Chapter XIV: Section X: Amendments to By-Laws (7)

Table 7. Spittle Bug Control, Eldred, 1952 Second brood, sprayed July 18

============================================================
Treatment Amounts in In 200 terminals
100 gallons July 17 July 21 July 28
------------------------------------------------------------
Lindane 6 qts. of 20% 123 24 2
BHC 10 qts. of 11.7% 98 11 0
Dieldrin 6 qts. of 18-1/2% 130 19 9
Toxaphene 8 qts. of 58% 107 16 3
Check ------ 99 98 47
------------------------------------------------------------

Due to the natural reduction in the check by July 28 most attention probably should be given to the July 21 examination. This table shows approximately 92% reduction from Lindane, 87% with BHC, 85% from Dieldrin, and 85% from Toxaphene on July 21.

At Anna trees are all very big, from 50 to 75 feet high. They are planted in rows. A regular orchard sprayer was used with 600 pounds pressure using one gun and sprayed from the top of the rig. Approximately 25 gallons was used per tree. As will be noted the dosage was much smaller than at Eldred, and for ordinary use these are probably the proper dosages. Table 8 gives the results of these tests.

Table 8. Pecan Spittle Bug Control, Anna, 1952

==================================================================
Treatment Amounts in In 200 terminals
100 gallons July 10 July 14 July 22
------------------------------------------------------------------
Lindane 1 lb. of 25% 214 1 1
BHC 2-1/2 lbs. of 10% 244 5 9
Dieldrin 1 and 1/3 pints of 18-1/2% 148 3 5
Toxaphene 1 qt. of 31% 146 22 21
Check 61 47 20
-------------------------------------------------------------------

The reduction in the check block July 14 may be due to proximity to the sprayed block which was not true in Eldred. This check was small. Table 8 shows on July 14 an approximate reduction of Lindane 99%, BHC 98%, Dieldrin 98%, and Toxaphene 85%.

From these tests in both places it appears that we have a choice of three very good materials, Lindane, Benzene hexachloride called BHC and Dieldrin, and for that reason we can ignore the less efficient material, toxaphene.

At Eldred, since first brood sprays were applied in a sizeable area records of infestation were made shortly before time to spray for the second brood to determine whether the first brood spraying would eliminate the need for second brood spraying. However, the infestation was found to be practically as great in this area as the unsprayed part of the woods. It appears that the control was not good enough to allow this. In part this was due to failure to reach the tops of the trees. Records were made in the lower parts.

5. Varietal susceptibility.

At Anna where there was a limited number of trees, the orchards were plotted on paper and location of each tree with variety indicated records were made of each tree separately, in hopes that some varietal susceptibility would be shown. There is nothing very clear in this respect except that of the varieties in the Casper orchard, Butterick, Busseron, Indiana, Posey, Stewart, Osburn, Major, Green River, the Indiana and Posey may be a little more heavily infested than the others. At Eldred for the second brood infestation, the variety of each of the 10 record trees was reported, but there were so many varieties and they did not occur often enough in the five plots to make variety infestation data reliable. However, the rather high average on the Indiana variety did seem to corroborate the findings at Anna.

There was some foliage burn in two of the record trees in the Dieldrin plot at Eldred, both being the variety Rockville. Another tree in another part of the plot was also found to be burned and also found to be the same variety, so it appears that this may be particularly susceptible to spraying especially in this concentrated form such as we used. There were no Rockville trees in any of the other plots, so we have no way of knowing whether the Lindane, BHC or Toxaphene would have done the same or not.

PRESIDENT MacDANIELS: The next paper, the last paper of the afternoon, is Control of Insects Injuring Nut Trees, by Howard Baker, U.S.D.A. Bureau of Entomology and Plant Quarantine, Beltsville, Md.

MR. BAKER: Mr. Chairman, members of the Northern Nut Growers Association: It is a great deal of pleasure to be back here speaking before a group of nut growers. Back some years ago my first assignment to a station of which I had charge was an investigation to count insects in Louisiana and Eastern Texas, so it is a pleasure to be back before a group of nut growers.

Insect Enemies of Northern Tree Nuts

HOWARD BAKER, _U.S.D.A., Agr. Res. Admin., Bureau of Entomology and Plant Quarantine_

The small number of requests for information on insect pests of northern tree nuts received in the Bureau of Entomology and Plant Quarantine is a strong indication that such pests are of little concern to northern nut growers. This is fortunate, because intensive, all-season spray programs, such as are necessary to produce most other crops without serious losses due to insect injury, are laborious and expensive and not always as effective as desired. However, as your acreage is increased and as your trees become older and larger, insect problems are likely to increase in number and intensity and require more of your thought and attention.

A somewhat similar situation prevailed in the pecan industry at one time in the South. I well remember the statement of one of the larger pecan growers in Louisiana to the effect that all the pleasure of growing pecans would be gone the day he had to start spraying to control insects and diseases. Only a short time later it became necessary for him to initiate a regular spray program. He still took great pride in growing pecans, however. It is well, therefore, for you to watch your trees closely for insect damage and keep informed concerning the habits and control of the species that show up in your plantings or in those of your neighbors.

Because of the scattered nature of the northern nut industry, the small size of most plantings, and the more pressing demands for information on the control of pests of more intensively planted crops, it has not been possible for the Bureau of Entomology and Plant Quarantine to give attention to many of the pests of northern nuts. A great deal of work has been done on the pests of pecans in the South, and some work on those that attack filberts and chestnuts. In addition, some of the pests with which you are concerned, or others similar to them, are receiving attention in connection with studies of pests of tree fruits. The results of these studies will give you up-to-date information applicable to your particular problems.

