated nuts?

MR. MANGELSDORF: That I can't answer, but I don't believe that they have this past season. I wouldn't want to go on record as to that. There is a tremendous difference in the flavor of what we call the "eastern" black walnut in comparison with the California or western black walnut. We think that the flavor of the California walnut is not at all comparable to the eastern black walnut.

MR. MCDANIEL: You don't notice any difference, do you, between the
Missouri and the Kentucky nuts?

MR. MANGELSDORF: No, not in my experience, but there is a tremendous difference in flavor between the eastern and western.

MR. ROHRBACHER: On what basis do you buy black walnuts?

MR. MANGELSDORF: I understand that each individual sale is an individual "horse-trading" deal, the price paid, depending upon the quality of nuts, moisture content, color and other factors. Of course, our aim is to buy the nuts as cheaply as possible and the object of the fellow selling the nuts is to get the greatest return that he can from what he has to offer. So we try to reach a happy medium in our dealings, and a lot of concessions might be made one way or the other with special lots that are offered for sale.

MR. WHITFORD: What sizes and grades of kernels do you have?

MR. MANGELSDORF: We have the large, medium, small and granules. Granules are very small pieces. Usually the prices paid for the nuts are not determined, actually, until the crop starts to move. Everybody has an idea what the market price will be for the nuts, but nothing is crystallized or brought to a focus until the first nuts are actually on the market. Then the nuts sold are examined as to quality, giving some idea of the future quality of deliveries that might be made in that section, and then prices can be established. As I say, it's a nutty business. I haven't grown very many gray hairs yet, but I expect to have many before I am through. And each new problem that arises in this nut business, when you reach a solution for it, invariably there are two other problems that are created, and if you are not wide awake, one of these problems can be much greater than the one that you just had a solution for.

MR. DAVIDSON: Do you know anything as to the bearing of black walnuts this year as compared to previous years?

MR. MANGELSDORF: Mr. Walker and Mr. McDonald are out at the present time making a crop inspection tour of the various localities, and I have had no report as to what the condition of the crop will be this year.

MR. WHITFORD: Which grades bring the highest prices?

MR. MANGELSDORF: The large particles of kernel demand a premium over the smaller sizes. That is one of the discrepancies in the shelling operation, that the material that costs us the least money to produce gives the largest returns. When you have small pieces, the operation of removing the last remaining shells and off-colored particles is much greater than with the large kernels. One large kernel amounts to considerable weight and you may have to pick up many small particles to represent the same weight.

PRESIDENT MacDANIELS: We appreciate very much your talk, Mr.
Mangelsdorf.

One thing that interested me was your statement that having large pieces was an advantage. That question has been argued on the floor of these conventions a number of times and there have been those who claimed that the larger pieces were all ground up anyway and that the varieties from which you can recover large pieces were of no particular merit commercially.

The next paper is, "Nut Shells—Asset or Liability?", T. S. Clark of the
United States Department of Agriculture, Regional Laboratory, Peoria,
Illinois.

Nut Shells—Assets or Liabilities

T. S. CLARK, Northern Regional Research Laboratory,[1] Peoria,
Illinois

ABSTRACT. The value of nut shells as materials for agricultural and industrial use is discussed. Problems of plant location, shell collection, processing, and hazards are considered. Applications and specifications are illustrated.

We are particularly pleased that the Northern Nut Growers Association is presenting this opportunity for a discussion of nut shell utilization. The Northern Regional Research Laboratory feels that it has played an important role in what is now becoming a new industry of increasing magnitude. For the benefit of those who are not already acquainted with the Laboratory, permit me to digress momentarily to explain briefly its organization and functions.

The Northern Regional Laboratory at Peoria, Illinois, is one of four large research laboratories established by an act of Congress in 1938 and placed under the administration of the Bureau of Agricultural and Industrial Chemistry. The function of these laboratories is to conduct research and to develop new chemical and technical uses as well as new and expanded markets for the farm commodities and byproducts of the regions in which the laboratories are located. The commodities studied at the Northern Regional Research Laboratory are the oilseeds, cereal grains and agricultural residues which include corncobs, stalks, straws, sugar cane bagasse, hulls and shells of nuts and fruit pits. Because of the great similarity in chemical and physical characteristics of the residues all research on these materials is conducted at the Northern Laboratory.

During the time that the Northern Laboratory has been actively investigating shell materials and other agricultural residues we have been in direct communication with operators of shell grinding plants; some of these have been visited. We have received numerous letters and calls for information and assistance in solving grinding problems, or in using the ground products. Through these contacts and our experiences we have learned much about the factors that lead to success or failure in this utilization. Ten plants are now producing a variety of ground shell products useful in both agriculture and industry.

When the Northern Laboratory was organized, only one plant, established originally by the California Walnut Growers Association, was grinding nut shells. This plant, following a number of operational difficulties and administrative changes, now processes 40 tons or more of shells per day and produces a wide variety of ground products including exceedingly fine flours for use in plastics and plywood adhesives. It has been said that this plant processes all of the English walnut and apricot pit shells and 80 percent of the peach pit shells available in California.

The Laboratory has attempted to determine the amount of shells and pits available commercially in different areas. Data of this nature has been obtained for the larger cracking plants but there are many small operations for which we lack this information. "Agricultural Statistics" compiled and published annually by the U. S. Department of Agriculture provide an excellent source of information regarding production and, in many cases, the disposition of farm commodities. For example, the production of pecans in 1951, presented by states, totaled more than 73,000 tons for the 10 states reported. However, no data were available regarding marketings in-shell, or the quantities remaining on the farms or in the orchards. Thus, the quantity of pecan shells actually available for processing can be determined only through surveys of cracking plants. Only limited information is available concerning black walnut shells and this has been obtained through the cooperation of shellers or crackers.

In some areas fruit pits, such as apricot and peach pits, accumulate at canneries or freezing plants. Similarity in character of the pit shells to those of the nuts permits their use in plants grinding nut shells. Thus, the supply of raw material in any area may be augmented by inclusion of fruit pit shells.

