Pith: Pith in the black walnut is chambered (lamellate) in the older wood, but solid in the younger, growing wood. The plates are a light brown color, getting larger in diameter toward the top of the year's growth. The leaf traces from the leaf rachis to the pith show heavier from the bottom buds of the branch than at the tip, and the pith is usually solid at the bottom of the branch.

Roots: When the nut of the black walnut germinates in the soil the lobes or cotyledons do not rise above the ground like the cotyledons of the bean but remain in the nut shell under ground, and are broken off in the growth of the seedling, the root going down and the stem rising above the ground. Where the cotyledons are broken off, the so-called crown of the walnut, two rough places appear, nearly opposite on the stem. In these rough places, two groups of buds are formed, rarely three groups.

Cytological studies at Iowa State College have not shown why there are not stem initials in the tap roots of the walnut. When the root is cut off a foot underground, root initials develop but no stem initials. The sensitivity of walnut leaf buds to water may have something to do with it.

Buds: Buds of the walnut are in vertical groups of two or three in the axils of the leaves. They have few scales. They appear on seedlings and current year branches. Some have short stalks. If broken off they do not usually grow back again. The second year, these buds usually drop off in mid-season. In cutting off buds, unless the group of buds is taken out as a chip, some may grow out again.

Leaf arrangement: There is a three rank arrangement of leaves in the walnut, the ninth leaf coming in the same position as the first. According to the work of Caesalpino, the buds should then rise in three places at the crown. Only in rare cases does this occur in the black walnut, although it is usual with the Persian walnut. If the nut is planted deep this causes much suckering and a tendency to etiolate the buds so they will stand water.

Buds are sensitive: Buds are sensitive to water, and storage material must be fairly dry and cool. In two large boxes of scions received last year from Germany, some 20 varieties of Persian walnut, all had dead buds when received. They were packed in German peat. When buds are covered with wax the wax must not be too hot or it will kill the buds. In placing grafted walnuts in sphagnum or sand they should not stay wet or the buds will die. Either unions must be above damp sand or sphagnum, or the buds be protected by wax or adhesive.

Sap: In spring grafting there is an enormous flow of sap which will sometimes tear the plates out of the pith. Grafts may be protected by girdling the stock a few inches below the place where the graft is set, or both above and below it. In 1937 259 walnuts three years old were cut off six inches above the ground and girdled two inches above the ground. 171 crown buds came up, 88 started above the girdling. 207 trees were cut off three feet above the ground, and the trunk girdled six inches above the ground. 153 started above the crown, and 90 started above the girdle. The same year (1937) 195 trees three years old were cut off four feet above the ground, and all buds above ground were cut flush with the surface of the bark. This was repeated twice, finally taking buds out as a chip, except the top bud; 126 died; 69 grew from the top but. 203 trees three years old were cut off five feet above ground and all buds cut off except upper one; 64 died; 139 grew from top bud. 200 trees three years old were cut off six feet above ground, and all buds kept rubbed off except top one; 33 died, and 167 grew from top bud.

Vitality and sap: Black walnut sap changes color from oxidation almost instantly. Bench grafts must be made quickly and put in place at once or the unions will dry out. If the root does not stain hands in grafting the graft usually fails. In outdoor grafting if the sap stands in pockets the sugar will ferment, killing the graft. There is a new Jersey (3) bulletin which shows black walnut sap as unstable, quickly forming sugar when exposed to warm weather.

Vegetative propagation of greenwood cuttings: Witt and Spence (4) in England working with greenwood cuttings attained 75 per cent success with Persian walnut and Royal walnut in July and August. They had no success with black walnut at that time (1926). The Germans in 1936 (1) working on greenwood cuttings had most success with the Persian walnut, but used greenwood taken in September.

Vegetative propagation or hardwood cuttings: In 1938 the author (2) using growth substance on saddle grafts of various walnuts found Asiatic and western walnuts went on their own roots. At this time the Tasterite black walnut went on its own root. In 1946 and 1947 using about 25 varieties of black walnut, Persian, western and Asiatic walnuts, eight inch hardwood cuttings were used beginning in December and repeated in the spring of 1947. Nearly all the cuttings of the larger size (about 1/2") started in about a month and grew about two months. Then all died. There were balls of callus on many of them. One on Thomas was an inch in diameter. The bottom heat was held at 70 degrees F. This may have been too high, as on raising the cuttings it was found the callus had rotted. This procedure has possibilities.

Literature Cited

1. Institut fur Obstbau, Berlin. Die Walnusz veredlung. (Vegetative propagation of walnuts). Merkbl. Inst. Obstb. Berlin 5, pp. 15, 1936.

2. Lounsberry, C. C. Use of Growth Substance in Bench Grafting Walnuts and Hickories. Northern Nut Growers Association 1938 Report, p. 63.

3. Nelson, Julius. Fermentation and Germ Life. N. J. Ag. Exp. Sta. Bul. 134, 1899.

4. Witt, A. W. and Howard Spence. Vegetative Propagation of Walnuts. Ann. Rep. East Malling Res. Station 1926-27.



A Method of Budding Walnuts

H. LYNN TUTTLE, Clarkston, Wash.

It took man some thirty thousand years to learn to build a fire—conveniently. I thought it was going to take me that long to learn how to bud walnuts, but fortunately the period has been somewhat shortened.

When I first began to propagate, or try to propagate, walnuts, I naturally looked to the approved and accepted methods. For me, they did not work. Before I was through I think I tried them all. I patch-budded with variations and improvisations. I shield-budded and bark-grafted. I coated the wounds with grafting-wax, latex, cellophane, asphalt and paraffine. I trimmed off the bud shoulders to make a smoother tie and trimmed around the edges to make more contact. I wrapped with raffia, strings, rags and rubber strips and tacked with small nails. Whatever I did or however I did it results were all about the same—the sap soured. In fact over a period of years I tried every way I could think up or read about to bring the bud and the cambium layer together and make them stick. Results were surprisingly uniform—the sap soured.

But we must not dwell too long on the shots that missed. As with a refractory engine that will suddenly sputter, there came some elements of success. The point to learn was, why? Concentrating on the shield bud entirely we determined to find these whys. So we tried taking big slabs of bark along with the bud, peeling out the wood, breaking off the leaf stem entirely and waxing the scar and making an unnecessarily long cut for the bud. The bark stuck fairly well but the buds died. This was some encouragement and I knew that with enough time, reason and a little luck we would eventually hit the mark.

Now Dame Fortune had decreed that I be raised on a grain and stock ranch where the only trees we could see were in the distant mountains, or, if we rode in the canyons, cottonwoods and choke-cherries. My experience and training was with animals, and animals, especially horses, seem quite susceptible to accident. The first principle of treating almost any wound is to give it drainage, otherwise, both literally and figuratively, the "sap" soured. Thus it dawned on me that a tree-wound, even if only skin deep should have the same treatment as a flesh wound. And drainage, being desirable, should be ample.

It was quite late in the season but I went out and set a dozen Schafer walnut buds on eastern black stocks. These buds HAD DRAINAGE. The vertical cut of the T extended at least two inches below the bud. Success ensued, they grew. The following spring we budded as soon as the bark would slip and continued at intervals all summer. Results were good. Some of the steps we now use are probably not essential and perhaps not even the best, but there are two points that cannot be over-emphasized, namely, drainage and contact. The complete method is as follows: 1. Trim bud sticks to leave an inch of petiole on the bud. 2. Make the T cut with a long vertical slash that will extend at least an inch below the bottom of the bud. 3. Cut the bud long and deep and peel it from the wood by pinching the sides. Be carefull not to injure the bark just below the bud. 4. Insert the bud either flush with or below the cross-cut. 5. Wrap with large sized rubber budding strips just firmly enough to make good contact. Too tight wrappings curtail circulation. Do not cover the cut below the bud. The wound must have drainage. 6. Be sure that the center of the bud-cut is firm against the cambium layer. If it humps of bows and won't stay down insert a tooth-pick or bit of leaf stem or something along the center line to hold it down. We usually do this during the wrapping process.