The timely use of insecticides is the most effective means of combating most injurious insects, but if spraying is not possible, other methods can often be used to prevent or reduce damage. A great many new insecticides have become available during the last six or seven years. Work with them has resulted in the development of treatments effective against a number of pests for which there was formerly no known means of control and markedly more effective treatments for the control of others. It is my purpose to bring to you as much of this new information as is applicable to your problems.

Leaf-feeding Caterpillars

The fall webworm[3] and the walnut caterpillar[4] are the leaf-feeding caterpillars most commonly reported as attacking northern tree nuts.

Fall webworms[5] are the insects usually responsible for unsightly webs on or near the end of the branches of the trees during the summer and fall. They enlarge the webs as they need more leaves. When nearly full grown they scatter to complete their feeding. The full-grown caterpillars are a little more than an inch in length and are covered with long black and white hairs. They spend the winter in cocoons in trash on the ground or just below the surface of the soil. There are two broods a year in many areas, the second usually being the more numerous.

Control can be obtained by applying a spray containing 3 pounds of lead arsenate with an equal quantity of hydrated lime (to prevent possible injury to the foliage), 2 pounds of 50-percent DDT wettable powder, or 2 pounds of 15-percent parathion wettable powder per 100 gallons of water. Apply the spray when the caterpillars are still small. Follow the precautions furnished with each package. Parathion is a particularly dangerous material to use. If you are not equipped to spray or have only a few trees, you can control this insect by removing the webs from the trees with a long-handled pruner or a long bamboo pole with a hook at the end.

The walnut caterpillar feeds in groups, or colonies, and commonly eats all the leaves on small trees or on certain limbs on large trees. The winter is spent in cocoons in the ground. The moths appear late in the spring or early in the summer and lay masses of eggs on the underside of the leaves. From time to time as they grow, the stout, black caterpillars go down to a large limb or to the trunk of the tree to molt, or shed their skins. After molting they return toward the ends of the branches and resume their feeding.

This insect can be controlled with the same spray treatments that are recommended for the fall webworm, and also by crushing or burning the caterpillars when they are clustered on the lower limbs or tree trunks.

Pecan Phylloxera[6]

Swellings called galls sometimes appear on leaves, leafstalks, succulent shoots, or nuts of the current season's growth of hickory and pecan. These galls are caused by small insects known as phylloxera, which are closely related to aphids, or plant lice. Several species are involved, but only one, known as the pecan phylloxera, causes serious damage. It causes twigs to become malformed, weakened and finally to die, and destroys the crop on the infested terminals. The insect passes the winter in the egg stage in protected places on the trees. The young appear in the spring about the time the buds begin to unfold.

The phylloxera can be controlled by spraying the trees thoroughly with a mixture containing 3/4 pint of nicotine sulfate plus 2-1/2 gallons of lime-sulfur or 2 quarts of lubricating-oil emulsion to 100 gallons of water during the delayed dormant period or by the time buds show about an inch of green. Sprays containing 3 pounds of BHC (10-percent gamma) or 1-1/4 pounds of 25-percent lindane wettable powder per 100 gallons are also effective, and their use is increasing. Other materials have given good control when applied about the time the buds begin to swell. They are 36-percent dinitro-o-sec-butylphenol liquid, 3 quarts per 100 gallons, and a mixture of 40-percent dinitro-o-cyclohexylphenol powder, 2 pounds, and lubricating-oil emulsion, 5 quarts, per 100 gallons of spray. Do not use the dinitro materials after the buds begin to open.

Twig Girdler

A stout, brown beetle about 1/2 inch in length, known as the twig girdler,[7] often cuts off the twigs of hickory, pecan, and many other trees in the late summer and early fall. The larvae spend the winter in the cut twigs, which are gradually broken off and fall to the ground. Injury can be reduced by collecting and destroying the fallen twigs before the larvae complete development the following spring. Recent work on pecans in Florida indicates that most injury can be prevented by applying a spray containing 4 pounds of 50-percent DDT or 3 pounds of 15-percent parathion wettable powder per 100 gallons of water. Three applications appear to be necessary, the first when the injured branches are first noticed, usually sometime in August, and the second and third two and four weeks later. When handling parathion be sure to follow the precautions on the package.

Weevils and Curculios

Weevils and curculios are small, hard-shelled, grayish to brown beetles about 1/4 to 1/2 inch long, with stiff, slender snouts or beaks. They feed and lay eggs in the nuts and/or shoots of many kinds of nuts, including hickory, walnut, pecan, chestnut, hazelnut or filbert, and butternut. There are a number of species, but most of them attack only one kind of nut. The species usually called weevils most often lay eggs and injure the nuts from the time the meat begins to form until it is mature, whereas the group known as curculios generally emerge and cause most serious damage during the early part of the growing season, when the new shoots are developing and the crop starts to set and grow.

The chestnut weevils are probably the weevils best known to most of you. E. R. VanLeeuwen, of the Bureau of Entomology and Plant Quarantine, has added much to our knowledge of these weevils in recent years. Two species, the small chestnut weevil[8] and the large chestnut weevil,[9] are commonly present together and cause similar injury. The small chestnut weevil appears as an adult over a period of about 6 weeks beginning near the first of May in the vicinity of Beltsville, Md., but it does not lay eggs until about the middle of August. The larger species does not emerge until about the middle of August and begins to lay eggs soon thereafter. Eggs are laid in the developing nuts, and injury is caused by the feeding of the larvae therein. Most of the small weevils require two years to complete development, and most of the larger weevils but one year.