Collection of nut shells for grinding operations is a relatively simple procedure, particularly where grinding is done at a cracking plant. Where shells must be collected over large areas both rail and truck transportation are used. If fruit pits are considered, provisions should be made for removal of residual flesh or pulp before the pits leave the canneries. In the cases where the pits have been cut during processing of the fruits, the released kernels should be removed before shipping the shells. Pit kernels are valuable for their oil content.

Shell Use During World War II

The production and maintenance schedules set up during World War II resulted in the development and expansion of uses for ground shell materials. Fine flours from walnut shells were needed as extenders in plywood adhesives. Soft grits from various shells were used by the Army Air Forces in the air-blast method for cleaning airplane engines and parts. Grits were required for deburring metal stampings and flash-removal from molded plastics. These uses have expanded considerably to meet civilian needs since the war.

Grinding Nut Shells and Fruit Pits

As uses for ground shell products were developed the Laboratory sought advice of grinding equipment manufacturers for information on the design and construction of suitable grinding plants. Only limited tests had been made and data were not readily available in any published form. Consequently the Laboratory undertook an extensive study on grinding nut shells and fruit pits as part of its research on agricultural residues.

These studies were not limited to grinding only, but included methods of separation and classification based on physical characteristics of the raw materials; the relation of associated mechanical operations; a consideration of the hazards; the problems of labor, management, and merchandising.

A number of fires have occurred in plants grinding nut shells, corncobs, stock feeds, and similar materials. In most cases the causes of fire have been other than the grinding operation. From a consideration of the causes of fires a number of safety precautions have been developed. Good plant housekeeping is paramount. This is essential, not only because of influence of dust and dirt on the maintenance of motors and equipment, but because of the highly explosive nature of shell dusts. The U. S. Bureau of Mines has cooperated closely with the Northern Laboratory in evaluating the explosive hazards of the shell dusts.

Many of the present operators of shelling-grinding plants have benefited from the information and assistance available from this Laboratory. The cooperation of equipment manufacturers has aided considerably in extending the scope of the Laboratory's studies.

The Northern Laboratory has published bulletin AIC-336, "Dry Grinding Agricultural Residues, A New Industrial Enterprise" that summarizes the research conducted to date. This is the first time that such data on engineering and design has been assembled and published to cover this field. Copies of the bulletin may be obtained by addressing requests to the Northern Regional Research Laboratory, Peoria, Illinois.

Plants designed to produce at least 1-1/2 tons per hour of ground shell products will cost upwards of $60,000. A well-engineered plant of such size will require three to five men per shift. Among other factors, the working capacity of a grinding plant depends upon the quantity of shells available and the ability of the organization to merchandize its products. The plant should be located in an area in which at least 5,000 tons of nut shells or fruit pits are annually available at low transportation costs.

Uses of Shell Products

The more important uses for nut shell products, together with their specifications for particle size, are shown in Table 1.

Table 1.—Uses for ground nut shells and fruit pits

+————————————————————————+——————————+ | Applications | Size | | | | | Deburring, cleaning, burnishing and polishing | | | in metal stamping, electroplating and | No. 10 to No. 50 | | plastics industries | | | Soft-grit blasting | No. 10 to No. 30 | | Fillers for plastics and plywood adhesives | Finer than No. 100 | | Insecticide diluents and carriers | Finer than No. 140 | | Explosives | No. 10 to No. 100 | | Fur cleaning | No. 10 to No. 100 | | Poultry litter and mulch (almond and peanut) | 1/4 to 3/4 inch | | Fillers for fertilizers (almond and peanut) | Finer than No. 20 | +————————————————————————+——————————+

Experience shows that no matter how nut shells or fruit pit shells are ground both under- and oversize particles will be produced. The hard, friable character of most of the nut shells makes their reduction to fine size particles less difficult than for tough materials, such as corncobs, or fibrous materials such as woods. Shells from almonds because of their bulk and very fibrous nature are somewhat less convenient to handle than other shells. Good business practice shows that sales outlets should be found for each fraction so that grinding expenses can be kept at a minimum.

Because there are some differences in physical characteristics of nut shells and fruit pits all shell products do not necessarily meet the same specifications, nor have the same uses.

Industrial Cleaning and Finishing

Oil, dirt, corrosion products, stain, paint, grease and the like can be removed from metal surfaces by air-blasting with soft grits prepared from shells of walnuts, pecans, peach pits, and similar residues. This method was developed originally for the Navy to use grits from corn-cobs for cleaning aircraft engines and parts. The method is inexpensive and foolproof because surfaces are cleaned without change of dimensions. No pitting or abrasion, such as produced by sand blasting, occurs. The method is particularly useful with mild steel, nonferrous metals, alloys, and parts that must be maintained at close tolerances. Modifications of the blast method are used in finishing molded plastics, metal die-castings, and machined parts. One manufacturer of precision instruments states that his company saves $100,000 a year in finishing parts with shell grits.

Many stamped metal articles and molded plastics are deburred, cleaned, burnished, and polished by tumbling in drums containing shell grits. Various grades of grits are required depending upon the nature of the pieces being finished.

Fillers for Plastics and Plywood Glues

The Laboratory has studied the use of shell flours for use in plastics and plywood glues. Many of these flours are now in regular commercial use. Flours for these applications are prepared in various grades, all finer than 100-mesh. Use of these flours not only improves the properties of the final products but also reduces the cost of the products. Molded plastics prepared with fine flour from English walnut shells have exceptionally fine surface finish.

Insecticide Carriers

The insecticide field provides a good outlet for shell flours. Flour from walnut shells was the first of this type of material to be used for this purpose. Often the active ingredient in a finished insecticide is present in quantities of less than 1 percent. Custom grinders should plan to recover the flour as a co-product of their operations rather than attempting to grind to flour alone.

Explosives

Large amounts of shell grits and meal are used as diluents in the manufacture of dynamite. Material for this use ranges in size from No. 10 to No. 100, the requirements of the individual manufacturers falling within much narrower limits as to size.

