Part 11

Regarding the susceptibility to the blight of the European or Spanish Chestnut (_C. sativa_) we have had the following experience. Our winter temperatures appear to be too severe for this species. Dying back is sure to occur, at least at our Hamden, Connecticut plantations, marked more or less according to the degree of cold; and on the dead parts _Endothia_ then appears, to later invade the parts still living. In 1932 I received nuts of _C. sativa_ from France from Professor Hochreutiner of the Geneva Botanic Garden, from Professor Uldrich of the Berlin Botanic Garden, and also from France from Dr. Guillaumin of the Jardin de Plantes at Paris. Although I have given the resulting plants much attention they continually die back each year so that we have only two or three individuals that are more than six feet high. But Professor Pavari says in recent correspondence (July 15, 1947) "Referring to Spanish chestnuts, after we have been assured that the fungus we have found and observed on _Castanea crenata_ in Spain is really _Endothia parasitica_, we must admit that our hypothesis may be exact that _Castanea vesca_ [_sativa_] presents in Spain races or types resistant to the disease." He goes on to say that the fact that the chestnut blight is so widespread at Naples and Avellino is at variance with my theory that cold winters are the predisposing cause, for in the regions mentioned the winters are mild and "very warm in comparison with those of Connecticut." The essential fact seems to be that the European or Spanish chestnut is very susceptible to the blight, perhaps as much so as is our native species, but that evidently certain individuals or races exist that are more or less resistant.

During the early part of 1947 we had a visit from Professor Cristos Moulopoulos of the University of Salonika, Greece. Although the disease had not then appeared in Greece, the pathologists there would like to be ready for it when it does come.

_Pollinations in 1946 and 1947._ Without going into details, the general purpose of the pollinations during these last two years has been to incorporate more and more of the resistant Chinese stock into our hybrids. Beginning in 1937, we crossed our best Japanese-American hybrids with Chinese, and we now have a considerable number of young saplings of flowering age, which have the pedigree: Chinese x Japanese-American. Unfortunately, in this cross the Chinese is usually dominant as regards habit, but not always. We have some tall, straight-growing individuals of this combination which may well be the forerunners of a blight-resistant forest stock for America.

Therefore, during 1946 and 1947 we have been crossing these fine Chinese x (Japanese-Americans) with the following:

1. Our best Chinese 2. American-Chinese and Chinese-American 3. American (C. dentata) 4. Our best Japanese-Americans 5. Among themselves

For it is the ultimate aim of this work to develop a race of tall, hardy, blight resistant individuals which will breed true and thus of themselves re-establish the chestnut tree in the forests of Eastern North America. As everyone knows, the re-establishment of the chestnut as a forest tree can not be done in a few years or even a score of years, but by continued breeding and patience and perseverance it can be done. The materials are at hand, i.e. tall, erect growth, and blight resistance; and with persistent effort the desired combination can be made.

For (1) above we were fortunate in 1946 in receiving a supply of pollen from tall-growing Chinese trees, through the kindness of Mr. Michael Evans of Greenville, Delaware and Professor Maurice A. Blake of the New Jersey Agricultural Experiment Station.

As a result of our pollinations in 1946, in which 72 combinations were made, we harvested and planted in our cold frames in October 479 hybrid nuts, a large proportion of which germinated, so that this summer (1947) we have set out in our nurseries about 325 hybrid seedlings.

In 1947 we have made 58 combinations in which 213 branches were bagged; October 10-13 we gathered 380 hybrid nuts resulting from these cross pollinations. The large yield of 1947 is doubtless the result in part of a good growing season, for there was plenty of rain--at times almost too much--in southern Connecticut. One drawback was the cold period during the latter part of June. From the fifteenth to the twenty-sixth the minimum temperatures were 55 or below--on three days as low as 50. This set back the flowering period four days to a week later than usual, depending upon the species or hybrid.