Some control of these weevils can be obtained by collecting and destroying the infested nuts before the larvae leave them to enter the soil. Better control can be obtained by spraying the trees with DDT. Apply a spray containing 4 pounds of 50-percent DDT wettable powder per 100 gallons of water (3 level tablespoonfuls per gallon) 30 days before the first mature nuts are expected to drop, and make two additional applications at intervals of 7 days. If you are not equipped to spray, you may obtain some control by treating the soil under the trees with ethylene dibromide at a depth of 5 inches. Make injections at intervals of 1 foot in each direction and also in the center of each square formed by these injection holes. Place 1 milliliter of 40-percent ethylene dibromide or an equivalent quantity of another dilution in each hole. Make the application in the fall immediately after the nuts are harvested and close the injection holes by pressing with the foot. The soil should preferably be loose to a depth of 5 inches.

The pecan weevil,[10] also known as the hickory nut weevil, often causes heavy losses of pecans and most species of hickory. Two or three years are required for the insect to complete its life cycle, but some specimens reach maturity every year. Adults emerge from the ground from the middle of July until early in September, according to locality and seasonal conditions. Injury is of two types--(1) that resulting from attack before the shell-hardening period in July and August, causing the young nuts to drop, and (2) that resulting from attack after kernel formation, the kernel being destroyed by the developing larvae, or grubs. Egg deposition in the nuts usually begins late in August.

To control this weevil spray the trees twice with 6 pounds of 50-percent DDT or 40-percent toxaphene wettable powder per 100 gallons of water. Make the first application when at least six weevils can be jarred onto a sheet on the ground beneath any tree known to have been infested in previous seasons, and make the second 10 to 14 days later. The first application will be needed sometime between the last week in July and the first week in September. If the soil is hard and dry, it will delay emergence of the weevils. If you are not equipped to spray, you can reduce weevil injury about 50 percent by jarring the limbs of the trees lightly and gathering the weevils on a sheet during the period of emergence. The dislodged weevils will remain quiet on the sheet long enough to be picked up and destroyed. Begin jarring about the last week in July and confine it to two or three trees until the first weevils appear. Then jar all trees at weekly intervals until about the middle of September, when egg laying will have been largely completed.

The butternut curculio[11] attacks native butternuts and introduced nuts of a similar type. It passes the winter as an adult in trash or other shelter it can find in the vicinity of nut trees. It is a small, hard-shelled, rough-backed snout beetle. Late in the spring it makes its way to the trees, and lays eggs in the young shoots. On hatching, the young larva penetrates into the young shoot or leaf stem or nut and feeds there, causing the leaf or nut to dry up and fall off. Upon completing development in the fallen leaf or nut, the mature larva enters the soil. After a month or so in the ground the adult emerges, feeds on the foliage for a while, and then enters hibernation. There is but one generation a year.

The black walnut curculio[12] is similar to the butternut curculio in seasonal history, but it attacks principally the fruit of the black walnut and butternut, apparently preferring the former.

The hickory nut curculio[13] is much like the preceding two species, but it attacks chiefly partly grown hickory nuts, causing a heavy dropping in midsummer.

The hickory shoot curculio[14] attacks chiefly the shoots of various kinds of hickory. The damage is seldom of much importance except to newly transplanted trees. On pecan it attacks the unfolding buds and shoots. Pecans most commonly attacked are those that are uncultivated or are adjacent to woodlands containing native pecan and hickory trees.

For many years these curculios have been controlled by spraying the trees soon after growth starts with lead arsenate, 2 pounds per 100 gallons, plus an equal amount of hydrated lime. One or two additional applications may be needed as new growth appears or as the nuts increase in size. Recent experimental work indicates that BHC or lindane may be more effective for controlling these insects. A spray containing 3 or 4 pounds of technical BHC (10-percent gamma) or 1-1/2 to 2 pounds of 25-percent lindane wettable powder per 100 gallons, applied when the buds show from 1/4 to 1 inch of green growth or when jarrings show adults are present, has given fairly good control.

Walnut Husk Maggot

The walnut husk maggot[15] attacks black and English walnuts, butternuts, and a few other nuts. The feeding of the larva, or maggot, in the husks impairs the quality of the kernels, discolors the shell, and often causes the shells to adhere to the nuts. It causes the most damage to English walnuts. This insect hibernates in the pupal stage in the ground. In midsummer it transforms to the adult fly stage, leaves the soil, and flies to the nut trees. After 1 to 3 weeks the flies lay eggs in the husks of the developing nuts. The eggs hatch in a week or 10 days, and the young maggots burrow within and throughout the husks of the nuts; they mature in the fall.

The walnut husk maggot can be controlled by spraying the trees with lead arsenate or cryolite the latter part of July and again 3 to 4 weeks later. Use 2 or 3 pounds of lead arsenate plus an equal quantity of hydrated lime or 3 pounds of cryolite per 100 gallons of water.

Filbert Moth

The filbert moth,[16] a serious pest in some filbert orchards in Oregon, also causes some injury to chestnuts. Adult moths begin emerging toward the end of June and lay their eggs singly on the leaves beginning early in July. The newly hatched larvae tunnel through the husk and feed between the husk and the chestnut shell before entering the nut. This feeding produces a gummy substance, which causes the husk to adhere to the nut. The larvae may tunnel into the center of the kernel or excavate an irregular cavity in the side. They reach maturity about the time nuts are ripe, and then leave the nuts and construct cocoons in the soil in which to pass the winter.

Control can be obtained by spraying the tree with lead arsenate or DDT early in July. Use 3 pounds of lead arsenate or 2 pounds of 50-percent DDT wettable powder in 100 gallons of water.