Fur Cleaning

Furriers have found that various ground shell products are very effective agents for cleaning furs. Size requirements for this purpose are broad, the limits being dependent upon the cleaning equipment maintained by the furrier. The natural oils present in some shell products are considered advantageous for this application.

Sundry Applications

Stock bedding, poultry litters, fillers in feeds and fertilizers, mulches, charcoal, tannin and abrasives in hand soaps are some of the other products that are prepared from nut shells. The shell products cannot be used interchangeably but must be selected in accordance with their chemical and physical properties.

I hope that the foregoing brief discussion has conveyed to you the potential value that lies in the piles of shells accumulating at the cracking plants, and that these accumulations can be converted from expensive wastes to profitable products.

FOOTNOTES:

[Footnote 1: One of the laboratories of the Bureau of Agricultural and
Industrial Chemistry, Agricultural Research Administration, United
States Department of Agriculture.]

The Propagation of the Hickories

(Panel Discussion led by F. L. O'Rourke, East Lansing, Mich.)

MR. O'ROURKE: I hope that we can have a rather stimulating session on hickory propagation this morning. Last year we had a session which was supposed to take in propagation of all nut tree species. However, we never got away from Chinese chestnuts. It was Chinese chestnuts from the start to the finish. The Program Committee this time thought that we should limit it to one group, and they chose the hickories.

I have compiled a review of all the literature pertaining to the hickories and passed it out yesterday afternoon. I hope that some of you have had a chance to read it and will have some questions to ask us this morning.

In order to really have some help, I am going to call upon Mr. Louis
Gerardi of Illinois, Mr. Ferguson of Iowa, Mr. Max Hardy of Georgia, Mr.
Ward of Indiana, and Mr. Wilkinson also of Indiana and Mr. Bernath of
Poughkeepsie, New York.

The subject matter of the panel will be limited to the propagation of hickories, which includes the pecan.

Who has some questions that they'd like to bring up?

MR. SALZER: Which varieties will grow on fairly wet soil?

MR. O'ROURKE: That is a question pertaining to culture, rather than propagation, but we can still allow it. Which varieties—I presume you mean species, is that correct?—will grow on fairly wet soil? I think Mr. Ward has a little bit of black soil in that good, old state of Indiana.

MR. SALZER: I mean soil that doesn't dry well in the spring. I have one spot that's too wet for chestnuts.

MR. WARD: I wouldn't put any hickory nuts on it. You are going to find it is going to be very difficult for if the soil is the least bit heavy or wet, the hickory nut does not do well at all. In the Wabash bottoms there is a lot of this black soil that is overflowed every year, and some of the finest hickory nuts and some of the finest pecans that you can find in the country are there. Sometimes I have seen water marks on those hickory trees several feet from the ground in the spring of the year and sometimes in the summer, yet they come through with a good crop of nuts. Underneath it is a strata of gravel so that the soil drains out in a hurry.

MR. SALZER: This has subsoil drainage.

MR. WARD: The soil around Rochester is very heavy like what we call slashland type of soil here in Indiana, and where this occurs we find that the hickory nut does very, very poorly. I wouldn't advise putting them on such soils. The black walnut will grow a lot better in places like that.

MR. GERARDI: In Illinois we have that deep, black soil and we just call it plain gumbo. It's all filled-in soil, and I never have reached the bottom. It's at least 20 feet thick. And these swamp hickories—I think Reed was the one that called them swamp hickories—thrive there. They can be two months under water six foot deep, and still bear wonderful crops. You can get a wagon load of them in that mucky soil.

MR. CALDWELL: The hickory in New York State which will stand the most moist conditions is the bitternut hickory, and with that root stock you may be able to get some of the others through. The shagbark will withstand considerable moisture if it has deep soil. The bitternut does well on shallow soil or the soil that is made shallow by high water.

MR. O'ROURKE: The bitternut, then, will survive wet conditions. This is of interest as far as root stocks are concerned. I am wondering if anyone would like to report on the ability of the pecan to take wet soil conditions.

MR. WILKINSON: They will turn out all right if they have dry feet during the summer months, but they will not stand wet feet all summer.

MR. O'ROURKE: Will the bitternut do better, or would the mockernut?

MR. WILKINSON: I am not well enough versed on that to say. But the pecan, I have seen them stand under water for weeks at a time two or three times during the winter, water 20 feet deep and not affect them at all. But if they are around in a place where the water stands in July and August, they won't take it.

MR. O'ROURKE: Any other discussion on stocks that will take wet soil conditions? If not, let us take up Mr. Beckert's question: When do you take scion wood of the shagbark hickory? Who would like to answer that? Mr. Gerardi?

MR. GERARDI: The time I like best, the time it can be done in our particular area is the latter part of February. Leave it on the tree as long as you can before any sap rises.

MR. O'ROURKE: You would say probably 10 days to 2 weeks before the bud scales would break?

MR. GERARDI: That's right, before any growth begins.

MR. O'ROURKE: Any other comment on that? Dr. McKay?

DR. MCKAY: I want to ask the question about which there is difference of opinion. Do pecan seed have a rest period, and is there any difference between pecans and hickory in that respect?

MR. HARDY: I am not sure that I can answer the question exactly. Most pecans planted for seed have been allowed to dry before they are harvested, and it is general practice to stratify them either in sand for planting in the spring or planting them immediately in the fall. I am inclined to think that there is very little rest period in pecans and that if they were planted immediately from the tree that perhaps they would begin to grow almost immediately.

DR. MCKAY: I think that's true. The seed will germinate quickly. But can you plant dry seed any time during the winter?

MR. HARDY: Once they are dried I think they must go through after-ripening conditions.

MR. O'ROURKE: Do I understand you correctly that you do feel that the pecan must be after-ripened?

MR. HARDY: Yes, if permitted to dry.

MR. O'ROURKE: The work of Burdette in Texas a great many years ago has indicated that the pecan seed does not have a rest period. Mr. Wilkinson, what has been your experience in germinating pecan seeds?