_Cooperation in Diller's Underplanting and Girdling Method for the Establishment of Chestnut Forest Stands._ In the 37th Annual Report of our Association for 1946 is printed a paper by Dr. Jesse D. Diller of the Division of Forest Pathology, U.S.D.A. entitled "Growing Chestnuts for Timber" pp. 66-68. Many people seem to think that all you need to do when planting a tree is to stick it in the ground--just _any_ ground. This may be true of some kinds, but is certainly not true of the chestnut. For best growth and development the chestnut requires a fairly deep, well-drained soil, rich in mineral elements and humus, with a fair degree of moisture and plenty of sunlight. Two things chestnuts will _not_ endure are shallow soil and drought, the latter often depending on the former.

As tree indicators of the kind of site required for the establishment of a chestnut forest Dr. Diller has chosen yellow poplar, northern red oak, white ash, sugar maple, and yellow birch, with spice bush as a shrub indicator and maiden hair fern, bloodroot and other herbs as herbaceous indicators. Using a small area of about one eighth of an acre, Dr. Diller's plan is to girdle all the trees and then underplant with chestnut seedlings. He says: "As the girdled overstory trees die they gradually yield the site to the planted chestnuts in a transition that does not greatly disturb the ecological conditions, particularly of the forest floor. Rapid disintegration of the mantle of leaf mold is prevented by the partial shading which the dead or dying overstory, girdled trees cast." This may seem to some a rather drastic method, but when so much is at stake, namely the re-establishment of the chestnut in our forests, it would seem a justifiable experiment on a small area.

In March, 1947, we supplied Dr. Diller with one hundred seedlings, one or two years old, of our best stock, for underplanting in two of these selected sites, fifty seedlings each, namely on the estate of Mr. E. C. Childs at Norfolk, Connecticut, and on lands of the T. V. A. at Norris, Tennessee. Our best wishes for a successful blight-resistant future go with these little trees.

_Grafting Work._ We are continuing with our method of "inarching" young "suckers" from below a blighted area into the trunk above the lesion, the diseased tissue of the lesion being first cut out. This method (see Brooklyn Botanic Garden Chestnut Breeding Project. 35th Annual Report of Northern Nut Growers Association for 1945. pp. 22-31--1945) is entirely successful in case we desire to preserve partly resistant hybrids of good parentage for future breeding and for scions. (Figs. 1 and 2) But inarching of the native chestnut is for the most part unsuccessful because the fungus grows too rapidly and girdles the stem, killing the parts above before the inarched tips of the suckers can take hold. There seems to be a certain relation between the amount of disease resistance in the tree and the possibility of restoring it to health by the inarching method.

By the common ordinary cleft-graft method, using Japanese, or better, Chinese stock we are adding to the supply of our most desirable hybrids.

_Insect Pests._ The spring canker worm, _Paleacrita vernata_, has not been destructive either in 1946 or 1947 and no special preventive measures have been taken. Japanese beetles have done a little damage. This year the first one appeared July 11. We find the best method with these is to pick them off at dusk after they have settled themselves for a night's sleep, dropping them into kerosene oil. Under these conditions they will usually slip readily off the leaf into the oil. One thing I should like to emphasize (which probably others also have noticed) is that new beetles keep coming, day after day. Apparently the adults are issuing from the ground all summer. Last year I found a few Japanese beetles in November. So one must keep continually on the job all through the season. This summer (1947) we have had a spray program of three sprayings, August 15, 30, and September 10, with "Deenate" (fifty percent DDT) to destroy the chestnut weevils which appeared for the first time rather extensively in our Hamden plantations last year. (See E. R. Leeuwen; DDT for chestnut weevils, American Fruit Grower 67: 28. 1946) This spray, which we have used on the ground as well as on the young burs, kills Japanese beetles as well as the weevils. This fall I have seen very few weevils in our whole crop of nuts.