We use no wax. We throw a wrap over the bud, shoulders even though it may press the petiole forward against the bud. If the center of the bud pulls out it will not grow although an adventitious bud may eventually start. Budding seems about equally successful any time that the bark slips freely. On walnuts this is all summer if not too dry.

Early-placed buds may make several feet growth before fall if sufficient moisture is available. On walnuts there are always dormant buds. We have used storage wood but now just cut it fresh. We have not tried draining patch-bud or grafts. Although we have not tried it we think cherries and other trees inclined to drown the buds might be better handled in this manner. Climate is a factor in the type of propagation advisable. One very fine grower using buds in California could propagate only by grafts when he moved to Western Oregon.

The kernel of my walnut budding experience may well be summarized in one word—drainage.

* * * * *

Questions asked Mr. Stoke after his demonstration of grafting and budding. [See his paper in 1946 Report, pp. 99-103.—Ed.]

Member: "How do you keep your scions?"

Stoke: "I prefer 'orange' cold storage for scionwood. This is just above freezing. Walnuts should be in full leaf before spring budding."

McDaniel: "What percentage of chestnuts did well with the 'plate' method of budding?"

Stoke: "I don't use it with chestnuts for spring budding, but sometimes for summer budding. It will work well on any variety of Persian walnut, heartnut and black walnut. Place buds on the north and northeast side of tree to prevent sun injury."

Question: "Do you find any difference in using buds from an eight or ten year old tree as against a younger tree?"

Stoke: "No, not so long as it is healthy. For spring budding I don't care to have any trees too vigorous. Cut tops off young trees three to five days after budding, and force the buds into growth. If you delay too long the bud will die. I wouldn't try to bud trees unless bark is slipping."

Member: "I have used parapin wax and covered it with old bread paper."

Stoke: "That may work because the wax was shaded. Southern sun may melt parapin and paraffin waxes."

Mr. Corsan: "Dentists, surgeons and wood carvers make the best grafters."

Question: "Can the scions be cut with a small plane?"

Stoke: "Anything you have to cut with a plane is too big. I never use a plane."

Question: "What do you use a splice graft for?"

Stoke: "Anything except walnut. In walnut I use a modified cleft graft, and I take care of the sap flow by placing the graft down about 1" or 1-1/4" below the cut (where the tree is cut off). Wax the scion but do not wax the cut. Let it bleed."

Question: "What is the value of cut leaf black walnut?"

Stoke: "Purely ornamental. Weschcke reports that it is very hardy with him."

Rick: "What about the Lamb walnut?"

Stoke: "We don't know whether the wood of grafted trees is curly or not. I sent Mr. Reed a limb from Lamb and he gave it to the forest laboratory and they found no evidence of curly grain."

Rick: "Shouldn't it be propagated until we are sure?"

Stoke: "We had Mr. Lamb himself talk before us at Roanoke and he told us about the parent tree. He doesn't know what makes one tree curly and another not."

Korn: "Is that uncommon?"

Stoke: "Not so very. Trees are most curly at the base and in the outer wood."

Question: "Do you always leave that stub on black walnut?"

Stoke: "Yes, but it should be removed later in the first summer."

Question: "Where do you use your splice graft."

Stoke: "On anything other than walnut, if scion and stock are the same size. Where stock is larger than scion I use the modified cleft graft up to sizes approaching one inch in the stock. For topworking larger stocks I use one of the forms of bark graft. For the large hickory stock Dr. Morris' bark slot graft is preferred. For large, thin-barked stocks the simple bark graft may be used. My original grafts of the Carr and Hobson Chinese chestnuts, made with scions received from Messrs. Carr and Hobson in the winter of 1932, are still perfect unions.

"I believe that grafted chestnuts growing in frost pockets are most likely to develop faulty unions; possibly frost injury to immature cells at the junction point may occur. Dr. Crane mentions a similar failure of unions between Persian and black walnuts on the Pacific Coast."

Dr. Crane: "What cut did you use in grafting those chestnuts?"

Stoke: "Modified cleft. In using Dr. Morris' bark slot graft I find it best to leave just a little of the cut face of the scion wedge above the top of the stock. This, with top of the stock cut sloping away from the scion, as illustrated, promotes quick healing with no 'die-back.'"

Dr. Smith: "Is that top slanting?"

Stoke: "Yes, I cut it slanting."

Dr. MacDaniels: "That is a good graft for walnuts, too."

Note: Mr. Stoke showed the group a picture of a mockernut tree in one of his fields which he had girdled to kill it. The tree lived four years and during those years the moisture had to go up through the inner wood.

The substance of Mr. Stoke's talk, together with illustrations, may be found on page 99 of the 1946 report.



Importance of Bud Selection in the Grafting of Nut Trees

G. J. KORN, Kalamazoo, Michigan

For many years the fruit growers have been improving the qualities of their fruits in several ways. The early pioneers of our country selected the best fruits from seedling trees. Chance seedlings that were found in pastures, by roadsides, or possibly in some out-of-the-way place, selected because of some special quality or group of qualities, still dominate our commercial plantings of fruits and nuts. Several of the apple varieties to be found in the market today are from these chance seedlings.

In more recent years some of our agricultural colleges have been breeding fruits. Such breeding has given us several of our more promising named varieties. In this way a great improvement has been brought about in our fruits.

Environment too appears to have played an important part in making changes in fruits and nuts. Nuts that are extremely hardy in the more northern latitudes, appear to have developed this hardiness gradually throughout many generations. Because of this quality we are now able to select varieties that are most likely to succeed in any particular locality.

More rapid and satisfactory methods of improving our fruits and nuts have been brought about through breeding. This development of the science of plant breeding has made it possible to blend the good qualities of two seedlings into a new variety. Man does not have to follow nature's slow hit-and-miss method of developing more desirable qualities in her products. Controlled breeding, as brought about by man, produces faster and more satisfactory results. Man's improvement over nature has come about through his choice of the qualities to be blended, and his ability to bring together two parents from widely separated parts of the earth, if necessary.

Besides breeding, we are able also to use some of the mutations or bud sports to improve our nuts as well as fruits. Although our progress in improving nuts may not yet be as spectacular as cross-breeding with apples, bud selection has already modified the list of our commercial varieties.

One of the first requisites in bud selection is so thorough a knowledge of the variety that any departure from the type will be detected. Then it will be necessary to start propagation to determine whether the variation was caused by some environmental factor, or is really a sport which can be perpetuated by vegetative propagation. You may wonder if many of our nut growers know nut varieties well enough to detect any but the most obvious sports. Nut improvement through bud selection within the variety lies ahead of us.

Among fruit growers the search seems to have been for fruits of different or more pleasing color. As nut growers we are more likely to be interested in nut sports having better size, kernel, cracking qualities, etc. Trees that are able to ripen their nuts in short or cool seasons are especially desirable in some of our more northern states.

My attention was especially called to the importance of bud selection several years ago while buying my winter's supply of apples. I was examining the splendid crop of Jonathan apples in a neighbor's large commercial orchard. On most of the Jonathan trees the apples were large and well colored and the crop was heavy. However, a few trees bore apples of inferior size and color. Upon questioning the fruit grower as to the difference in the performance of the two types of Jonathan apple trees, he explained that the better apples came from trees supplied by a nurseryman who was very particular in selecting a good bud strain. The other trees were just the ordinary strain of Jonathan.