MR. WILKINSON: I usually like to either plant or stratify soon after gathering, although one time I had some off the shelf of a grocery store in March and got excellent results. One thing more about time of cutting graft wood. I never like to cut it for at least 48 hours after a freezing temperature, regardless of time. I would rather cut it in April with the buds green than to cut it in the first of March right after a freeze. I have had excellent results just this spring cutting extra graft wood with green buds on. But if you cut it within 48 hours after a freezing temperature, you might just as well throw it away.

MR. O'ROURKE: I am very glad you brought that out. Irrespective of whether it be pecan or hickory, I believe it would work the same, that the scion wood should be cut when it is moist, and that is not the condition after a freeze, when it is in very dry condition.

Let's get back to this seed propagation now. I am asking anyone here, can you throw any light at all on the need for stratification of pecan or hickory seed of any species.

MR. CALDWELL: I have read in several publications that hickories should be stratified over the winter period before planting for spring germination. I always find things a little bit different, so a year ago at the greenhouse I took seven different sources of seed of shagbark hickory, Carya ovata and one source of Carya ovalis. Some of those seeds germinated within three weeks from the time I put them in, and after a month and a half I had a full stand in all cases. I don't think that more than 2 per cent of the seeds failed to germinate. They were planted in warm greenhouse, with a minimum of, about 68 degrees at night and about 90 during the day. They were planted in a combination of peat and garden soil; no special care other than water. I have had no trouble since the seedlings have continued to grow, even though the seeds were planted only two and a half inches deep. So it may be that there is no need for stratifying hickories.

MR. O'ROURKE: Your experience is the exact duplication of Dr. Lelia Barton's of the Boyce-Thompson Institute. She found that hickory seeds germinated from three weeks, as you did, to a number of months, when put in a warm greenhouse. Apparently the difference in time is related to the thickness of the seed coat or possibly to an inhibitor in the pellicle rather than to any need for after-ripening. I think that Burdette in Texas also pointed out that thick-shelled pecans took longer to germinate than thin-shelled pecans.

MR. PATAKY: If you take a nut of any kind and let it dry and plant it, you will get quicker germination than if you plant it soon after harvest. I don't see any difference in taking a nut and planting it and stratifying it. If planted the rodents will get it, but if you put it in something all winter, it will be there in the spring. I don't see any reason for planting a nut in the fall, taking a chance of rodents getting at them. If you plant them in the spring, they come up so much quicker that the rodents don't have a chance to get at them. They got nearly all of mine that I planted in the fall.

MR. HARDY: A good many nuts don't have any rest period requirements. I think it probably is a matter of convenience as to the manner in which they are handled. I have talked with nurserymen in the South. If they get the nuts in the fall they may either plant them in the fall or stratify them over winter and then plant them in the rows in the spring. If they get them in the spring, they soak them for a day or two days in water before planting. Perhaps the dry nut is slow in taking up moisture direct from the soil, and they are primarily interested in getting a uniform stand of trees so that they handle it in such a manner that all the nuts will grow at the same time. And I believe many will agree that a dry nut planted in the spring will show considerable variation as to the time in which they appear above ground.

MR. O'ROURKE: The suggestion of soaking them in water a few days is well taken, because a great many have recommended it. Most folks recommend changing the water daily. By changing the water you replace the oxygen which would be in the water, and you also eliminate any toxic substances which may have leached out of the shells during the preceding 24 hours.

DR. MCKAY: I'd like to mention the reason for raising this question. Dr. Crane has the idea that there is no definite rest period in the pecan nut; if they are soaked in water they will sprout at any time.

I decided I would test that hypothesis, so I stratified one group of nuts of about four pounds. Another lot of four pounds I kept in the laboratory dry all winter long. Then I planted the two lots of nuts this spring together, side by side, in the cold frame. Today there is not a single seedling growing out of the dry lot, and there is a perfect stand in the group that was stratified.

To me that means that there is a definite rest period in the pecan seed.
I don't see how you can get away from it.

MR. O'ROURKE: I am going to stick my neck out a little bit. I have absolutely no basis to make this statement, but it does give us something to think about. That is the greater the distance towards the north that certain species of plants may have migrated or disseminated, the greater the rest period requirement. That is a protective device for a species to persist in northern climates, because if it were not for this rest period, those seed would germinate in the fall of the year, and the young seedlings would be frozen out immediately. But by having the rest period requirement over winter, the seedlings do not germinate until the following spring, and the plant can persist. I am speaking now in general of northern plants. I am wondering if the pecan species in itself may not be variable in that the southern pecan does not need a rest period, and the northern pecan is beginning to develop the rest period requirement.

MR. HARDY: Mr. Chairman, I am inclined to think there may be some other factor entering into the picture there. A pecan carried through winter in a dry condition at normal room temperatures would be liable to develop quite a bit of rancidity by spring. Furthermore, nuts that have been held over so long in a dry condition may still be good and may germinate the second year. I'd hesitate to destroy that planting until next spring, and to my notion that does not indicate dormancy so much as it would possibly indicate the inhibition of growth by some other products developed during that storage period.

MR. O'ROURKE: You have brought up a very important point and something we should not neglect. It may be that drying to a certain degree will induce dormancy, a grievously overworked word, but you know what I mean. It may take two years for the seed to germinate, as Mr. Hardy has suggested. If you can leave them in that cold frame over this winter, maybe you can tell us next year just what happened.

MR. PATAKY: If we take nature's way, watch a squirrel plant a hickory or black walnut. He will bury it about an inch deep, and it will stay moist all winter long, the same as if it were stratified. But if you take a nut and store in a hot place you are going to slow up or kill that germ.

You can do that very easily in a chestnut. Take a little advice from nature itself in the locality where you are. If you are in the South, that nut can start growing in the fall, and it probably won't hurt it, but if you are in the North, you don't want to start a nut growing in the winter, because it's going to get winter killed.