Mites

Two general types of mites sometimes damage nut trees, eriophyid mites and spider mites. The most important eriophyid mites are the wormlike gall mites and bud mites, most of which overwinter in the buds and cause deformities of the buds and leaves and otherwise limit their development. The spider mites may overwinter in the egg stage on the twigs or as adults in protected places on or beneath the trees. These mites feed primarily on the foliage.

The filbert bud mite[17] is occasionally of economic importance as a pest of filberts in Oregon and has been of some concern recently in New York. It attacks the leaf and flower buds and catkins. Infested catkins become distorted, rigid, and brittle, and yield no pollen. In Oregon this pest has been controlled with 3 gallons of a dormant oil emulsion or 6-1/2 to 8 gallons of liquid lime-sulfur in water to make 100 gallons of spray just as the buds are opening. Related species of similar habits that attack walnuts have been controlled with 9 or 10 gallons of liquid lime-sulfur in water to make 100 gallons of spray applied at the time the buds break or soon thereafter.

The feeding of the spider mites on the foliage of infested trees causes it first to have a bronzed or scorched appearance, and later to dry up and fall. These mites frequently become abundant following the use of some of the new organic insecticides, such as DDT and BHC, which destroy their natural enemies and perhaps have other effects on the trees favorable to mite activity. The European red mite, which overwinters on the trees in the egg stage, can be controlled by application of 3-percent oil-emulsion spray in the late-dormant period. The two-spotted spider mite and related species, as well as the European red mite if it is not controlled with the dormant spray, can be controlled with a spray containing 1 pound of a 15-percent parathion or 1-1/2 pounds of a 15-percent Aramite wettable powder per 100 gallons. Apply the spray before many leaves show the typical bronzing or leaf scorching. If the infestation is heavy, a second application may be necessary in about 8 or 10 days. Be sure to follow the precautions on the container, especially if you use parathion.

PRESIDENT MacDANIELS: We greatly appreciate your care in getting this thing together, and we know it is going to be a great help to us when we get it printed as a matter of reference.

MR. O'ROURKE: I'd like to ask Dr. Baker if insects are getting stronger or if the chemicals are getting weaker. I refer to the rates of application. Formerly we were told that one-half pound of parathion for one hundred gallons and one pound of DDT would control almost all insects. I note the rates are going up.

MR. BAKER: That's true, particularly with parathion. The first year that we tested parathion on any scale we thought a quarter to a half a pound would control mites for 30 days or more and would control curculio for 20 or 30 days, but the next year we used it we found that was a little optimistic. It seems that each year since we have had to use more of it or use it more often, or with mites, particularly, there are a number of instances where it just doesn't control them at all.

Two years ago that came to notice in the Wenatchee area of Washington on apples. Mites in a certain orchard just couldn't be controlled with parathion. A year ago the area in the Pacific Northwest where that was true was extended and included several orchards of the Yakima Valley. This year it also includes orchards in the East, in New York. We have seen an orchard where two pounds of parathion and a hundred gallons of water just didn't have much effect on the mites, and we have had to use other materials. We hear of instances of codling moth on apples where DDT doesn't seem to be as good as it was in the beginning. I have talked with some of the people working on the problem, and they find that there is quite a difference between different brands of some of these insecticides. Possibly that is the answer.

MR. MACHOVINA: After spraying for shuck maggot with DDT do you encourage the presence of mites?

MR. BAKER: It's very possible that you might. That has happened where DDT has been used. With some of our work with chestnut weevils, mites seem to be a little more abundant where we used DDT. We have had reports of this happening in California where they used DDT on walnuts. So it is a possibility, and that's why I brought into the paper a little information on the control of mites.

Session closed at 4:15 o'clock, p.m.

FOOTNOTES:

[Footnote 3: _Hyphantria cunea_ (Drury).]

[Footnote 4: _Datana integerrima_ G. & R.]

[Footnote 5: _Clastoptera achatina_ Germ.]

[Footnote 6: _Phylloxera devastatrix_ Perg.]

[Footnote 7: _Oncideres cingulata_ (Say).]

[Footnote 8: _Curculio auriger_ Casey.]

[Footnote 9: _C. proboscideus_ F.]

[Footnote 10: _Curculio caryae_ (Horn).]

[Footnote 11: _Conotrachelus juglandis_ Lee.]

[Footnote 12: _Conotrachelus retentus_ Say.]

[Footnote 13: _Conotrachelus affinis_ Boh.]

[Footnote 14: _Conotrachelus aratus_ Germ.]

[Footnote 15: _Rhagoletis suavis_ Loew.]

[Footnote 16: _Melissopus latiferreanus_ (Wlsm.)]

[Footnote 17: _Phytoptus avellanae_ Nal.]

TUESDAY EVENING BANQUET SESSION

We will now have the report of the Resolutions Committee.

MR. DAVIDSON: "To Royal Oakes, Chairman of the Program Committee, and to J. Ford Wilkinson, the City of Rockport and its hospitable people, the Northern Nut Growers Association extends its grateful greetings to you and to your loyal helpers, mentioning only a few; that is, Mrs. Negus, Mr. and Mrs. Sly, Mr. Richard Best, a group of people who say little and who do much, our very hearty thanks to you and to your helpers. We have had a splendid meeting, good attendance, good fellowship and tomorrow a good field trip.

"RESOLUTION: The sincere and grateful appreciation of this Association is hereby tendered to J. C. McDaniel, who has so faithfully and fruitfully served it as Secretary for five years. Your creation of new avenues of service, such as _The Nutshell_ is sufficient evidence of your resourcefulness in a difficult and most important office.