It was while working in a commercial orchard of the grafted varieties of black walnuts that I noticed one especially promising Thomas tree. During the few years that I have observed this tree, its nuts have been of splendid size and very uniform. The kernels from the nuts from this tree were somewhat better than those from most of the other trees. I now have some grafts growing from this promising tree.

There appears to be much promise for nut improvement by cross-breeding to regroup desired qualities. Although many of us enjoy the nut contests that are conducted from time to time, it appears that our nut improvement program might move along faster if more attention were given to nut breeding and searching out desirable bud sports.

Discussion after G. J. Korn's paper.

Corsan: "Farmers should be encouraged to plant nut trees along boundary lines. Enormous amounts of fertilizer there."

J. R. Smith: "One tree in ten thousand seedlings is worth while."

Dr. Lounsberry: "We have two trees planted close together—one bears small nuts and the other large nuts. They are from the same grafting. It would seem that the trouble is in the stock. The stock makes a vast difference."



The Hemming Chinese Chestnuts

E. SAM HEMMING, Easton, Maryland

The bearing record of our row of 18 Chinese chestnuts has attracted so much attention that I thought the Association would be interested in seeing some slides of these trees, also of our experimental orchard, as well as the large quantity of small trees we grow in our nursery and the manner in which we raise them.

You will see a number of slides of chestnut trees and hear a lot about the bearing qualities, but you won't see a single nut, for unfortunately all these slides were taken between December 1946 and July 1947. You will just have to let the numerous little trees attest to the fact that these trees bear. We have 50,000 trees in our nursery.

These trees are now nineteen years old and have borne rather remarkably since 1937. They are spaced too close—an accident—but I believe that helps thorough pollination. They are now 12 and more inches in diameter, some are 30' high and the spread is at least 35' where they have the room. All but No. 14 are spreading in character; spreading character and good bearing seemed to be connected.

The bearing record of these trees has been given before but I will summarize them by years again: 1937—118 pounds; 1938 (no records); 1939-463 pounds; 1940—250 pounds; 1941—564 pounds; 1942—658 pounds; 1943—749 pounds; 1944—678 pounds; 1945—250 pounds; 1946—1,100 pounds; this year's crop will probably run 700 to 800 pounds.

The trees seem to bear much the same, with No. 14 the poorest and No. 19 the best and, like many other tree crops, they tend to alternate good and poor crops on each tree. The nuts are of good size, averaging 40 to 50 per pound (green) with No. 6 and No. 19 bearing the smallest nuts. They ripen in September with the exception of No. 19 which is a month later. Mr. Reed likes No. 16 which has a wrinkled shell. All the nuts are medium sweet to sweet and all of them fall free of the bur. I think the most significant thing is that at least 12 of the trees have nut characteristics so near alike that they are about indistinguishable, which certainly makes them a good source of seed.

The similarity of the nuts brings up the controversial subject of the seedling raised tree, and I will make some remarks in defense of this method.

1. All our parent trees are good bearers.

2. There is no extraneous pollen in the vicinity.

3. I will present as a question: Has the Chinese chestnut, like the rose and the apple been hybridized out of all semblance of the wild form?

4. The seedling tree should bring chestnuts to the average householder's table 30 years sooner than grafting will.

5. We now produce a 3'-4' tree for a very reasonable figure.

6. All varietal forms at present are as yet unstabilized (most varieties of 10 years ago have been discarded). There will probably be some duds in seedling trees, but we've had no local complaints and I wonder if they will exceed the "troubles" found in the grafted tree. We have had customers brag about what their 2 or 3 or 6 trees bore.

To prove our faith in this method we planted a test orchard. When the trees were 3 years old from 2 year transplants they bore 25 pounds. Next year, 1944, they bore 800 pounds or an average of 1 pound per tree. Right then and there we thought that we would have a real story to tell, but we had misfortune in another direction. Three years in a row we have had frosts when 6 inches of new growth were on these trees (the orchard is not as well situated as the parent trees in this respect). So we had no crops worth mentioning but neither did we have strawberries or similar fruits. This year the orchard was frosted 2/3 the way to the top so we will get quite a few nuts, maybe 500 pounds. Incidentally, we have been here 25 years and we've not had frosts like these before.

We use all of our good nuts for seed purposes, grading out all small or damaged nuts. In raising these trees, even from seed, we've had our troubles. We let them cure several weeks then plant them in well fed soil in a narrow trench about 2 inches deep. We place the nuts 5 or 6 inches apart; we fill the trench with sawdust level with the surface. We mound the soil over this about 4 inches until spring. Then it is removed. This method lets the shoots through, otherwise they tend to send 3 or 4 stems. The nut sends down the root very early in the spring. We have some trouble with the mole-mice combination; for this reason heavy soil and sawdust is better than sandy soil. As you know neither the nut nor the tree likes wet soil.

In raising the young tree the principal difficulty is in getting a trunked upright tree. A seedling, especially when transplanted the first year, flops all over like a flowering shrub. To get them up we plant them fairly close, prune them, and feed them. Our 1 year trees are usually two feet high and 2 year trees are 4 to 5 feet high. We wholesale our trees mostly to mail order nurseries and the largest had a 5% request for replacements.

There are troubles in growing Chinese chestnuts just as there are in most fruits and nut crops and, in a way, I am glad there are because I am of the opinion there is no such thing as harvesting without cultivation. For instance, if you plant them and let nature take its course—it will. It will on an apple, too.

We have found a few small lesions of chestnut blight which were removed by pruning and then painted with pine tar. They usually occurred at a previous point of pruning. Some of the transplanted seedlings have developed a twig canker at a bud, but I've never seen them kill one and even when we don't prune it out, the tree overcomes it by new growth.

The Japanese beetle attacks the chestnut but, although they were bad this year, one spraying of DDT was effective. The weevil (curculio) was bad enough last year so we are spraying this year. Small growers should put the nuts in metal containers and thus destroy the larvae, if any.

I would like to remark here that we are a nursery growing many ornamentals, and the Chinese chestnut, although low branched, is a very ornamental tree. I know of no tree that has a handsomer dark, shiny green leaf or one whose green color holds so well until frost.

Now I think you will agree I have reported the behavior of our trees fairly, the difficulties of raising the trees, and have emphasized that I doubt if you will get success with the Chinese chestnut without effort; yet in conclusion I would like to step into "fantasy". Our No. 19 tree bore 124 pounds; suppose you had 50 trees per acre bearing that quantity. You would get 6,000 pounds per acre. The European chestnut, which is not as good, brought 30c on the Baltimore market last year. That would mean $1,800.00 per acre. Imagine having 10 acres!

1947 CROP

Pounds of Chestnuts from Original Trees at Eastern Shore Nurseries, Inc.

No. 1, 78; No. 2, 58; No. 3, 51-1/4; No. 4, 7-1/2; No. 5, 49; No. 6, 31; No. 7, 34; No. 8, 31-1/2; No. 9, 63; No. 10, 40-1/2; No. 11, 61-1/2; No. 12, 64-1/2; No. 13, 56; No. 14, 47-1/2; No. 15, 74; No. 16, 60; No. 18, 106; No. 19, 25-1/2—Total, 938-3/4 pounds.

Young Orchard: 225-1/2 pounds.

Discussion after E. Sam Hemming's paper

Corsan: "Do you recommend the use of lime?"

Hemming: "We do not use lime. We use Vigoro at the rate of 1 to 1-1/2 lbs. to inch of diameter per tree."

Corsan: "Why do you use Vigoro?"

Hemming: "No particular reason, just that it is available."

Member: "What time of year do you fertilize your trees?"

Hemming: "We fertilize during the winter—usually during December."