MR. O'ROURKE: In all probability the amount of oxygen about the germinating seedling might be quite a factor. The shallow planted seed will have more oxygen available than deep planted seed, everything else being equal.

If we are finished with the discussion or germination of seeds, we can go on to the next question, that of a suitable root stock for hickory—and that could keep us here for two or three days. Have you had some experience, Mr. Ferguson?

MR. FERGUSON: We use the pecan and the shagbark as root stock for the hickory group. Formerly we have used some of the bitternut, but we do not use it any more. Some of the hickories will grow well on pecan, and some are not satisfactory at all. What they will do in old age is hard to tell. We have a few in the orchard down in Mr. Snyder's farm. I think we have Stratford on pecan, which is not satisfactory. Pecan grows too fast for the Stratford, and some way or other it just doesn't work.

MR. O'ROURKE: Are you familiar with Mr. Lassiter's stock work?

MR. FERGUSON: He has used the Rockville as an intermediate stock on pecan. The Rockville is a hybrid of the pecan and the shellbark.

MR. O'ROURKE: Mr. Lassiter sent us a letter in which he stated that he had a good variety of shagbark that when grafted on the Rockville intermediate stock produced much better nuts than on pecans alone. Is that due to the exceptional vigor of Rockville which apparently is a hybrid and may have hybrid vigor? Again, we can only guess. This interstock problem is a big problem. We now have some evidence that pecan is not always satisfactory for all varieties of hickory, although Mr. Dunstan at Greensboro, North Carolina, states it's been satisfactory for every variety he has worked upon it.

MR. HARDY: I am inclined to believe that root stocks and scion varieties worked in the north and grown in the north or worked in the south and grown in the south may not react the same.

MR. WILSON: I think you are right on that.

MR. O'ROURKE: Mr. Gilbert Smith's report of yesterday indicated a pecan was not satisfactory with him in New York State, and that may bear out the comment that Mr. Hardy has made.

MR. GERARDI: Well, I think that is true enough, myself. In southern Illinois I find that the bitternut hickory root for shellbark or shagbark don't seem to be satisfactory at all. With the shagbark on pecan, the variety of shagbark makes a difference. Some varieties of shagbark, and shellbark hickories seem to do all right, and then again others don't. It's going to need further study to determine what varieties will stand on pecans, what will stand on bitter hickories, or what will stand on regular ovata stock. I think that the nurseryman's wisest way is to use stocks of the same species as the scion and then he is on the safe side. Because the bitter hickory grows faster, the nurseryman may find it advantageous to grow the bitter hickory stock in preference to the other two.

MR. O'ROURKE: The bitter stock makes a hickory big enough to graft in two or three years.

MR. GERARDI: In two or three, and four or five for the shagbark. Shagbark or shellbark varieties on bitternut may grow for three or four years and then die.

The pecan does well on the bitter hickory and the bitter hickory on the pecan, but I have no reason to grow any bitter hickory because I don't like the nut. I think it's a waste of time to fool with it that way.

As far as the hybrid pecans are concerned, the pecan root is certainly the right stock to use on all hybrids. They grow very satisfactorily and bear well.

MR. WHITFORD: I have Gerardi and McAllister hybrids growing on pecan, and the Downing overgrows the pecan.

MR. O'ROURKE: To summarize some of this information that we have gathered this morning on root stocks, it seems that different clones behave differently on the same stock. That is true, we know, with other plants, such as apple. Instead of saying that shagbark is not compatible with pecan, perhaps we should say that the Davis or the Wilcox variety of shagbark is not compatible with a certain type of pecan. It's going to take years of effort to find out the truth of the matter.

MR. WARD: Sometimes you will find that a two-year-old scion, if you can get a dormant bud coming, is better than the matured wood from last year. I'd just like to get an opinion from some of the growers what they use for topworking stocks for grafting.

MR. FERGUSON: I think one thing quite important is to get scion wood that has a good layer of wood around the pith, whether one-year wood or two-year wood. At the base of the year's growth it will have a lot more wood in it. At the tip the wood around the pith is thin.

MR. O'ROURKE: Some years ago Dr. MacDaniels stated that a good scion may be made with the tip of the scion in the one-year wood and the base of the scion in the two-year wood.

Mr. Bernath at Poughkeepsie, New York, has done some bench grafting of hickory. Why other people have not done so, I do not know, and I'd like Mr. Bernath to tell us briefly just why he likes to bench graft hickory.

MR. BERNATH: I like it because I do my work in the wintertime under glass. I have no time in the spring to fuss with outside grafting. So if you gentlemen would like to hear it, I will tell you all about it.

Many years ago when I learned my profession, we had difficulty in finding a method to graft oaks. We finally did find a method that would take and which I have found successful with hickories.

The stocks are dug in the fall and stored heeled in earth. When I am ready to graft I put them on a table, along with the scion wood and start grafting. I use the side graft at the crown leaving a short spur above the graft. Leave them unwaxed and layer them in moss peat in a glass covered frame in the greenhouse with some ventilation. In three or four weeks' time, when the union has formed and just before the leaves come out, take them out and plant them in a cold frame outside. Of course you have to put glass on it to protect them from frost, as well as intense sun. Here you can use part peat and part soil. Leave them there for one year in those frames, with partial shade, until they get fairly high so they shade each other. They can then be set in the nursery row.

MR. O'ROURKE: Mr. Bernath, I know there are some folks here who are nurserymen and who are interested in the cost of production of a finished tree. Do you feel that you can produce a tree to transplant any height you want to select, five, six feet, so on, as cheaply according to this method of bench grafting in the greenhouse as if you bud it or graft it in a nursery row?

MR. BERNATH: That's a question. I have never kept a record of that. It is all right for a young man who is able to get down on his hands and knees and graft, but for me that wouldn't do.

MR. FERGUSON: What temperature do you use in the frames?

MR. BERNATH: About 65. Sun heat naturally will raise it. Care must be used to ventilate the frames in the greenhouse to prevent condensation soaking the grafts.