The louse, _Callaphis castaneae_, appeared on July 5, 1947, at least the leaves became so much curled that its presence was then noticed. Two spraying on successive days with nicotine sulphate ("Black Leaf 40") were sufficient to control it. With us this insect attacks leaves of American stock only. Japanese-American hybrids are also susceptible, but not Chinese-American or American-Chinese. The lice, of an orange color, congregate in great numbers along the midrib of the leaf, sucking out its juices.

This summer, perhaps on account of the unusual almost tropical weather conditions--hot and humid with continually recurring showers--we have been harassed by a new pest which has appeared in one of our plantations only sparingly for five or six years--a mite, which Connecticut Agricultural Experiment Station authorities say is _Paratetranychus bicolor_. Affected leaves have a whitish or grayish color chiefly along midrib and principal veins, due partly to the deposit of the creature's shells on molting, and partly to injury to the tissues of the leaf. Hexa-ethyl tetraphosphate, known in the trade as "Killex 100," was used effectually twice as a spray. Unfortunately this chemical has no ovicidal properties, so that a second spraying was necessary to kill the mites newly hatched out from thousands of eggs. We are informed that DN 111 will kill the eggs as well as the mites and will kill aphids at the same time. The mites seem to prefer Chinese chestnut leaves, but this summer they didn't seem particular and spread from one badly infested tree as a center.

[Illustration: Fig. 1--Japanese-American hybrid chestnut (Hammond 86-31) 34-1/2 feet in height, 16 years old. This is the same tree three years later as that shown in figures 1 and 2, in 35th Ann. Rept. of Northern Nut Growers Assoc. for 1944. Note healthy development, as shown by foliage and long yearly growth. Hamden, Conn. Photo. Sept. 13, 1947 by Louis Buhle.]

_Chinese Chestnuts._ I am enthusiastic about Chinese chestnuts as a nut substitute for our old native chestnuts. The Chinese are quite blight resistant. They are attacked by the blight fungus--at least most individuals suffer at some time in their lives, and yet the fungus doesn't thrive and the trees are able to overcome its attacks, in many cases forming a healing wound callus around the lesions; in others the lesion becomes simply a granular mass in which the fungus appears to be living only in the outer bark. Cultivation, fertilization, and judicious pruning certainly help these trees to withstand these fungus attacks. We harvested a bumper crop last year and this from trees given us in 1929 by the Division of Forest Pathology, U.S.D.A.

[Illustration: Fig. 2.--Close-up of lower part of tree in fig. 1, showing inarched basal shoots which at the beginning were as slender as the leafless shoot now showing on right side, below, coming from base of trunk. Note exposed dead part of trunk showing old canker disease. Photo Sept. 13, 1947, by Louis Buhle.]

_Public Interest in the Problem._ Last fall, September 1946, in an article in the Yankee Magazine, I asked for nuts and pollen of the American chestnut. As a result the following persons from many different parts of the country sent in nuts: Mr. Henry Hartung, Methuen, Mass.; Mrs. Marie Garlichs, Brooklyn, from Lake Minnewaska, N. Y.; Mr. Charles Ericson, Brooklyn, nuts from Staten Island, N. Y.; Mrs. Jay B. Nash, N. Y. City, from Lake Sebago, Sloatsburg, N. Y.; Mr. H. W. Donnelly, Tacoma, Wash.; Mr. George M. Hindmarsh, Kent County, R. I.; Mrs. Steiner, Niota, Tenn.; Miss Marjorie Bacon, New Haven, Conn. from Litchfield, Conn. through Dr. Edgar Heermance; Mr. Harold E. Willmott, Bethel, Conn.; Mr. W. F. Jacobs, Tallahassee, Fla. (_Castanea crenata_); Mr. P. P. Pirone, New Brunswick, N. J. (_C. crenata_); Mr. Morton F. Sweet, Seattle, Wash. (_C. sativa_), nuts, and scions in March '47; Mr. John I. Shafer, Sparta, Tenn. This lists shows not only the widespread interest in the subject but also that the chestnut sprouts are still bearing nuts. In some cases the nuts were "blind," i.e. sterile, containing no kernel or embryo. In order to develop a good nut there must be two chestnut trees within a reasonable distance of each other so that cross fertilization may take place. Isolated trees will usually not bear nuts. In other words, the chestnut is usually self sterile. We are still planting all nuts received, labeled with the name and address of the sender. The resulting trees are being set out in the Yale Forest in Tolland and Windham Counties, Conn. under the direction of Mr. Basil Plusnin, Forester in charge. Thus the possibility is being explored of the existence of blight resistant strains of the American chestnut. When nuts are sent they should be mailed within a few days after harvesting and wrapped in moist cotton, peat moss or something similar. Drying of the nut kills the embryo so that it will no longer germinate. Nuts should be mailed to me at Chestnut Plantations, Wallingford, Conn.