"RESOLUTION: Be it resolved, that this Association instruct its Secretary to communicate the following action to the responsible agencies of Federal and State authorities in all areas where the oak wilt disease is present or threatens:

"'The oak wilt disease threatens severe damage to our eastern and southern oaks and Chinese chestnut trees. Recently reported spread of the disease in Ohio, West Virginia, Maryland and Pennsylvania indicates a very serious and critical situation. All state and federal authorities are urged to take prompt and appropriate action before it is too late.'"

All NNGA members are asked to write to their state and federal senators and representatives urging immediate preventive measures against the spread and for the eradication of the oak wilt disease. Please write those letters. They are important.

"To Dr. Deming, greetings and congratulations from your Association on the occasion of your 90th birthday, September 1, 1952. May your years continue to be golden and happy. May our organization deserve in the future the gifts of inspiration and accomplishment that you have had so large a part in giving it in the past."

"To Dr. J. Russell Smith: The Northern Nut Growers assembled at Rockport send greetings and best wishes to you. We miss you this year and hope to see you at Rochester, New York, next year."

"To Mildred Jones Langdoc. Mildred: We have missed you at our meeting. Your absence is noted by all who know you. May the illness in your home be short. May we see you and your family in Rochester in 1953."

"RESOLUTION: On behalf of the members of the Northern Nut Growers Association the Secretary is asked to send our affectionate greetings to two well-loved, absent members, Mrs. C. A. Reed and Mrs. G. A. Zimmerman: 'Best wishes to you both for speedy recovery of good health and with our hope to see you next year.'"

PRESIDENT MacDANIELS: Is it your pleasure to adopt these resolutions all at once, or do you wish to separate them? I take it that you wish to adopt them, all at the same time, and to that end a motion to accept the report of the Resolutions Committee and to adopt the resolutions and to send the greetings would be appropriate.

The report of the resolutions committee was accepted unanimously.

MR. MCDANIEL: Before this meeting convened we planned a bud wood exchange at the convention. Mr. Gerardi and I brought some buds, and Mr. Richard brought a few of the Rhodes heartnut. We have persimmons, some buds of the new Crandall apple, and a few sticks of Chinese and hybrid chestnuts. They are for anyone who would like to experiment with them.

PRESIDENT MacDANIELS: Next year at Rochester we are going to have opportunity for putting on a considerable exhibit of nuts, and I think that it would be much to the advantage of the Association, if we could have an outstanding exhibit there where there is a good chance to have a large number of people see the exhibits and become interested. To that end I think that all of us who have nut trees bearing this fall, should save some samples with extra care; that is, clean them up, make them look attractive and have them on hand ready for the exhibit next fall.

A good sample for exhibit should be about 10 or a dozen for black walnuts and the Persian walnuts and perhaps 20 to 25 for the hickories and the smaller nuts, the hazel, particularly. I think that we have a good chance next year to forward the cause of the Association, and certainly having these exhibits will be much to our advantage.

At this time, towards the end of our session, it is our usual custom to elect our next year's officers. Before going on with that election, I would just like to say that I personally, as president of the Association during this year, wish to thank all of the other officers who have worked with me. It has been a pleasure to work with them and with the committee chairmen, and I think the meeting here at Rockport and the work during the year attest to their effective service.

The Nominations Committee report. For president next year, Mr. R. B. Best; for vice-president, George Salzer of Rochester, New York; for Treasurer, Carl Prell of South Bend, Indiana, who continues in the office; and for Secretary Mr. Spencer Chase of Norris, Tennessee.

The slate presented was elected unanimously.

A nominating committee consisting of Max Hardy, Gilbert Becker, George Slate, Dr. William Rohrbacker, and Ford Wilkinson was unanimously elected for 1953.

PRESIDENT MacDANIELS: I will now call upon our newly elected president to come forward. It is usual at these meetings for the retiring president to present the gavel to the incoming president, and here it is. This gavel is made of pecan wood presented to the Association by Mr. T. P. Littlepage, who was born in this locality. I hope you will have as much fun and pleasure as president of the Association as I have had. It's all yours.

MR. WILKINSON: That gavel was made from the wood of a pecan tree. Mr. T. P. Littlepage planted the nut when he was 14 years old on a piece of land that he inherited as a boy. I cut the wood and sent it to him in Washington to have the gavel made of it.

Chestnut Breeding

Report for 1951-1952

ARTHUR H. GRAVES[18] and HANS NIENSTAEDT, _Connecticut Agricultural Experiment Station, New Haven, Conn._

Weather Conditions

Two serious enemies of the chestnut, if we disregard parasitic organisms, are drought and extreme cold. The winter of 1950-51 was unusually mild--scarcely cold enough to freeze the ground. The precipitation was plentiful during the winter months so that the water table was sufficient to tide over a slightly dry June and a much more serious drought in September and early October. But the latter dry period came when the nuts were matured, or nearly so.

The winter of 1951-52 was again mild except for a short cold spell at the end of January, with plentiful precipitation up to the first week of June, and then a long drought with the driest July since 1944. However, the heavy rainfall of August, 8.69 inches,[19] made amends for this, and with the normal rainfall of 3.48 inches of September, prepared the trees to endure the long drought of October and early November. This serious drought,[20] which resulted in disastrous forest fires filling the air with smoke over much of the New England States, came late, however, after the nuts were nearly matured, some of the early kinds being ripe as early as the first week in September.

The excessive heat of July, in which month occurred the greatest number of days on record with a maximum temperature of 90 degrees or above, was probably the chief cause of somewhat smaller results from our cross pollination work. There is evidence, indeed, that for effective fertilization, considerable heat is needed, but not the extreme temperatures that occurred during this period.