MR. FERGUSON: Do you carry higher temperatures for walnuts?

MR. BERNATH: All of them about the same. You follow the method just the same as nature. If you follow nature, you will never go wrong. But you have to watch out for fungus in the case, because if you have excessive temperature, the fungus disease will get in your case and ruin the whole thing.

MR. WARD: I presume, Mr. Bernath, when you set out a tree and get a hundred per cent stand it's going to reduce your cost.

MR. BERNATH: Yes, because you have a better take, because you have everything under control, moisture, heat, ventilation, and so on.

MR. BECKERT: Are the hickory stocks potted before you graft, or are you grafting bare roots?

MR. BERNATH: Hickory and oaks are bare rooted. They are too long to pot.

MR. SHESSLER: How many years are lost in this method of bench grafting compared with field grafting trees in the nursery row?

MR. BERNATH: Quite a few. The gentleman is right, if you graft outside where the tree remains, you get a big growth on it.

MR. SHESSLER: In other words, a tree grafted out in the field will have nuts on it three years sooner?

MR. BERNATH: Yes if you leave it where it is. But if you transplant it, look out for a large tree. It is likely to fail.

Bench grafted trees transplant easily. The roots are limited and little of the root system is destroyed.

MR. WILKINSON: I have been propagating for about 39 years, and I have grafted thousands of pecan trees in my nursery, and I have only a few trees growing from grafts. Budding is much more successful with me. Several times I have had up to a 90 per cent stand by budding.

MR. GERARDI: I have tried bench grafting but it sets you back three years in the nursery to get a tree of equal size compared to grafting in the nursery row. If you want a small tree, it's all right. And then again, it's your help situation. If you have got to set them out, they handle the grafts like brush, and I don't like that. Hickory is not hard to graft in the field. I think if you set 10 you get 9 to grow. For scions I go back on two-year wood and oftentimes on three-year wood where there are buds. I don't have trouble at all. With pecans, you have a little more difficulty, because the wood is more pithy inside and doesn't grow so well.

MR. BERNATH: With any tree, I don't care what it is, give me one-year growth, this year's growth, and I am going to have wonderful success. When you take the old wood you have to be sure that you have buds.

PRESIDENT MacDANIELS: This last discussion certainly shows that, there is more than one way to get results. The fact remains that all these different men are producing hickory and other trees by various different means of grafting and budding. They have their own techniques which worked. What there is behind it from a scientific basis we probably don't understand too well at the present time.

I now call on Dr. McKay to present his paper. Dr. McKay.

A Promising New Pecan for the Northern Zone

J. W. MCKAY and H. L. CRANE[2]

In late 1949 Professor A. F. Vierheller, Extension Horticulturist at the University of Maryland, College Park, obtained two small pecans from an exhibit at the Prince Georges County Fair, Upper Marlboro, Maryland, which he sent to the Office of Nut Investigations at Beltsville, Maryland. These nuts were very thin shelled and contained solid, well developed kernels very light in color and attractive. We gave them no particular heed until the fall of 1951, when the authors together with Professor Vierheller, P. E. Clark, County Agent of Prince Georges County, visited the tree on which they had been produced. We found also a number of other pecan trees nearby. All of them were on an old southern Maryland estate known as Brookfield. The present owner is John C. Duvall, whose address is Naylor, a small southern Maryland community located about 25 miles southeast of Washington, D. C. in the heart of the tobacco growing area.

Origin of the Duvall trees: The present trees probably grew from nuts sent to Maryland from the vicinity of Iron Mountain, Missouri, by a friend of the Duvall family named Mrs. Mary Medora Johnson. Mrs. Johnson had lived in Maryland as a neighbor of the Duvall family and when she moved to Missouri she apparently was so impressed with the native pecan that she sent nuts to her friends in Maryland for planting. This must have happened about 1850 since the oldest trees at Brookfield are estimated to be about 100 years old and Mrs. Johnson was a friend of John C. Duvall's grandmother. In terms of the human life span the trees are thus three generations removed from the time of planting, a time period which fits fairly well the estimated age of 100 years based upon size of the trees.

Description: The three largest trees are approximately equal in size and undoubtedly represent the original planting. The eight other trees are all smaller and could well have originated as seedlings of the original three. Five of the largest trees have been given numbers 1 to 5 and will be referred to by number. Duvall No. 1, 2 and 5 are the three large trees situated more or less in a circle surrounding the old mansion, each about 100 yards from the others. The smaller trees are located more or less between and around the larger ones, the old mansion being on a slight knoll in the center of the planting. The original dwelling of Brookfield is now crumbling ruins, part of the building being more than 200 years old, according to Mr. Duvall, who lives in a modern new country home across the road from the original mansion. The three large trees have a diameter at breast height of approximately 4 feet and all of them have a branch spread of more than 150 feet. They are 75 to 100 feet tall. All of the trees have very narrow and pointed leaflets characteristic of Texas and southwestern varieties, and they are remarkably free of insect pests and diseases.

The nuts from this group of seedlings are variable in size and appearance as might be expected of those from any group of pecan seedlings. However, one of the most striking characteristics of all the nuts is that the kernels are solid and well developed. This is an unusual characteristic for pecans grown in the latitude of Washington, D. C. In all of the varieties that are usually grown in this area none which regularly fill their nuts well are known. Another outstanding characteristic of all of the nuts produced by these seedlings is the bright, attractive color of the kernel. In fact, when the nuts of Duvall No. 1 are promptly harvested and dried in the fall, the kernels are almost white. Nuts that stayed on the ground 6 months during the winter of 1951-52 were harvested in late March 1952 and the kernels were still in good condition. Some of the nuts were on display at the Rockport meetings. Small size of nut is without question the chief undesirable characteristic of these trees. Duvall No. 5 produces the largest nuts of all the seedlings but they are so small that more than 100 are required to weigh a pound. Duvall No. 1 produces the smallest nuts and almost 200 are required to weigh a pound.