Crane: "Last year we used a method of storing Chinese chestnuts which proved very satisfactory. Two thousand pounds of nuts were stored last year. Fall planting is good where one can use it but in a lot of areas it can not be used because of rats robbing the plantings. We have to store the nuts. The procedure we follow is to harvest every other day. Nuts are placed in tin cans with friction top lids. The lids should have one to three holes of 1/16" diameter in them to provide air. Cans are placed in storage at a temperature of 32 to 40 degrees F."

Stoke: "I keep chestnuts in the cellar in a can with an open top in what we call limestone sand. Keep wonderfully well. Chestnuts must have air."

Gravatt: "Down south we have a lot of trouble with decay. We take nuts right from the bur and put them in the soil. They give much better germination."

Crane: "The Chinese harvest their chestnuts just as soon as the bur cracks. They do not wait for the nuts to drop from the trees but harvest the nuts from the trees and store in covered pottery jars. They plant in the fall of the year. They do not hold nuts for any length of time."

Corsan: "How about charcoal?"

G. Smith: "Charcoal is good to store nuts in. They are shipped from China that way."

Smith: "Would chestnuts stand carbon bisulphide for getting the weevil out, or is the hot water treatment better?"

Crane: "Carbon bisulphide treatment is dangerous, it will kill weevils but it will also kill the nuts so they will not germinate. Unless precautions are used it may cause an explosion and fire. Methyl bromide treatment is better."

Stoke: "The hot water treatment is the best. It consists of immersing the nuts in water at 120 degrees F. for forty minutes."

Hemming: "I have raised about 100,000 seedlings and have never seen blight on any of my seedlings."

Dr. Smith: "A tree needs usually to be as big as the small end of a baseball bat before the bark opens enough to let in the blight spores."

Stoke: "Blight begins where there is rough bark which provides lodgment for the spores. Rough bark and moisture result in blight, hence the disease usually starts near the ground."

Crane: "The blight problem in the growing of chestnuts has often been stressed. I think you will have more loss from sunscald and root rot than you will from blight. Blight is a minor trouble with us. The Chinese chestnut naturally grows with a low head. It is a mistake to cut off the low branches on the trees until they attain some size, they can then be cut off."

Stoke: "Regarding the protection of nut trees against winter sun scald, I find that if you take ordinary aluminum paint and paint the south and southwest side of nut trees it will last for two years."

Dr. Smith: "Chestnut trees have blighted for me where the water table was too high and trees of same origin or better drained ground nearby did not blight. Blight is often a sign that the tree wants something it lacks—much like disease in humans."



Results of a Chinese Chestnut Rootstock Experiment

J. W. McKAY[4]

Introduction

The propagation of chestnut species by budding or grafting has been performed by different workers with varying degrees of success. Many have found that grafted trees could be produced and grown successfully but that graft union troubles developed in a certain percentage of the trees either soon after grafting or a few years later. The variety "Carr" is known to graft with difficulty in certain localities and to give a high percentage of poor unions both at the time of grafting and after a few years of growth. The question of relationship of scion and stock has been considered by many workers to have an important bearing on the success of grafting operations but no critical work has been done to determine this point. Some investigators hold that scions of one species may be grafted upon stock of another species without harmful effects. The results of the budding experiment with Chinese chestnut reported in this paper are the first of a series of tests designed to contribute needed information about stock-scion relationship in chestnuts.

[Footnote 4: Associate cytologist, Division of Fruit and Vegetable Crops and Diseases, Bureau of Plant Industry, Soils, and Agricultural Engineering, Agricultural Research Administration, U. S. Department of Agriculture.]

Description and Results

The five seedling Chinese chestnut trees used in the experiment were selected because of their heavy-bearing tendency and because of the excellent keeping quality of the nuts. Two of the trees bear nuts of large size while the other three bear nuts of medium to small size. Seeds from the five trees were planted before the use of the seedlings as stocks in the budding experiment was planned, and since the seedlings from each tree were planted together replication of the experiment was not possible. However, the stock was grown in thoroughly mixed soil in a coldframe and differences in performance of seedlings could hardly be attributed to soil heterogeneity.

Buds from the five parent trees were placed on the five lots of their own seedlings in all combinations of budwood and stock. The work was done during the first week of September when the bark of both budwood and stock was slipping yet growth had slowed down to some extent. Buds were placed about two inches below soil level on the one-year-old seedlings and the soil pulled back to cover the buds. Budding was done by means of the familiar shield or T-bud method and rubber budding strips were used as a wrap. Budwood was shipped from Albany, Ga., to Beltsville, Md., and was damaged somewhat by high temperature in transit, a factor which may be partially responsible for the overall low percentage of buds that grew.

In referring to the results presented in table I, it will be noted that considerable variation occurred in the performance of the five lots of seedlings as stock, as well as in the take of buds from the five parent trees. The totals in the last column on the right are all equivalent to percentage since 100 buds were placed on each lot of seedlings. In like manner, the totals in the bottom line are all equivalent to percentages since 100 buds of each parent tree were used.

Seedlings of stock D were decidedly inferior to seedlings of stock C in take of buds, and both of these lots of seedlings originated from large nuts. Also, scion e gave a significantly lower take of buds on all lots of seedlings than scions c or d. The scion e tree produces small nuts whereas the scion c and d trees produce large nuts. Scions a and b are intermediate in take of buds, and the source trees both produce small nuts.

Discussion

At least one significant interpretation may be made from the results of this experiment, that may partially explain the difficulties encountered heretofore in propagating chestnuts. Using the take of buds as a criterion it can be stated that in this experiment the five lots of seedlings from known parents differed in their performance as stocks. Moreover, the five parent trees used as a source of budwood differed among themselves in the capacity of their buds to grow when placed on comparable lots of stocks. If these results are correctly interpreted it is clear that both the stock and the scion may influence the success or failure of propagation technique. Doubtless both of these variables have operated together in the propagation of existing varieties and, as would be expected, the results have been unpredictable. It seems likely that the grafting and budding of chestnut varieties should be worked out in the future on the basis of using understocks derived from the seed of special trees or clones found to be suitable sources by tests for grafting performance.

It should be pointed out that the five trees used in this work originated from two lots of seed imported from neighboring localities in China and probably are closely related. The fact that significant differences were obtained in this material furnishes basis for the belief that great variability in the budding performance of the Chinese chestnut is to be encountered in the many introductions that have been made into this country.

Table I. Results of budding each of five Chinese chestnut clones on its own seedlings and on the seedlings of four other clones. The figure for each combination represents the number of buds that grew out of 20 buds placed.

SCION

a b c d e Totals S A 4 6 4 5 0 19 T B 3 2 8 4 0 17 O C 0 3 8 9 5 25 C D 1 2 3 1 1 8 K E 2 2 7 9 2 22 TOTALS 10 15 30 28 8 91

Discussion After Dr. McKay's Paper

Dr. MacDaniels: "A good scion on chestnut is one problem which we have not solved."

Dr. Smith: "I find both Carr and Hobson difficult to graft and have discontinued them."

Dr. Crane: "In California and Oregon they are having quite a lot of difficulty with graft union failure with Persian walnuts. They have used the Northern California black or Hinds walnut as root stocks. Now they find that in some cases the union fails and results in what is known as the black line disease. At the present time this trouble is the most important cause of the loss of their trees."

Dr. Smith: "Zimmerman is a good bearing variety with a good nut. I find that soil makes some difference with this variety."



Breeding Chestnut Trees: Report for 1946 and 1947

ARTHUR HARMOUNT GRAVES[5]

The chief aim of this breeding work is the development of a chestnut tree of timber type to replace the now practically defunct American species, Castanea dentata. For the principal economic value of the chestnut was not in its edible nuts but its valuable timber, the loss of which means at present many millions of dollars subtracted from the assets of the American people; and when we consider the loss for all time in the future the figures become astronomical.