In spite of the mild winter of 1951-52, the attacks of _Cryptodiaporthe castanea_ (Tul.) Wehmeyer caused considerable twig blight, especially on our crosses of _Castanea mollissimax seguini_. This is not surprising since _C. seguini_ comes from a warmer region in China, but why these attacks should occur during a mild winter is a puzzle. Evidently other factors, such as the drought of the preceding fall, entered in.

Hybridization in 1951 and 1952

A total of 2400 hybrid nuts was harvested in the 1951 season and 1690 in 1952. This compares with the 1259 nuts reported for 1950. The increased production over past years can in part be ascribed to a concentration of the efforts on a fewer number of different crosses; while 103 were made in 1950, the total was 77 in 1951 and 80 in 1952. The pollinations followed the same general program in the two seasons, the emphasis being on the Chinese x (Japanese x American) hybrids. This is our most promising timber tree hybrid, and it seems worthwhile to test it on a somewhat larger scale under forest conditions. Therefore, some of the best early crosses have been repeated, new parent trees are being tried and selected hybrids intercrossed. Back-crosses to the native chestnut with the CxJA hybrids were made in an attempt to improve the form of the hybrid.

Another cross which has attained some importance in the last years is the hybrid between Japanese chestnut (forest type, from U.S.D.A.) and S-8, the latter being a hybrid between Japanese chestnut and _C. pumila_, the common chinquapin. This cross has a high degree of resistance and a sufficiently good form to make it a possible timber tree (Fig. 1). It is also a fairly good nut bearer with nuts which ripen early, perhaps due to the influence of the chinquapin parent (Fig. 2). Selected individuals of this hybrid were intercrossed, and some crossing with the native chestnut was done.

In the last two seasons the total harvest from some older Chinese trees (26 yrs.) was recorded. The best tree yielded 25.0 lbs. in 1951 and 28.2 lbs. in 1952; on other trees the yield varied between 15 to 22 lbs. The average size of the nuts varies considerably from year to year on the same tree. On one Japanese tree the average weight per nut was 5.6 g. in 1951 and 14.5 g. in 1952; on a Chinese tree the same values were 7.7 g. and 15.1 g. Other trees showed a 20-40 per cent increase in the average weight per nut in 1952 over 1951. This seems to indicate a marked influence of the climatic conditions during the latter part of the growing season on the weight of the nuts. A long-term study of this relationship might yield some interesting results.

Grafting

A considerable amount of grafting has been done since 1949 and the results have been good. Two year old Chinese transplants are usually used as rootstocks and all grafting is done in the field. The best results have been obtained where the rootstock plant was transplanted one year prior to the grafting. The simple splicegraft, or the bark or rind graft are used, depending on the size of the scion compared to that of the rootstock, the latter technique being used when the stock is considerably larger than the scion. There is some evidence of incompatibility; thus, scions from Chinese trees, or hybrids that show a dominance of Chinese characters, give a higher percentage of takes when grafted on Chinese rootstocks than scions from the native chestnut, or from hybrids between Japanese and native chestnut. Some indications of incompatibility between European and Chinese chestnut in grafts have also been encountered where scions received through the cooperation of Dr. C. Schad, Centre de Recherches agronomiques du Massif Central, France, and Count F. M. Knuth, Knuthenborg, Denmark, were used, but in some cases these grafts were successful. Topworking, using the veneer crown graft, has been quite successful as long as sufficient sap drawers are left on the stock (Fig. 3).

Inarching

The senior writer has already explained in detail (2) the simple method by which blighted chestnut trees can be restored to health and vigor by cutting out blighted areas in the bark, painting them over, and inarching or ingrafting one or more basal shoots into the healthy bark above the lesion. We do this work from mid-April to mid-May, and make a systematic canvas of all the trees in all our plantations, inarching all those where if is necessary or might be advantageous. Each operation requires only a few minutes. Last year we put in many hundreds of inarches, altogether, which later showed nearly 100% "take".

Owners of chestnut orchards should take advantage of this method of keeping valuable nut-bearing trees, although with cankered areas, in healthy, vigorous condition.

We believe that, in cutting out the diseased bark, it is advisable to cut out also a few of the outer annual rings of wood (of course tangentially), especially if the canker is one of long-standing, since we know that the fungus eventually penetrates the outer rings of wood. Since that is true, the canker might enlarge later on from this same source of infection. Further it may also be possible for spores or bits of mycelium to be transported upward in the sap stream and cause new infections higher up in the tree. A thorough painting of the cut surfaces should go far toward remedying this situation.

One can usually judge the extent of damage caused by the blight by the number and vitality of the basal shoots, a large number of basal shoots indicating a heavy attack. However, if the roots have been severely injured, perhaps by short-tailed mice, as sometimes happens, no basal shoots appear, in which case the tree is doomed.

If no blight is present, but one or more basal shoots appear (sometimes due to shrubby ancestors), it is advisable to inarch these as an insurance against possible trouble in the future.

This inarching process has not received the attention it deserves. There is absolutely no reason why, if this method is followed, there should be _any_ death from blight in resistant hybrids or in Japanese or Chinese chestnuts, barring, of course, cases where roots are attacked by mice (or _Phytophthora_ in warmer regions). Those of our trees in Connecticut which have been blighted have continued in health and nut-bearing ever since we began the inarching method in 1937 (Fig. 4). If the inarches become blighted, they can themselves be inarched, as shown.