Pollen of the American chestnut is getting scarce. After scouring the vicinity of Hamden, Conn. this summer, we found a good supply at Bethany, Conn. from native shoots. The following persons also sent us American pollen, for which we are indeed grateful: Mr. George Gilmer, Charlottesville, Va.; Mrs. M. E. Garlichs, Lake Minnewaska, N. Y.; Mr. Alfred Szego, Pine Plains, N. Y.; Mr. Seward Pauley, Sumerco, W. Va.; and Mr. Charles W. Mann, Fennville, Mich. To ship the pollen it is necessary only to wrap small branches bearing the catkins in oiled paper and mail to me, preferably by air mail. The catkins should be ripe, i.e. shedding the pollen.

_Acknowledgments._ It is a pleasure to have this opportunity to express our appreciation of the cooperation of the above mentioned persons. The interest of these and many other persons and institutions is encouraging. During 1946 and 1947 this project has been sponsored by the Connecticut Geological and Natural History Survey, and we have as usual enjoyed the cordial cooperation of the Division of Forest Pathology, U.S.D.A. Dept. of Agriculture.

Beginning as of October 1, 1947, the work is also being sponsored by the Connecticut Agricultural Experiment Station, New Haven, Conn. On July 1 I retired from my position as Curator of Public Instructor at the Brooklyn Botanic Garden and shall now be able to devote my entire time to the chestnut work. My permanent address will be: Chestnut Plantations, Wallingford, Conn.

Chinese Chestnuts in the Chattahoochee Valley

G. S. JONES, Route 1, Box 140, Phenix City, Alabama

(Excerpts from letter to Secretary, Oct. 23, 1947.)

Growing trees is a work dear to my heart for I have been interested in it since childhood. Dr. J. Russell Smith's book on "Tree Crops" is one of the best I have ever read along the lines of growing trees to produce food for man and beast as well as producing many other useful products, and much of the work of your Association seems to be along the same line. I am sure we can live easier and better on this earth when we learn to use the trees in their proper place. Man often acts in a shortsighted way by depending largely on annual crops for the main source of food for himself and his animals and neglects the long lived trees which may not have to be planted but once in a lifetime and which, if given a little intelligent management, will improve instead of deplete his land and at the same time make a far more beautiful landscape.

I only have a few trees (maybe 200 or 250) in my nursery which I usually dispose of at the farm or use to set on my place. I have not attempted to grow many seedlings as I don't wish to get into this phase of work. It would take too much time from other work which I like to do. This fall I have sold over 600 pounds of nuts to various nurseries for planting so I would prefer that they grow and sell trees from my orchard. I gather planting nuts from the trees which show the best qualities, consistently, and sell the nuts from the other trees for eating purposes. The trees from which I sell eating nuts have some bad qualities such as some of the nuts being retained in burs, irregular or poor production, and nuts that seem to be too dry at ripening so I would not offer these for sale although the pollen from these trees does mix with the others causing some of the nuts to carry these bad features, a thing which will hardly be avoided in open-pollinated seedlings.