[Footnote 5: Consulting Pathologist, Conn. Agric. Expt. Station; Special Agent, Conn. Geological and Natural History Survey; and Collaborator, Division of Forest Pathology, U. S. Dept. Agriculture.]

The Chestnut Blight in Italy. Early in 1946 we received a visit from Captain John B. Woodruff, of Wilton, Connecticut, who told us that while serving as Chairman of the Department of Agriculture and Forestry, and Instructor in Forestry at the Army University Study Center in Florence, Italy, he visited chestnut stands infected with the blight. Endothia parasitica was first discovered by Professor Guido Paoli in 1938 on a private estate in Busalla, about twenty miles north of the seaport city of Genoa. Since then the blight has been detected throughout the province of Genoa in the legion of Liguria; and other widely separated infections have been found. The fungus has been cultured and identified by Professor Biraghi of the Royal Pathological Station in Rome, as Endothia parasitica. It is believed to have been present in this region for from five to eight years previous to its discovery. The manner of its introduction into Italy is not known, but since Japan and the U. S. have carried on considerable commerce with Italy, either or both countries are possible sources.

The disease is spreading in Italy at a rapid rate. "By 1942 one half of the 190,000 acres of chestnut in the province of Genoa had been infected and spot infections had been discovered in the adjoining coastal province of La Spezia, also in the region of Liguria."

I am devoting some space to this situation because it means so much to the Italian people. In Italy fifteen percent of the forest is composed of chestnut. Not only does the country use the nuts as a source of food and income, approximately sixty million pounds being exported annually in former years, but the young coppice shoots are used for the weaving of baskets, older ones for poles for vineyards, still older for staves of wine casks, and the oldest for telephone and telegraph poles. "Before the war, chestnut flour was the principal food in many localities, but during the war a serious food shortage forced the people in many other areas to rely solely upon chestnut flour for weeks at a time."

Professor Aldo Pavari, Director of the Stazione Sperimentale di Selvicoltura at Florence, visited this country in the summer and fall of 1946, under the sponsorship of the UNRRA, and spent four days with me at our plantations, learning our methods and getting acquainted with the blight resistant hybrids we have been developing by the breeding together of oriental and native chestnuts. Prof. Pavari visited also the plantation of the Division of Forest Pathology at Beltsville and elsewhere, and other plantations in the west. In December we shipped to Florence, Italy, nuts of our best hybrids, and in March, scions for grafting—also this summer (1947) pollen of some of our best trees. On October 15 of this year (1947) we sent another shipment of nuts. Thus we may be able to give Italy the advantage of the progress we have made to date.

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.



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.



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.

On days of moderate temperature I wet these bags thoroughly with water once a day but on very hot or windy days I often wet them twice. This keeps the nuts moist most of the time and lowers the temperature considerably from the evaporation. In this way I can keep the nuts days and days and even weeks with very little change except a slight drying. If any spoiled nuts were missed by the water these too will show up in about 10 days with specks of white mold and can be eliminated. The other nuts seem to be as good as the day they were gathered. I only use this to keep them temperarily (as it is some trouble to wet them) and mostly for the eating nuts until I can take them to market or put them on cold storage (30 deg. to 35 deg.F.) If I attempt to hold seed nuts about a week or more I pack in damp sphagnum in crates and keep these under the shade tree with excellent results. This year I used green sphagnum with all its water and the nuts seemed to keep well in it. Some nuts have been in damp sphagnum for over 5 weeks now and are in excellent shape except for a few that spoiled at first (which I am quite sure were bad to begin with). If too much water is used some nuts will begin sprouting but it is surprising how much they can stand and show no tendency to sour.

I am of the opinion that the chestnuts in my section get ripe prematurely and that at a time when we often have our hottest and dryest weather. These nuts seem to need a period to continue their ripening under cool moist conditions which the wet sack treatment gives (or the damp sphagnum.) Even if this is not the case I have had splendid results with it whereas before I began using this method with lots of water I often became so discouraged that I thought I would have to abandon trying to put my chestnuts on the market. Now if I can get them gathered promptly I have little trouble holding them until I am ready to dispose of them.

I failed to tell you that the bad feature about my ML No. 2 tree which produced the 150 pounds of nuts is its early ripening period (the latter part of August and first part of September) which causes some of the nuts to be spoiled almost when they fall. A few hours of too hot sun seems to start the spoiling process. The tree has no other objectionable features except the nuts are only small to medium in size but nearly every one falls freely from the burs. [Nuts about 70 to the pound.—Ed.]



Some Results with Filbert Breeding at Geneva, N.Y.[6]

GEORGE L. SLATE New York (Geneva) Agricultural Experiment Station

This paper reports the results of attempts to improve filberts by hybridization at the Experiment Station at Geneva, N. Y. The filbert project was started at Geneva in the spring of 1925 when a collection of varieties from American sources was established. In later years additional varieties from European and other sources were added until about 120 were under test. As soon as the varieties had fruited for several years it became evident that many of them were inferior and not adapted to New York conditions. A few exhibited considerable merit and the range of characteristics in the different varieties indicated that it might be worth while to start a filbert breeding project with the object of combining the desirable characteristics of the better sorts.

[Footnote 6: Journal Paper No. 719, New York State Agricultural Experiment Station, Geneva, N. Y.]

It was decided first to cross Rush, a selected form of Corylus americana, with the best varieties of Corylus Avellana, Rush contributing the hardiness of the native hazel, possible resistance to filbert blight, and the hybrid vigor that sometimes results from the crossing of two species. The European filberts were expected to furnish large-sized nuts as well as dessert and cracking quality.

The first crosses were made in 1930 when two trees of the Rush variety growing on Dr. MacDaniels' place in Ithaca were pollinated with pollen of several varieties of Corylus Avellana that was brought from Geneva. Additional crosses were made at Ithaca in 1931 and 1933. In 1932 the pollinations were made at Geneva, using a Barcelona tree covered with a tightly woven cloth. No pollinations have been made since 1933.

In the spring of 1932, 535 seedlings were received from Willard G. Bixby, of Baldwin, Long Island, N. Y., which had resulted from crosses made by C. A. Reed of the United States Department of Agriculture, at Baldwin. Including these U.S.D.A. seedlings and those resulting from the breeding work at Geneva, 1,999 seedlings have fruited.

The nuts from these crosses were stratified in sand in a cold frame, dug up, and planted in the greenhouse in early March. After one transplanting they were moved to the nursery to grow for two years, when they were moved to the seedling orchard. The nuts from one year's crosses were planted directly in the nursery but germination was low due to drought.

The seedlings were spaced 10 x 5 feet in the orchard. This spacing was satisfactory if the trees came into bearing the fourth year, but if unfavorable weather eliminated the first or second crops the trees became too crowded to permit satisfactory fruiting. Usually, however, the trees fruited sufficiently to make it possible to evaluate them and remove the inferior trees so that the better seedlings would have enough room to remain for several additional crops.

During the first few years the orchard was clean cultivated until cover crops were sown in August. In later years the orchards were not cultivated but nitrogen fertilization was substituted. Satisfactory growth was maintained, but the grass and weeds made harvesting more difficult. No pruning was done except at planting time as the seedlings were all evaluated before pruning was needed. Suckers were removed around the young trees, but as they became older this was not done and some of the plants now have several stems.

Evaluating the Seedlings

The nuts were harvested in the fall after they had dropped, or, with the later maturing seedlings and those which tended to cling to the tree, they were harvested by picking or shaking them from the tree. As soon as practicable the nuts were husked and the crop of each tree weighed and recorded. Samples of nuts of every seedling fruiting were placed on paper plates, each population being by itself, and eight or ten nuts of each sample were cracked and left on the plate. The seedlings were then divided into three classes, those that were obviously good, those that were poor, and an intermediate class that received further attention. The poor seedlings were marked for discard and if so marked for two or three years they were pulled out.