Research on Blight Resistance

A study has been made of the factors that cause the Chinese and Japanese chestnut to be resistant to the Endothia canker, and a close correlation was found between the tannin content of the bark and the relative resistance of the three species, i.e., Chinese, Japanese and American chestnut. The total tannin concentration in the bark of the Asiatic species is only slightly higher than in the American, and native trees can be found with as high a concentration as is found in the Asiatic. A similar overlap in resistance does not occur and it is therefore clear that the total tannin concentration as such cannot account for resistance. There is, however, good evidence that the tannins in the Asiatic species, as a result of the way in which they are bound to other colloids in the cells, are more soluble than in the American species. This, of course, would have a marked bearing on the effectiveness with which the tannins could check the spread of the parasite. Furthermore, it has been found that the types of tannins in the three species differ. In the American and Japanese species they are a mixture of catechol and pyrogallol tannins, while they appear to be pure pyrogallol tannins in the Chinese species. Considering the specificity of the enzyme systems of fungi it is quite possible that different tannins show different degrees of toxicity to a certain fungus. The following hypothesis has been suggested to explain the relative resistance of the three species: In the American chestnut bark the concentration of the available toxic tannin never reaches a level where it can stop the advancing parasite. The tannins in the Japanese species, although of the same type as in the native tree, are more soluble and reach a level toxic to the fungus. In the Chinese trees all the tannins of the bark belong to the toxic pyrogallol groups, and this, combined with their high solubility, results in the high degree of resistance in this species (4).

The information available at present regarding the formation of tannins in plants is not conclusive. In some plants, apparently, they are formed in the leaves, and the presence of carbon dioxide and light is required; in other plants the tannin concentration can increase when the plants are grown in darkness (5). A more general formation of tannin in tissues with a high metabolic rate throughout the plant has also been suggested (3).

It would be important to know the centers of origin of the tannins in the chestnut, their translocation, and whether they are translocated through or over graft-unions. In other words, will a susceptible scion when grafted on a resistant rootstock become more resistant because antibiotic substances formed in the roots of the resistant rootstock are translocated into the scion?

From a number of older grafts of non-resistant Japanese-American hybrid scions on Japanese or Chinese rootstocks it appears that this indeed might be the case. These grafts, some of which are 16 years old, appear to be more resistant than the original hybrid tree, even if not as resistant as the rootstock.

This would indicate the possibility that the antibiotic substances are produced in the roots and translocated into the scion. However, the possibility still remains that the compounds are formed also in the leaves and translocated to the base of the tree. To clarify this whole problem an experiment with Chinese-American grafts in different combinations is under way. Preliminary results show that antibiotic substances are formed in upper parts of the plants, but that they are not translocated downward across the graft union. Thus it was found that Chinese branches grafted on two year old American seedlings remained resistant, without the American seedlings showing any increase in resistance. In future experiments the upward translocation will be studied in detail on grafts of American scions on Chinese seedlings.

Some Abnormal Conditions

1. _Sterility_

Sterility occurs quite commonly in interspecific hybrids either because the chromosomes fail to pair in meiosis or because the parent genes when brought together in the hybrid interact in some way deleterious to the formation of sex-cells. Furthermore, cytoplasmic sterility is likely to occur in a wide cross.

Sterility has been encountered in several instances in American x Chinese and Japanese x American hybrids. In most cases it is a case of pollen abortion only; either anthers fail to develop completely as shown in Fig. 5, B, or the anthers develop but are much reduced in size and contain no functioning germ cells.

Pollen sterility is not sporadic in a given individual: it is uniform throughout the flowering branches. The individual flowers are arranged on the catkin axis as in the normal flowers (Fig. 5). But when the flowers open, a hand lens reveals 3-5 tiny, membranous perianth-segments for each tiny flower, whitish in color, and more or less connected at their bases. A minute rounded mass appears in the center of the flower, perhaps primordia of abortive stamens, but this does not develop further. The catkin begins to take on a brownish color and at length the whole catkin, in case it is staminate, drops off. If it is androgynous, the staminate part drops off, or withers.

These male sterile trees appear to have a normal, sometimes excessive, development of the females, and are quite prolific nut producers. Information on the occurrence of female sterility in the hybrid trees is incomplete, but the indications are that at least partial sterility is frequent.

2. _Triploid Hybrid_

In 1934 we produced a cross of Chinese and American chestnut which proved to be unusual in several respects. The leaves are enormous--9 inches to 1 foot in length, and 4 or 5 inches in width. The hybrid is not particularly blight resistant but more so than its American parent. It died back from the blight about 1940 and the present tree has developed as a shoot from the old roots. The growth is rapid and vigorous. The flowers appear normal, but we have never been able to make a cross with its pollen, nor to effect fertilization of its pistillate flowers. It may be triploid, that is, with 3 sets of chromosomes instead of the normal double set, and this would account for its barrenness.

In the spring of 1952 some of the vigorous shoots of this tree were successfully grafted on shoots from an old stump of Chinese chestnut, using the veneer crown graft method. The scions had not been taken when dormant, but were transferred directly from the tree to the stock in late April. This grafting was done in order to impart greater resistance, if possible, to the CA hybrid by means of the roots of the Chinese stock.

3. _Systemic Defect_

Since the early 1930's we have seen occasional individuals with abnormal foliage--somewhat mottled, usually curled and often misshapen. Thinking that a virus might be the cause of this trouble the senior author tried grafting some of the shoots on to healthy stocks. The grafts were in no case successful because the scions were too weak. Finally he succeeded in grafting a branch from an affected tree on to a branch of a normal individual. The only result was an increased vigor of the healthy branch. This year he rubbed juices from leaves of such an abnormal individual on to wounded healthy leaves, without result. Moreover, such sick individuals, although growing for years close to healthy trees, have never communicated the malady to their neighbors. Growth is comparatively slow, and there is much dying back or dying out of the slender branchlets.

The evidence indicates that this is _not_ a virus trouble, but a systemic defect, probably caused by chromosome aberration or gene abnormality. It is significant that this trouble occurs only in hybrids. Such trees never flower. We have known four such cases, two of which are now dead. Similar types appear in other species as inherited deviations from normal.