Past Yields: The one characteristic that sets these trees apart from all other pecan trees that we have observed in the Maryland area is that they yield heavy crops of nuts every year. We have known the trees only since the fall of 1951 but have observed two crops and Mr. Duvall has observed their performance for many years. In the fall of 1951 Duvall No. 2 yielded an estimated 8 to 10 bushels of nuts. Mr. Duvall harvested 3 bushels and he knew that 3 bushels were harvested by friends of the family. An unknown quantity estimated at several bushels was plowed under when wheat was sown shortly before we visited the tree in the fall of 1951. The tree had a heavy set of nuts in August 1952 and Mr. Duvall predicted that it would probably yield as much this year as last. He told us that the three oldest trees always have had annual crops of nuts except for 1 or 2 years when one of the trees failed to produce as much as usual. He could not remember which of the trees produced the light crops but he was certain that light crops were borne at only very infrequent intervals.

Sweeney Tree: The two nuts originally sent us by Professor Vierheller were produced by a tree growing approximately 200 yards from the nearest Duvall tree on a part of the farm recently subdivided and now occupied by a tenant named Sweeney. Mrs. Sweeney placed the plate of nuts on exhibit at the Prince Georges County Fair and from this plate Professor Vierheller procured the sample which he sent. Hence this tree has become known informally as the Sweeney tree. Its nuts are very long and pointed but in other respects resemble very closely those produced by the other trees. The Sweeney tree is undoubtedly a seedling of one of the three large Duvall trees. This tree also has an impressive yield record, as Mrs. Sweeney said that she has harvested a bushel or more of nuts from the tree every year during the ten or more years that she has lived on the place. In 1952 the Sweeney tree was bearing a heavy crop of nuts.

Soil: The trees growing on soil that is classified as Sassafras fine sandy loam in the heart of the southern Maryland tobacco growing district. This soil type, one of the best agricultural soils of the area, is not generally regarded as one of high fertility. This soil is well drained and aerated and friable to a considerable depth, thus permitting the trees to root deeply. None of the trees are growing under crowded conditions since they are located around the margins of the building sites of the old homestead. The question now is whether grafted trees propagated from the best of the Duvall seedlings will yield heavy crops of well filled nuts that will mature early under other conditions of soil and climate in other localities. We are inclined to believe that some or all of these trees may represent a line of pecan genetically constituted to bear heavy crops of nuts every year under conditions in Maryland. If trees propagated from the Duvall trees will perform elsewhere in the northern zone there will be available for this area a new type of pecan that we feel will be distinctly worthwhile notwithstanding the small size of the nuts. Present varieties of the so-called northern pecan grown in the northern zone perform erratically at best and when many of the varieties produce crops the nuts fail to mature and fill properly.

FOOTNOTES:

[Footnote 2: Horticulturist and Principal Horticulturist, Bureau of
Plant Industry, Soils, and Agricultural Engineering, United States
Department of Agriculture, Beltsville, Maryland.]

The Hickory in Indiana

W. B. WARD, Department of Horticulture, Purdue University, Lafayette,
Ind.

Mr. Charles C. Deam, forester, naturalist and botanist, in his book "Trees of Indiana," revised 1952, lists seven distinct types of hickory in the state and nine sub species. As Deam is approaching his 87th year (August 30), he makes this statement: "I thought I knew trees, and hickories especially, but at this time when I can hardly see and write I find there is a great need for reclassification." What is true in Indiana is no doubt true in other areas where Hicoria grows—each year new seedlings and hybrids are found that just step out of any previous description and a new tree may result or change the published data.

Some trees develop five leaflets, while others have seven and nine leaflets. The bark may be smooth, rough, scaly, or shag. The nuts will vary in size and form with a thin to quite thick shell. This, of course, applies to the seedlings as the grafted or budded varieties vary only with the location, season, and growing conditions.

The present classification, according to Deam, is as follows:

1. Carya pecan—Pecan.
2. C. cordiformis—Bitternut.
3. C. ovata—Shagbark and 2 sub species—fraxinifolia and nuttali.
4. C. laciniosa—Bigleaf Shagbark (Shellbark).
5. C. tomentosa (alba)—Mockernut—one sub species.
6. C. glabra—Pignut and sub species—Black Hickory.
7. C. ovalis—Small-Fruited Hickory and 5 sub species.
8. C. pallida }
9. C. buckleyi } —Minor species of lesser importance.

The hickory species thrive in Indiana, doing very well in all sections except in certain portions of the northwestern part of the state and on muck or sandy soils. The tree loves company or does well alone. When the hickory stands alone, the trees are well formed and make a good specimen tree. Many hickory trees are found growing in the river bottom land from Central to Southern Indiana with fewer trees found north of a line extending from Terre Haute through Indianapolis to Richmond. This southern area also contains the largest population of pecans. There are some woods that contain only pecan trees while a mile or so away no pecans are found but all are hickories and occasionally some woods contain both pecan and hickory. The trees in the woods areas, many of which seem to be the same species, produce a wide variety of fruits. When the trees are more closely examined there is a difference in the bark, the branch, the leaf, pubescence, shape of nut and shell structure. As there are all seedling trees in this particular woods, several outstanding trees have been checked and especially as to cracking qualities of the nuts. At harvest time a hammer is part of the equipment and the nuts are cracked at the tree and the tree marked for discard or further consideration.

Future Possibilities of the Hickory

The hickory nut has not reached the popularity of the pecan, although the hickory contains more protein and slightly less fat, carbohydrates, and calories per pound than the pecan. Where the pecan does not fruit, the better hickories, which are hardy, fill the need. The named varieties are good and trees are available from some nurserymen. The propagators have developed a few new crosses but man is far behind nature in this work. The many new seedling trees scattered all over the regions where the hickory grows require only propagation and distribution for wider acclaim.

The development of a new hickory is a long-time process, yet may be hastened by first planting the nuts for new seedlings and when the growth is mature to bud or graft the seedling on large rootstocks. When old trees have been top-worked it is only two or three years' time until the fruit develops and, if worthy of propagation, much time may be saved by this method.