The good seedlings were then examined more carefully and sorted into three groups, as follows:

1. Those that were outstanding in both nut and tree characters.

2. Those that were good enough to propagate for a second test, but not equal to the best.

3. Seedlings good enough to keep for further observation. These were usually good in one or more characteristics but deficient or doubtful in one important feature. If upon further testing these third group plants proved to be outstandingly productive or hardy they were given a higher rating.

In examining the nuts, emphasis was placed on size and color of the nut, the large, bright brown nuts being considered more desirable than the smaller, duller colored, pubescent nuts. The amount of space between the shell and the kernel was important. If the kernel fitted tightly it was easily broken or chipped in cracking the nut. Thickness of shell was of minor importance as only a few were thick enough to make cracking difficult.

The kernel characters were of most importance since the kernel is the reason for producing the nut. The kernel must be plump, smooth, light brown in color, and free of the superfluous pellicle, or fibrous material that is characteristic of the Barcelona kernels. Generally, seedlings with Rush as one parent had very little of this superfluous fibrous material and the best of them were much superior to Barcelona in appearance and dessert quality. Flavor received less consideration since most of the seedlings were reasonably good in that respect.

Given a good kernel, and there were many of them, it became necessary to rely upon other characteristics to eliminate the less desirable of these seedlings. It was here that the records of yields and catkin hardiness were valuable. After several years it became evident that certain seedlings were consistently high yielding while others were low yielding. Hardiness of catkin also varied greatly and rather consistently from year to year. Weather conditions influenced catkin killing greatly. Catkin hardiness is important since the pollen is necessary for nut production and must be present in abundance as its movement in the orchard is subject to the vagaries of the wind, and only a small percentage of that in the air ever comes in contact with the stigmas of the other varieties.

It is the purpose of this paper to indicate the value, insofar as it may be estimated from the available data, of the different varietal crosses in obtaining desirable filbert hybrids. Table 1 contains a list of crosses made, the number of seedlings raised, and the percentage of these which were of sufficient merit to be retained for further study. The percentage of seedlings propagated indicates even more definitely which crosses are of the greatest value in producing superior seedlings as only the outstanding seedlings were propagated for a second test. Selections included in Table 1 are there by virtue of their all-around merit.

Crosses between Rush and Littlepage and Rush and Winkler produced nothing of value. The populations were small, but other equally small populations from other crosses produced seedlings of value. The inter-crossing of selections of Corylus americana does not appear to be a promising line of attack in filbert breeding where hybrids with C. Avellana will thrive.

Rush and Barcelona were each used as seed parents in crosses with the same eight varieties. In the crosses involving Rush 1,232 seedlings were produced and of these 39, or 3.2%, were good enough to propagate. Of the 306 seedlings raised from the same varieties combined with Barcelona only 4, or 1.3% were worth propagating. None of these Barcelona seedlings are among the best. Under the conditions of the experiment it would seem that Rush is much superior to Barcelona as a parent in crosses with varieties of Corylus Avellana.

The cross between Kentish Cob and Cosford failed to produce any seedlings of outstanding merit.

In considering the productiveness and hardiness of the catkins of the seedlings resulting from the different crosses the data have been assembled in Tables 2 to 5, each table containing the summarized records for different plantings. These plantings were started at different times and the records are not directly comparable as they are for different years and varying lengths of time. In Table 1 the total number of seedlings is given, but in Table 2 to 5 only the data for the selections are used. Records for the selections are available for several years, whereas the inferior seedlings were discarded and limited data only are available. Furthermore, the filbert breeder is interested primarily in the worthwhile material that may be taken from populations of known parentage.

Assuming that we have a fairly good nut productiveness is the most important characteristic in a filbert. If the plant is productive it must of necessity be reasonably vigorous and hardy. For that reason much emphasis has been placed on productiveness in the final evaluation of the selections.

The selections in Table 2 are from the U.S.D.A. Bixby plants which were the first to fruit at Geneva. Considerable variation in productiveness is evident in the different populations. Rush x Kentish Cob and Rush x White Aveline selections were only about half as productive on the average as Rush x Barcelona, Bollwiller, Red Lambert, and Daviana. Rush x Italian Red also failed to produce high-yielding selections. In a later planting in the same orchard, as shown in Table 3, the Rush x Kentish Cob selections performed no better, the Rush x Red Lambert selections outyielding them by a substantial margin. The Barcelona x Italian Red selections were very low yielding.

In orchard 22, as shown in Table 4, where Rush and Barcelona are crossed with the same varieties, the resulting selections from the Rush crosses are about one third more productive if mean yields are considered, or one-half more productive if only highest yielding selections are considered than with the Barcelona crosses. Cosford has been outstanding in transmitting productiveness in crosses with Rush, Italian Red, and Nottingham. Rush x Kentish Cob selections in this orchard as in the other planting, were only about one half as productive on the average. In the crosses with Barcelona the combination with Medium Long, Red Lambert, and Italian Red were considerably more productive than crosses with Purple Aveline, Halle, Daviana, and Bollwiller.

The Kentish Cob x Cosford cross was less productive than most of the other combinations made. Kentish Cob definitely appears to transmit unproductiveness when crossed with Rush, Barcelona, and Cosford.

In orchard 8 as shown in Table 5, the trees soon became very crowded as the discards were not removed and the yield records were less reliable than in the other plantings.

Winterkilling of catkins were recorded on the selections for several years. In early April the percentage of winter-killed catkins was recorded by estimate. Tables 2 to 5 contain the mean of these estimates and a considerable variation in catkin hardiness in the different populations is evident. Red Lambert, which had the hardiest catkins of any variety of C. Avellana tried at Geneva, produced a higher proportion of catkin-hardy seedlings than any other variety. Cosford was fairly good in this respect and in orchard 16 Bollwiller, Italian Red, and Barcelona when crossed with Rush produced selections with moderately hardy catkins.

Winter injury of catkins was nearly always very high in crosses between varieties of Corylus Avellana.

Of the 1,970 seedlings included in Table 1, 340 or 17%, were retained for further observation and of these, 52, or 2.6%, were considered good enough to propagate for a more extensive test. Of these 52 a few thus far have been outstanding when compared with the others. Possibly the best and most productive selection is No. 1265, Rush x Purple Aveline, that is the heaviest yielding of all and the nuts are also among the best, being of medium size, plump, and free from fiber. This seedling is far superior to any others from the same cross. Nos. 1408 and 1467, both selected from a Rush x Cosford population, are close seconds to No. 1265. In the Rush x Cosford population are several others nearly as good, the general level of merit in this combination being fairly high. Farther down the list, but still among the best, are No. 110 Rush x Kentish Cob, and No. 157, Rush x Barcelona. Filbert breeders working under similar conditions would probably find it worthwhile to make these crosses and also to produce more seedlings from Rush x Red Lambert than were raised at Geneva.

No crosses have been made at Geneva in recent years, but all of the nuts from the selections, sometimes several hundred pounds a year, have been planted by the Soil Conservation Service and the resulting seedlings planted in various parts of the country. Undoubtedly, if these could be examined when in fruit, some worthwhile selections could be made. Those in New York State will probably be worked over during the next few years.

TABLE 1. Results from filbert crosses.