Your letter made me more proud of my orchard than ever when you made the statement that my last year's production of 1,722 pounds for 22 trees so young as mine may have set a record for production. [See 1946 NNGA Report, p. 128--Ed.] I had little idea how my trees compared with other orchards, for Mr. Gravatt had not told me anything about this. In fact I have never seen him nor did I take the trouble to write and ask this question. I knew my trees were producing much better than an orchard of the Soil Conservation Service at Auburn but I attributed that to the better type of soil (for chestnuts) in which my trees are set, and better air drainage. I had also heard about an orchard near Blue Springs above Columbus, Ga., which was not doing so well because the soil was maybe too heavy or damp. I can say one thing and that is that my Chinese chestnuts have surely surpassed my fondest hopes and dreams, for that small area has certainly made me lots of money and has given me much joy in tending it and watching it grow.

You asked me to give some information about my 1947 crop. This has not been quite as large as last year as I have harvested only a little over 1,554 pounds (I say a little over for it is hard to get all the nuts) of weighed nuts. This includes some that were beginning to spoil. I include these since it is sometimes due to my failure to gather promptly and I think can be fairly included in production records. I might state here in fairness to last year's report of a yield of 1,722 pounds of nuts that I recorded 1,557 as being sold which leaves a difference of 165 pounds, which were either discarded as spoiling or were unaccounted for. This gives me a loss of approximately 10% for last year.

Although my total production was lower than last year I had one tree (ML No. 2) which produced 150 pounds of weighed nuts and a few pounds more (maybe 2 or 3) which were not included. This tree has been a consistent heavy bearer for several years but I had not checked its yield separately before. Since it is so early it was easy to keep the nuts separate (as I was keeping these to sell for seed nuts). In about 2 weeks time it had produced about 130 pounds so I made a special effort to check the remainder since I was astonished at so large a yield. When most of the nuts had fallen I had the above figure, to my surprise.

The tree in size is not my largest but about average being 12-1/2" in diameter 3' above the ground with a limb spread of 30' and a height of 24'. It has a very symmetrical shape with enough rigidity in the limbs to hold them off the ground so the tree does not appear very large.

I just had to laugh when I got a letter yesterday from Mr. Ralph D. Gardner, whom I had written previously about the yield of this tree and sent 2 pounds of nuts from it, asking me if the tree produced two crops in one year. He said Mr. James Hobson had told him that he gets two crops from his tree each year. Mr. Gardner had a good reason to ask this question since knowing about the Hobson chestnut, but I reckon he might have thought about what I would have thought under similar circumstances, i.e., surely a tree so young (13-1/2 years from setting) couldn't produce that many nuts at one time, so must have two ripening periods to contain the fruit. I will have to say that all these were produced in one crop. Most of these ripened in just a little over two weeks. I might say that I do have one tree (ML No. 1) which has on a few occasions bloomed the second time and had burs which remained green until near frost but these did not amount to anything and I consider it undesirable. I have never seen No. 2 tree produce late blooms and burs.

I might tell a few things as to how I handle my nuts. As is well said by Mr. Reed in his 1946 article about chestnuts they should be gathered daily (although I sometimes don't carry this out). After weighing I dump the nuts in a tub of water. The nuts which are beginning to spoil will practically all float and the sound nuts will sink. This is where the largest percentage of my culls is eliminated. Some good nuts will float but very few if the nuts are gathered daily. I then put 20 to 25 pounds of nuts in a coarse mesh burlap bag. I use chicken scratch feed bags mostly as these are a nice size, and ties a string near the top of the bag. Then I place these on a lath frame which is about 12" above the ground under a large pecan tree which furnishes shade about 3/4 of the day. I arrange the nuts in the bag so it will be flat, which does not allow more than 2 or 3 nuts to be on top of each other.