Black Walnut Notes for 1933

By C. A. Reed, Associate Pomologist Fruit and Vegetable Crops and Diseases U. S. Department of Agriculture

A number of developments in connection with the black walnut industry of the East have taken place during the last 12 months which appear to be of such importance as to justify special record at this time. Some of these have to do with the production and marketing of and prices received for, the wild product, others with certain features in connection with orchard and nursery management, and still others with walnut relationships both inside and outside of the genus.

The Black Walnut Kernel Industry

Production of black walnut kernels in this country is fully 99 per cent from seedling trees of the fields, forests, roadsides and dooryards. That from orchard and top-worked trees, while now considerably on the increase, due to recent activity in planting and top-working, will hardly become of relative importance for some years to come. The wild crop is actually on the increase each year, due partly to greater care now taken of old bearing trees and partly to the large number of young trees coming into bearing each year but more largely to the greater extent to which nuts are now being gathered and not allowed to decay on the ground.

This increase in production is working both for and against the permanent welfare of the industry, and by this use of the term "industry", it is meant to include the cultivated as well as the uncultivated phases. Consumption has increased tremendously. No figures are available as to either total production or percentage of total crop which is still allowed each year to remain on the ground until it becomes decomposed.

However, it is the opinion of Baltimore merchants who have long handled this product that in certain large districts the wild nuts are now gathered closely and that very few are allowed to decay on the ground. There is no available information upon which to base a curve as to the probable increase in production which may be expected from young trees just beginning to bear or the thousands still too young to bear or yet the other thousands to be planted by squirrels each year. Whether or not the increase in consumption and its coincident change in eating habits of the American people will prove permanent after the return of normal times, remains to be seen, but it may be accepted as fact that the future of this country is likely to see greater competition in the home markets among foods than has been the case in the past and that, eventually, only those having the greatest values in nutrition and palatability will survive. Salesmanship may defeat this for a while but ultimately, palatability assumed, cash values and human tastes will most certainly arrive at pretty much the same point. The ultimate future of the walnut would therefore appear to depend largely upon its ability to become one of the fittest survivers.

One of the most important developments during the past year is of very recent occurrence. It is the fact that the 1933 season is opening with the highest prices received during the last two years. This may in part be due to reports that the outlook in the Tennessee—Kentucky—Virginia and North Carolina district is for a light crop. According to Baltimore merchants who have recently been consulted, consumption last year was the greatest in history and, while prices reached the lowest level since the depression began, relatively speaking, the total drop has probably not been as great as for other food products during the same period. These merchants look forward with confidence to a continuance of increased consumption.

This forecast is encouraging, but it is based on the assumption that there will be continued improvement in the manner of handling and packing the kernels for delivery. At present, considerable overhead is usually charged back to the farmers because of labor involved in cleaning, grading, and sometimes curing, after the kernels reach the city merchants. This handling is necessary with much of the output in order that it may be made acceptable to the manufacturers. One of the most desirable characteristics in connection with the sale of black walnut kernels is brightness of color. This is a matter largely due to the manner of handling during the process of harvesting, curing, and cracking. Once the kernels become dark, they cannot be brightened except by bleaching and removing the pellicles. However, the importance of prompt gathering as soon as the nuts fall from the trees, removing the hulls, and curing the nuts cannot be overestimated. These are matters easily within the ability of the producers to adjust.

The Orchard Industry

On the orchard side of the industry, several developments may be listed, although the majority are merely old developments newly emphasized.

Black walnut trees, seedlings and grafted trees alike tend to bear full crops not oftener than during alternate years, and with conditions at all unfavorable, full crops may be delayed for several years.

Grafted trees of many varieties begin to bear their first fruits quite as promptly as with apples. Not infrequently walnuts appear by the end of the second year after grafting. This is especially true with top-worked trees.

Recent Adverse Weather Conditions

The spring and summer season of 1933 made an adverse combination in some localities. In the Ohio and Mississippi River Sections, the result was disastrous to a large part of the crop. In those sections, May was an exceedingly rainy month. June was equally hot and dry. It is in May that the blossoming periods of most varieties of walnut occur, also it is then that most of the nursery grafting is performed. Insofar as pollination was concerned, there were probably enough hours of sunshine during the blossoming period for the distribution of pollen to have been adequate and effective. On some of the trees the rains came at just the right time to wash practically all of the pollen to the ground. Had it not been for later pollinating trees either of the same variety, or of other varieties, or even of seedlings in the neighborhood, it is probable that no nuts would have set. However the actual set was about normal, but the heat and drouth which followed resulted in a drop which took the greater part of the crop. A pecan grower in southwestern Indiana, with between 300 and 400 grafted trees now of bearing age, recently reported that in August he was unable to find a single nut in his entire orchard. The result has not been quite as serious with the walnuts. Nevertheless, the crop prospects are reported to be not at all bright.