Number of Num- Percent- Number Percent- Seedlings ber Re- age Re- Prop- age Prop- Cross Fruited tained tained agated agated

Rush x Kentish Cob (Du Chilly 430 63 14 11 2 Rush x Cosford 447 52 12 11 2 Rush x Bollwiller 165 18 11 6 3 Rush x Italian Red 118 17 16 2 1 Rush x Red Lambert 36 10 28 6 16 Rush x Daviana 13 2 15 2 15 Rush x Purple Aveline 12 3 25 1 8 Rush x White Lambert 11 0 0 0 0 Rush x Barcelona 119 20 16 3 2 Rush x White Aveline 54 10 18 3 5 Rush x Imperial deTrebizond 24 5 21 1 4 Rush x Nottingham 23 7 30 2 8 Rush x Brixnut 8 2 25 0 0 Rush x Littlepage 12 0 0 0 0 Rush x Winkler 6 0 0 0 0 Barcelona x Kentish Cob (Du- Chilly) 42 21 50 3 7 Barcelona x Cosford 57 27 48 1 2 Barcelona x Bollwiller 11 2 18 0 0 Barcelona x Italian Red 66 9 13 0 0 Barcelona x Red Lambert 41 12 29 0 0 Barcelona x Daviana 21 5 24 0 0 Barcelona x Purple Aveline 25 8 32 0 0 Barcelona x White Lambert 43 1 2 0 0 Barcelona x Medium Long 45 16 35 0 0 Barcelona x Early Globe 78 0 0 0 0 Barcelona x Halle 12 6 50 0 0 Barcelona x Red Aveline 9 1 11 0 0 Kentish Cob (Du Chilly) x Cosford 35 22 63 0 0

Total 1970 340 17 52 2.6

TABLE 2. Yields and winterkilling of filbert catkins, Orchard 16, 1935 1937, 1938 and 1939. Yields are 4 year total. Catkin injury is 5 year mean

No. of Mean Highest Mean Lowest Selec- Yield Yield Percent- Percent- tions per Se- per Se- age Cat- age of lection lection kins Catkins in in Winter- Winter- Cross Ounces Ounces killed killed per Se- lection

Rush x Bollwiller 18 81 143 21 4 Bush x Kentish Cob (Du Chilly) 12 38 117 36 3 Rush x White Aveline 9 44 73 42 0 Rush x Barcelona 6 94 147 26 8 Rush x Imperial de Trebizond 5 81 100 28 10 Rush x Italian Red 3 79 80 15 3 Rush x Red Lambert 3 88 116 7 3 Rush x Daviana 2 82 110 33 26 Rush x Purple Maxima 1 37 37 17 17

TABLE 3. Yields and winter injury of filbert catkins, Orchard 16, 1937-41 inclusive.

Mean Highest Mean Lowest Yield Yield Percent- Percent- per Se- per Se- age Cat- age of No. of lection lection kins Catkins Selec- in in Winter- Winter- Cross tions Ounces Ounces killed killed per Se- lection

Rush x Kentish Cob (Du Chilly) 26 38 102 68 5 Rush x Barcelona 14 52 89 90 38 Rush x Red Lambert 5 67 117 12 5 Barcelona x Italian Red 3 18 20 83 73

TABLE 4. Filbert selections. Orchard 22. Yields 1939, 1940, 1941, 1942, 1944, 1945 and 1946. Catkin injury records 1939-42, inclusive.

Mean Highest Mean Lowest Yield Yield Percent- Percent- per Se- per Se- age Cat- age of No. of lection lection kins Catkins Selec- in in Winter- Winter- Cross tions Ounces Ounces killed killed per Se- lection

Rush x Cosford 26 129 229 42 0 Rush x Kentish Cob (Du Chilly) 25 68 185 70 13 Rush x Nottingham 7 96 180 31 14 Rush x Italian Red 3 114 181 45 30 Rush x Purple Aveline 3 114 240 42 25 Rush x Red Lambert 2 90 127 21 8 Rush x Brixnut 2 49 51 62 58 Barcelona x Cosford 27 90 138 62 32 Barcelona x Kentish Cob (Du Chilly) 21 69 126 69 25 Barcelona x Medium Long 16 93 257 83 71 Barcelona x Red Lambert 12 83 147 52 13 Barcelona x Purple Aveline 8 50 73 78 55 Barcelona x Italian Red 6 84 133 90 81 Barcelona x Halle 6 52 79 52 23 Barcelona x Daviana 5 53 75 67 59 Barcelona x Bollwiller 2 66 94 62 58 Barcelona x Red Aveline 1 91 91 56 56 Barcelona x White Lambert 1 103 103 5 5 Kentish Cob (Du Chilly) x Cosford 22 62 151 64 33

TABLE 5. Filbert selections. Orchard 8. Yields 1940, 1941, 1942 and 1944. Catkin injury records 1940, 1941 and 1942.

Mean Highest Mean Lowest Yield Yield Percent- Percent- per Se- per Se- age Cat- age of No. of lection lection kins Catkins Selec- in in Winter- Winter- Cross tions Ounces Ounces killed killed per Se- lection

Rush x Cosford 26 25 47 30 2 Rush x Italian Red 11 25 39 27 0

* * * * *

Discussion after Mr. Slate's paper—

MacDaniels: "Of the 1999 seedlings tested at Geneva, 52 are being carried on for further observations. Prof. Slate is doing a fine work."

J. R. Smith: "I want to express my appreciation of the work Prof. Slate is doing. To care for 1999 seedlings and keep the performance records is a big job and just the kind of thing on which progress depends."



Nut News from Wisconsin

CARL WESCHCKE

This year at River Falls, Wisconsin, which is only 35 miles southeast of St. Paul, Minnesota, the season started off with much rain and a delayed cold spring. All the grafting had to be postponed from two to four weeks later than normal. The stored scion wood suffered some because of this long storage period, and some of it was quite dry when taken out. This was particularly true of the Weschcke butternut and these scions looked so dry that I was tempted to throw them all away, but instead I gave them to two young horticulture students to practice with. None of them grew, however, so we had a 100% failure on butternut grafting. About a dozen years ago I had much success grafting butternut on black walnuts and was unimpressed, therefore I did not make any notes as to the process I used. This was a mistake for apparently I have lost the art. The last five years has probably produced only about five or six plants successfully grafted on black walnut. Hickories respond much better and I usually get about 50% successful grafts on my native butternut stocks.

Although the insect pests, such as the butternut curculio, were delayed in their attacks, they eventually caught up and destroyed most of the big butternut crop and did their usual damage to heartnut and Persian walnut growth. I noticed in the American Fruit Grower that plum curculio was controlled in the peach orchards through the use of hexaethyl tetraphosphate. If this chemical poison controls plum curculio, it ought to control any of the curculio family, such as the hazel curculio, chestnut curculio and butternut curculio. The butternut and hazel curculio appear to me to be the same insect. I am not troubled with the chestnut curculio yet, but if this chemical gives control over the curculio insect family we will certainly be able to raise large crops of all of the nuts mentioned.

Quite a few of my grafted test trees, both in the forest and in the orchard, which in some cases were grafted on bitternut hickory stocks fifteen years ago, are beginning to bear. These varieties are the Woods, Fox, Taylor, Platman and Davis. Others which have borne a few times previously also have good crops set. These are Bridgewater, Glover, Beaver, Kirtland, Deveaux and Fairbanks. The trees setting the largest crops of hickory nuts are the Weschcke, and they are the only ones that I can really count on maturing early enough to escape our usual early fall frosts.

I derive great pleasure in observing new seedling plants of filberts, hazels and their hybrids coming into bearing for the first time this year. There are about two hundred of these new varieties. Of course most of them will be worthless commercially. The ideal hybrid hazilbert has not yet appeared, but when it does we will propagate it for sale as rapidly as possible.

At this date, August 20, we have suffered from an extremely dry August and will apparently lose many trees that we cannot reach by irrigation or some other means of watering.

We have been busy at the farm and nursery erecting a small pilot plant for grinding filbert butter which we expect to be able to put on the market between October 15 and November 1.

There is about a one-fourth crop of black walnuts in my orchard trees, with the Thomas leading. Many of the Ohio trees are barren. Usually the Ohio bears freely.