Insect Injuries

A heavy attack from the spring canker worms developed in 1951, but spraying with DDT on May 24th prevented serious damage. No outbreak of canker worms appeared in the spring of 1952. The Japanese beetle has been very little in evidence. The principal bad actors are the mites, _Paratetranychus bicolor._ Although barely visible to the naked eye, the effect they produce of whitening the leaves is conspicuous, especially on the Chinese chestnut and its hybrids. These insects overwinter in egg form on the surface of the bark. Last winter they were so numerous on some of the trees that the bark had taken on a red color--especially on smooth-barked trunks just below a branch. An application of "Scalecide" on April 21, while the trees were still dormant, followed by two heavy applications of "Aramite" (6-7 lbs. per acre) on June 13th and 27th, gave good control for the rest of the summer. Spraying with DDT for weevils was done on August 18th and September 3rd in 1952 with good results.

Cooperative Hybrid Chestnut Plantations

In 1947 the first hybrid chestnut plantation under forest conditions was made in cooperation with the U.S.D.A. Bureau of Plant Industry, Division of Forest Pathology. The plantations are made in order to test the hybrids under normal forest conditions and different climatic conditions. In general, each plantation consists of about 100 trees, 50 U.S.D.A. hybrids and 50 Connecticut hybrids. The trees are planted at a 10' by 10' spacing, and the overstory is girdled at the time of planting in order to give the plants better light conditions without causing an abrupt change in the microclimate of the forest floor--a method developed by Dr. J. D. Diller of the Division of Forest Pathology (1). Ten plantations at 9 locations have been established since 1947. These are listed below:

No. of Plots Location Year Established
-------------------------------------------------------------------
1 Edward Childs Estate, Norfolk, Conn. 1947
1 Tennessee Valley Authority, Norris, Tenn. 1947
1 Table Rock State Park, Pickens, S.C. 1948
1 Antioch College, Yellow Springs, Ohio 1948
1 Upper Perkiomen Valley Park, Green Lane, Pa. 1949
1 So. Ill. Univ. Fish & Wildlife Service, Cartersville, Ill. 1949
1 Russ State Forest, Decatur, Mich. 1951
2 Nathan Hale State Forest, Coventry, Conn. 1951
1 Ouichata Nat'l. Forest, Hot Springs, Ark. 1952
-------------------------------------------------------------------

Connecticut State Ownership of Sleeping Giant Plantations

On April 11, 1951, at a meeting at the "Little Red House", Sleeping Giant Mountain, the lands on the Sleeping Giant Mountain, Hamden, Connecticut, about 10 acres, on which about 1500 chestnut trees are now growing, including nearly every chestnut species known to science, and many valuable, blight resistant hybrids, were formally deeded over to the State of Connecticut by their owner, the senior writer of this report. The meeting was attended by officials of the Sleeping Giant Park Association, the Connecticut State Park and Forest Commission, The Connecticut Agricultural Experiment Station, and the Yale School of Forestry. The transfer to the State was made with the understanding that The Connecticut Agricultural Experiment Station would continue the chestnut breeding work. The whole region is now undergoing a fairly rapid housing development, and in the ordinary course of mortal events this plantation would have been divided into building lots within the next few decades. The State ownership will obviate this, and The Connecticut Agricultural Experiment Station sponsorship will assure a continuation of the breeding work.

Literature Cited

1. Diller, J. D. Growing chestnuts for timber. 37th Ann. Rept. of
Northern Nut Grower's Assn. for 1946. 66-68. 1947. 2. Graves,
Arthur Harmount. A method of controlling the chestnut blight on
partially resistant species and hybrids of _Castanea_. 41st Ann.
Rept. of Northern Nut Growers Assn. 1950. 149-151. 1951. 3. Hauser,
Willibald. Zur Physiologie des Gerbstoffes in der Pflanzenzelle.
III. Protoplasma 27:125-130. 1936-37. 4. Nienstaedt, Hans. Tannin
as a factor in the resistance of chestnut, castanea spp., to the
chestnut blight fungus, _Endothia parasitica_. Phytopathology
43:32-38. 1953. 5. Nierenstein, M. The natural organic tannins. J.
& A. Churchill.

FOOTNOTES:

[Footnote 18: Also of The Division of Forest Pathology, U.S.D.A., Plant Industry Station, Beltsville, Maryland.]

[Footnote 19: Records furnished by the U.S. Weather Bureau at New Haven, Conn.]

[Footnote 20: October, 1952, was among the six driest Octobers on record. These were: 1879, 1892, 1897, 1916 and 1924. From U.S. Weather Report, New York City.]

Effect of Vermiculite in Inducing Fibrous Roots on Tap-Rooting Tree Seedlings

HERBERT C. BARRETT[21] and TORU ARISUMI[22]

When seedlings of nut trees and other tap-rooted species are transplanted from nursery to orchard, the percentage of survival in often quite low. Perhaps the chief reason for this failure is the marked and pronounced tendency of most tap-rooted plants to produce little or no fibrous, branched roots in lieu of the long, straight, and seldom branched tap roots.

The common practice of undercutting seedlings during the dormant season to induce a branched root system requires additional labor, and often results in reduced growth and vigor during the following season. The use of hardware cloth or other close-meshed wire is effective, but this method also has the disadvantage of being relatively expensive for the nurseryman.

Preliminary work carried on during the past two years has shown that with certain nut trees and other tap-rooted plants, it is possible to induce fibrous roots by growing such seedlings in vermiculite. The methods and results of this work are presented in this paper.

Material and Methods