Nursery grafting in southern Indiana had literally to be performed between showers. Sap flow was excessive and the resulting stand below normal. The heat and drouth which followed killed outright many of the scions which had begun to grow. Thus, in that section the orchardists lost most of their crops and the nurserymen most of their grafts.

Walnut Relationships

In regard to walnut relationships within the genus, continued studies have led to certain conclusions which would appear to bear mentioning. One of these is to the effect that not all so-called "butterjaps" appear to owe their origin to staminate parentage of butternut but that they may be due to chance crosses of either Japanese walnut with Persian or possibly black walnut, or quite as often to reversion to the true Manchurian walnut, Juglans mandschurica.

Hybrids and Intermediate Forms

It is generally known that natural hybridity occurs so frequently between almost any two species of Juglans when growing together and blossoming simultaneously that it is unwise to plant the seed of either if pure types are desired. Intermediate forms, evidently between Persian (English) and black are fairly common throughout the East. The James River and O'Connor hybrids are well known typical examples. Such hybrids are most apt to occur in vicinities of Persian walnut trees. Crosses in which the Persian walnut is the staminate or pollen producing parent may sometimes occur but if so, they have never come to the attention of the writer. Crosses between these two species commonly have the Persian walnut as the pistillate or nut producing parent.

The most commonly seen forms which appear to be due to hybridity are in the case of certain Japanese walnut seedlings in the East. The offspring of these trees frequently takes on much of the character of the American butternut. Nuts of this type have been recognized by this Association and other authorities as "butterjaps." In his Manual of American Trees, Dr. Albert H. Rehder of the Arnold Arboretum, Jamaica Plains, Mass., recognizes crosses between the Japanese walnut and American butternut under the technical name of Juglans bixbyi after the late Willard G. Bixby of the Association by whom the matter was called to his attention. However, it is not certain that nuts definitely known to represent a cross between these two species have yet been brought to notice.

Butterjaps

It has been commonly assumed that nuts of the butternut type, from trees grown from Japanese walnut seed are due to butternut hybridity, but the theory is clearly open to reasonable doubt. Nuts of this identical type are common in the orient where the butternut does not occur and also they sometimes occur in this country on trees grown from imported Japanese walnut seed. The late Luther Burbank wrote the Department of Agriculture in 1899 that in California where he had grown many thousands of seedlings from both imported and California grown seed, he was unable to detect the slightest differences in foliage, yet the trees were apt to produce nuts of any one of three types then known as Juglans sieboldiana, J. cordiformis or J. mandschurica. He wrote that "They all run together and are evidently all from the butternut family."

An authentic case of butterjaps from imported seed was made public during the first annual meeting of the Pennsylvania Nut Growers' Association which was held in Harrisburg on January 11 of this year. Butterjaps were on display during that meeting which had been grown by Mr. Ross Pier Wright of Erie, Pa., from seed which he had imported directly from Japan. His trees are growing in the outskirts of Westfield, Chautauqua County, N. Y., and within a mile of Lake Erie.

In July of this year, Dr. E. A. Scott of Galena, Md., called the attention of the writer to a number of fine trees in his small town, all of which had been grown by him from J. sieboldiana seed obtained from a tree nearby and "every one" of which was bearing "butternuts," as he and his neighbors call them. The American butternut does not occur in that part of Maryland which is on the upper end of the Chesapeake Peninsula, probably 10 miles from Chesapeake Bay. Both black and Persian walnut trees are very common in that region. The tree which bore the original seed is a typical Japanese walnut. It stands at the end of a row of Persian walnut trees along the driveway of a private country lane. There are several black walnut trees, perhaps 500 yards to the southwest, but no butternuts for many miles. As the Persian and Japanese walnuts blossom at about the same time and the black walnut considerably later, it would seem altogether probable that if any cross had taken place it would have been Japanese x Persian, rather than Japanese x black. The chances of a Japanese x butternut cross would have been so remote as to be altogether improbable.