Most of the hickories have either 32 or 64 chromosomes, except pecan which varies from 20 to 24 to possibly 32. The chances of making suitable crosses between the pecan and hickory are most difficult yet it appears that these chance crosses result from time to time as in the hican through natural cross pollination.

How extensive will be the plantings of the hickories is yet to be determined but it is a known fact that many people, especially north of the route of Federal Highway 40, prefer the hickory to the pecan. This may be due to the fact that from childhood the hickory was the local fruit. The fruit and tree hold great promise for the future. If the hickories are to be of commercial importance, the work must be done by all concerned and not left to a few eager individuals to carry on the work alone.

MR. MACHOVINA: Mr. Chairman, members of the Association, I hope you will bear with me if I run 30 seconds over. Perhaps I had better point out that my training is that of an engineer and not a botanist, hence this report on the Merrick tree is that of a layman. I have not bothered to go into detail on the various features of the tree, such as leaves, buds, and so forth, because I have slides which you will see afterwards.

The Merrick Hybrid Walnut

P. E. MACHOVINA, Columbus, Ohio

The Merrick hybrid walnut is a natural cross between Persian and black walnut and is distinguished from most other such hybrids by the good crops it usually bears. The tree is located in Rome Township, Athens County, Ohio, on property owned by Mr. M. M. Merrick a farmer and fruit grower.

In August, 1950, Mr. Merrick first described his "English" walnut to the writer and arrangements were made to view the tree. Most striking at first sight was the large crop of nuts. The general outward appearance of the tree suggested it to be pure Persian; however, upon closer examination, mixed parentage became evident. As a hybrid, the tree's history was a matter of interest and the owner was happy to supply what information he could.

Mr. Merrick purchased the property on which the hybrid is located, in 1921. A few years prior to this, the previous owner had planted six Persian walnut trees obtained from a nursery in northern Ohio. These young trees bore their first crop of nuts during Mr. Merrick's first year of ownership. It is known that the nursery owners were also proprietors of a commercial Persian walnut orchard located in the vicinity of Niagara Falls. With this combination of date and orchard location, it seems not illogical to presume that the six nursery trees were of the Pomeroy strain. From Mr. Merrick's description of the nuts produced by these trees, they appear to have been two each of three different grafted varieties. In the early nineteen-thirties, Mr. Merrick planted several nuts from the Persian trees and raised a number of seedlings. One of these seedlings, transplanted to its present location, is the subject of this discussion and is presumed to be a cross between one of the six Persians and a native black walnut. During the late nineteen-thirties, all of the trees, Persians and seedlings, with the single exception of the existing hybrid, were killed by an unusually hard winter.

The Merrick hybrid walnut, now about 20 years of age, is an extremely vigorous and healthy tree. Its height is between 55 and 60 feet and its spread nearly as great. Trunk diameter is at present about 12 inches at breast height. The location of the tree is very favorable, being near the crest of a high ridge and with protection from the northwest by the house. A chicken yard is near and the kitchen drain empties close by to supply moisture.

In nearly all aspects excepting the nut itself, the tree favors its pistillate parent. This is evidenced by the general shape of the tree, by the texture and color of the bark of limbs and twigs, and by the shape and color of the leaves, the buds, the flowers, and the nut hull. Hybridity is indicated by the (usually) eleven leaflets to the leaf stem, by the nut, and in the disintegration of the hull which, after falling, quickly changes into a most disagreeable, dark-brownish, semi-liquidlike mess. The nut itself is much more like a Persian walnut in appearance than a black walnut. The shell surface is slightly rougher and somewhat darker than most Persian nuts. The suture of the Persian parent is prominent. Black walnut parentage is exhibited by the thick shell, the interior configuration and in the flavor of the small kernel. Nut size varies somewhat with diameters ranging from 1 to 1-1/4 inches and lengths ranging from 1-1/4 to 1-1/2 inches.

The bloom, which is strikingly like that of pure Persian trees, is always profuse and precedes that of the surrounding native black walnuts by a week or two. In the two years during which the writer has observed the tree, the greater part of the staminate bloom has preceded the pistillate by several days. This was noticeably the case during the current year, and either this, or the rainy weather, has resulted in a small set of nuts which the owner states to be unusual. During the years observed, the tree appeared to be self-pollinating.

It is recognized, of course, that the Merrick hybrid is worthless as a producer of edible nuts. The possible value of the tree lies in opportunities it offers in being the forbearer of more worthwhile progeny. We know of the vast possibilities in hybridization. We know of the difficulties involved in obtaining nuts from controlled crosses between Persian and black walnut trees; and we know that seedling trees raised from the nuts of such crosses are almost always sterile. The Merrick hybrid, yielding good crops, offers possibilities both in crossbreeding and in the raising of seedling trees from the nuts of the tree itself. In the latter connection, Drs. Crane and McKay, of the U.S.D.A., requested several pounds of Merrick nuts for planting purposes this spring. The writer himself planted five such nuts, of which four germinated. Of the four trees, one died early in the season, while the remaining three have thrived. The heights attained by the three remaining trees thus far this season are 1, 2, and 3 feet, respectively. These trees have the general appearance of young Persian seedlings.

The only crossbreeding attempted thus far ended in failure when a storm destroyed most of the bags prior to application of pollen. Persian pollen was used on the few bloom remaining covered but, unfortunately, no nuts were set. The experiment will be continued. Also, the Merrick will be topworked onto producing walnuts, both Persian and black, in the hope of obtaining nuts from which interesting and perhaps better second generation hybrids can be raised.

An interesting point of conjecture on which to terminate this report, and one to which nut experts will likely give little credence, may be found in a statement made by Mr. Merrick and vouched to by Mrs. Merrick. The statement is to the effect that the nuts borne by the Merrick during its early years, that is, prior to the time the adjacent Persians were killed, were of much better quality, being more like Persian walnuts both in appearance and in flavor. We've heard of "pollen influence" with chestnuts. Did it occur here?