It is my observation here that the wild hazels and some of their hybrids will drop their crop of nuts when it becomes too dry. This probably is an excellent feature from the standpoint of the plant as it no doubt saves the plant from being killed by drouth.

There is no doubt in my mind but that the hazel-filbert hybrids (hazilberts) will make a large agricultural crop in the corn belt. When these crops are shelled in local plants and ground into butter the industry will fall into much the same category as country creameries. However, we have not reached the point where we have the right commercial plants for this purpose and for the time being will have to use the Pacific Coast filberts until such large crops of the ideal hybrids appear.



Home Preparation of Filbert Butter and Other Products

MRS. JEANNE M. ALTMAN, Bellingham, Washington

Filberts may be prepared in different ways at home to make a delicious food. To make filbert butter first shell a roasting pan two-thirds full of kernels and put it in a 325 deg. oven. Stir the kernels thoroughly and often to get an even tan. Cut a few in half to determine when they are brown enough. Cook about thirty minutes. Do not leave in oven any longer than necessary because the kernels begin to brown rapidly upon further cooking. Cool and stir when not too hot. Most of the brown pellicle can be removed by rubbing kernels between one's hands. Run the kernels through a food chopper or meat grinder to make a Crunchy butter. To make a more delicious product, however, first run the kernels through a coarse knife, salt them and then run through a fine knife. This results in a butter with enough oil of its own to make a delicious dish. It takes lots of nuts to make much filbert butter.

In preparing salted filberts in quantity I cook them in a strainer in a kettle of deep fat. Check the temperature with a thermometer and do not let them get too hot. Cool them quickly by putting them into a cold dish and stirring. When salting the whole kernels put only enough fat with them to coat the pellicle. After they are sufficiently brown take them out and salt them as they are cooling. Stir just enough to coat the kernels with salt. Eat pellicle and all; it holds the salt. Stirring too much tends to remove the salt.

You can treat a pound of nuts at a time in a heavy iron skillet on top of the stove stirring constantly. When we follow that practice we eat them salted just as they were instead of grinding them. I think they are better than salted peanuts.

I sent a recipe to one of our west coast papers and they added a note to drain them on a paper towel. That is wasteful and unnecessary. A Bellingham dentist put whole nuts into his false-teeth baking oven in the evening. I do not know what temperature was maintained but it must have been low because he left the nuts there all night and the next morning he found them all roasted and ready to eat.

Filberts, even the green ones just as they come from the tree, may be boiled and then salted and buttered. They may be used to advantage in many cooking and baking recipes.



Notes from Central New York

S. H. GRAHAM, Ithaca, N. Y.

This summer has been a difficult one for black walnuts. A late spring delayed starting and three freezes during the week beginning Sept. 22 prematurely checked development so that poor filling seems to be the rule. The Persian walnuts again demonstrated their ability to ripen their nuts in a short season.

Some of our Persian walnut trees are growing in the partial shade of larger black walnut trees. We prefer to keep these larger trees as they may be valuable stocks to be grafted to the superior varieties that one is always hoping will appear later on. This condition gives a good opportunity to observe the effect of shade. There seems to be no doubt that even light shade is detrimental in our latitude to the Persian walnut and results not only in more spindling and unsymmetrical growth but also interferes with proper ripening of the wood making it more subject to winter injury.

One difficulty with the Persian walnuts in the East is premature falling of the nuts. The female flowers on the young Persian trees that we have seen are usually more numerous than with black walnuts of the same size and age, but even hand pollinating often fails to give a good set of nuts. Last spring we took pollen from eight of our Persian trees to the pomology department of our State College of Agriculture for germinating. The best sample showed 45% viable pollen; the next best 15% and the rest from O to 5%. This had been collected and stored for several weeks according to the methods given by Dr. Cox in the annual report for 1943, page 58. It is possible that this lack of viability may be due to some soil deficiency such as insufficient lime or boron. Prof. Schuster of the Oregon station writes that they find that Persian walnuts readily accept good Persian pollen but not black walnut or butternut pollen. If the viability of the pollen falls below 50% they consider it unsatisfactory. On some of the Oregon soils an application of boron in the form of ordinary borax under the trees in the spring has greatly helped in getting a crop of nuts. This should be well worth trying in the eastern states.

The filbert crop this year is better than usual. Out of over a thousand crosses between Rush and Winkler with European and Pacific Coast varieties, in our estimation, only one has proven worthy of propagation considering size, flavor, abundance of bearing and resistance to filbert blight. Some growers think lightly of blight but our experience in fighting it through the years in cutting out cankered wood has convinced us of the futility of this means of control in infested areas. Control measures may apparently succeed for a time but when conditions of moisture, heat and air movement are just right it can spread like wildfire. Therefore, to us, resistance to this disease (Cryptosporella anomala) seems of paramount importance. The prevalence of blight has been almost universal in the scattered plantings which we have visited in central New York, usually without the owner knowing why his trees were dying. All our European and Coast varieties, as well as most of the hybrids, take blight readily but there is an occasional hybrid that is clearly resistant. Bixby is one of these.

We have always used a knapsack sprayer equipped with a mist nozzle for our trees but this is inadequate as the trees grow taller. This summer a much more satisfactory nozzle was found that may be quickly adjusted to throw a mist for low trees or a far reaching one for the taller trees. This is made by the D. B. Smith Co. of Utica, N. Y.

From time to time articles appear on insects injurious to nut trees. Frequently mentioned are the web worms and the walnut caterpillars. With us, the damage they do is as nothing compared to that caused by the curculios, the strawberry root worm beetles and the leaf hoppers. We are getting the upper hand of the curculios by the use of cryolite spray but the root-worm beetle problem is still unsolved. Until Rev. Crath wrote of leaf hopper damage (Annual Report 1938 p. 111) we had not regarded them as at all serious. Subsequent observation has convinced us that he was right and that they are often the cause of the blackening and dying of the tender young leaves of Persian walnuts and the curling up of older leaves. We were especially impressed during the Wooster, Ohio, field trip last year and, later on, in seeing how Mr. Sherman had overcome this trouble on the Mahoning Co. farm simply by adding DDT to his spray mixture.

In closing, we would like to call the attention of new members to the wealth of information that is to be found in the old Association annual reports.



Experience with the Crath Carpathian Walnuts

GILBERT L. SMITH, Wassaic, New York

In the spring of 1935 we purchased from the Wisconsin Horticultural Society two pounds of the nuts which Rev. Paul Crath had imported from Poland. We planted these nuts in the nursery row. Sixty-two seedlings resulted. We assigned a number of each of these seedlings and transplanted them when they were two years old. Here we made our first mistake. We selected what proved to be a very poor site for them, adjacent to and nearly surrounded by woodland, in which were a goodly supply of butternut curculios which we have found to be by far the worst insect enemy of the Persian walnut. It attacks the terminal growth doing some damage by feeding but principally by laying eggs in the terminals and the fleshy base of the leaf stems. From these eggs grub-like larvae hatch which bore into the terminal and the leaf bases, greatly dwarfing the terminal growth. We have found as many as six larvae in a single terminal. Of course they also like to lay their eggs in the young nuts which then drop from the tree in mid-summer.

In the spring of 1937 we started to graft from these seedlings on black walnut stocks, giving each the same number as that of the seedling from which the wood was taken. It is too bad that we did not start this work sooner as we lost a few of the seedlings, largely through the ravages of the curculio, but possibly some of them were just not rugged enough to stand our climate. We still have 49 of these varieties living, either as grafts or the original trees. To this collection we have added a few varieties, securing wood from seedlings being grown by others. We have had living grafts of some of the named Crath varieties which we suppose developed from some of the wood imported from Poland by Rev. Crath. All of these have failed with us except one, Carpathian D. Apparently they were not hardy enough for our climate.