Many years ago, Judge F. P. Andrus of Almont, Mich., planted one tree each of Persian and Japanese walnuts in his dooryard. Both soon came into bearing. Squirrels planted nuts in the ground and presently the yard was filled with offspring, the majority of which were of the type now called butterjaps. The trees were extremely vigorous but the nuts were of so little value that all were finally cut down. Butternut trees are common in Michigan and butternut pollen may have been responsible for these crosses but circumstantially the evidence pointed much more strongly to Japanese × Persian crosses than to Japanese × butternut crosses.

Other cases of these sorts might be cited, but the evidence which the writer has been able to bring together up to the present month, September, 1933, strongly indicates that butterjaps may be due to either an actual cross with a Persian or black walnut and possibly with butternut or to reversion to a parent oriental type. So far, it has been out of the question to hazard a reasonably safe assumption as to the staminate parent of all particular crosses by merely studying the botanical characteristics of the butterjap offspring.

Several years ago Mr. Bixby planted a number of butterjap seed nuts, hoping that under the Mendelian law, the characteristics of the two parents would segregate themselves. The trunk and bark of some of the trees resembled black walnut quite distinctly, while none resembled the butternut. So far as is known to the writer, none of the trees have yet fruited. One of the several butterjap trees in Galena, Md., previously referred to, produced nuts rather more like black walnuts than butternuts. These two instances therefore, would suggest Japanese × black walnut parentage.

Black Walnut Root Toxicity

On several occasions discussions of root toxicity between the black walnut and certain of its neighbors have taken place at Association meetings. The theory that black walnut trees give off toxic properties from their roots, which are fatal to other plants, is therefore not new. Some years ago the Virginia Experiment Station definitely isolated a toxic substance which was held responsible for the death of tomatoes, potatoes, alfalfa, blackberry plants and apple trees when these other plants were grown in close enough proximity for their roots to come in contact with those of the black walnut. This work was reported in various publications and was written up by several different authors.

Since then, as well as before, the writer has looked for similar evidence, but, so far, in vain. Each of these crops, including tomatoes, potatoes, alfalfa, blackberries and apples, have been seen growing in as close contact with black walnut as they could possibly be placed. Oftentimes they have been found much nearer to black walnut trees than would have been wise to place them to oak, hickory, ash or other species of large growing trees. This does not mean that when the roots are in actual contact the toxic agent of the black walnut roots would not prove fatal to the other plants but it does indicate that in the great majority of cases there is no practical danger.

Anyone who has doubt about the healthy condition of these other species when grown close together with black walnut trees, may obtain evidence for himself by noting the frequent combination of this sort easily found in fields and gardens of the country and small towns. It is surprising how often these combinations of black walnut and other species are to be seen. Any unprejudiced person could hardly fail to become convinced that, in the great majority of cases, the danger is of small practical consequence. The roots of the black walnut run deeply under ground and it is entirely conceivable that in deep soil they do not ordinarily come up to the shallower levels of the roots of most other species.

Summary

A summary of the year's developments might be arranged about as follows:

(1) More black walnut kernels were harvested and consumed during the year than ever before.

(2) Prices to the farmer reached about the same low level of the year preceding, but the total drop during recent years was probably not in proportion to the drop of most other food products.

(3) Crop prospects in 1933 are unfavorable for another large crop. Prices are starting out considerably higher than for several years.

(4) Production of black walnuts from grafted trees under cultivation is altogether insignificant in comparison with that from chance seedlings receiving no special cultivation.

(5) Grafting and planting are taking place at too moderate a rate to materially alter the ratio of production from seedling to that of grafted trees in the near future.

(6) There has been considerable improvement during recent years in the manner of preparing and packing black walnut kernels for market, but there is need for further advance along this line.

(7) Merchants engaged in handling black walnut kernels predict that there will continue to be a normal steady increase in consumption, now that the market has become established, trade channels opened up, and consumers habits somewhat established.

(8) Walnut hybrids occur frequently in nature. So far, none have appeared which were of special value because of the character of nuts which they produce. So-called butterjaps appear to be possible from either certain crosses or from reversion to parent oriental types.

(9) Ordinarily, other crops may be interplanted with black walnuts with as great safety as with most other equally large growing and deep-rooted trees.