Bluemont, Va., we had 2500 numbered trees under observation; about 1500
of them being sprayed. Equal numbers of trees were sprayed with Bordeaux
and with lime-sulphur. The number of sprayings given different lots of
trees varied, but even trees sprayed as often as every fifteen days
blighted in a number of instances. While I did not get a greatly reduced
percentage of blight (approximately 50 per cent) among the sprayed trees
taken as a whole, the difference between individual plots seemed to
depend rather on location in the orchard, as some blocks of unsprayed
trees showed practically no blight and some blocks of sprayed trees
showed considerable blight. I might say that the grafted trees did not
blight nearly so heavily as the ungrafted trees. So far as any real
success is concerned there was none. It would cost over one hundred
dollars per acre per year to spray as often as some of the trees were
sprayed, and it wouldn't control the blight. So I wouldn't consider it
at all practicable.
THE SECRETARY: What is the reason that the grafted trees blighted less
than the ungrafted?
MR. HUNT: Well, I wouldn't pretend to say as to that, except that it is
so. I had each tree numbered and kept an individual record of all the
trees, and I found--I have forgotten the exact figures--but there was
about three-fifths as much blight among the grafted trees as among the
ungrafted trees. Of course, they are an imported variety, I believe, and
it may be that on that account they may have developed some resistance.
But Mr. Van Fleet may know more about that.
DR. METCALF: There seems to be some evidence that the imported European
varieties have a slight degree of resistance, not enough to count, but
enough to show in that fraction that Mr. Hunt gave.
THE SECRETARY: It is only a varietal condition, then, not from the fact
of grafting, but simply because of a different variety?
MR. HUNT: Oh, yes, I think so.
MR. LITTLEPAGE: Mr. President, in view of this information about the
chestnut, is there the slightest use in the world for this Association
to encourage anybody to plant chestnuts anywhere in the United States?
THE PRESIDENT: Dr. Kellerman is here, and I wish to refer to him Mr.
Littlepage's question with a slight addition. Is there, first, any
prospect of any place staying immune? Second, would it not be to the
advantage of the country if the sale of chestnut stock were stopped?
DR. KARL F. KELLERMAN: Mr. President, to answer those questions involves
a rather large contract on my part. (Laughter). In the first place, the
problem of growing and marketing chestnuts, I think, is one that I could
hardly be expected fairly to discuss. I am here rather to explain the
attitude and action of the Federal Horticultural Board than to try to
give any constructive advice to the nut growers.
The Federal Horticultural Board is a board of five men to advise the
Secretary of Agriculture in establishing plant quarantines, either on
the introduction of plant material into the United States, or on the
movement of plant material inside the United States within the
quarantined areas. The Horticultural Board, therefore, has to deal more
with actual conditions than with outlining such policies as your
chairman has asked me to outline.
THE PRESIDENT: Excuse me, Dr. Kellerman, but we wish to know if there
is, in your opinion, any prospect of any region remaining immune?
DR. KELLERMAN: Well, even that is going rather further than I would like
to go, and yet the negative answer to that question is practically the
basis on which the Federal Horticultural Board decided that it was
impracticable to quarantine infected areas at the present time. The
evidence at hand appears to indicate conclusively that if the trees
that are to be grown are distinctly susceptible to the disease they will
almost certainly have an opportunity to become infected, no matter what
part of the United States they may be grown in. Now, whether that
infection would be a matter of a few months, or a few years, or a few
decades, of course, would be altogether a matter of chance, but, with
the wide distribution of nursery stock that is infected, with native
chestnuts rather generally infected and continuing to be infected, and
with practically no chance of preventing the continuation of the disease
in the native chestnuts, abundant sources for infection of susceptible
material appear to exist. For that reason, it appears to be, from an
economic standpoint, inadvisable to attempt to check the disease through
the establishment of quarantines.
THE PRESIDENT: Dr. Kellerman, you have answered my first question to
perfection, and now I want to ask the second one. If this blight is
practically a sure-kill, isn't it wrong to permit people to spend money
in the hope that, in some way, they are going to escape it? And if that
is the case, why shouldn't the whole traffic in chestnut trees be
stopped, with the possible exception of experimental things, which might
be allowed with the direct permission of some governmental board?
DR. KELLERMAN: That is a question that is very much harder to answer.
There might be favored regions where orchard culture of the chestnut
could go on for a considerable term of years before infections became
general and before the industry would be stifled because of this
disease. That is merely a matter of conjecture, as I see it. We have so
little evidence as to the speed with which a paying orchard business can
be developed in a new locality, so little evidence as to how the disease
may act under widely separated climatic conditions, that I don't feel
that we are prepared to say definitely that the industry is bound to
fail in every place where it is tried. Personally, I think that it ought
to be considered only on an experimental basis, but that represents
merely my personal opinion, and I doubt whether there is any effective
means for establishing a policy of that sort. It might be possible for
the general advice to be given that there was danger in any orchard
planting of chestnuts, no matter where it might be undertaken, and of a
comparatively rapid loss through the chestnut blight. I doubt whether
more than that would be feasible.
THE PRESIDENT: I have been enthusiastic over the chestnut for twenty
years this season, and these are matters in which I am greatly
interested. As I see it, the problem is one that is really much bigger
than the chestnut. The whole field of nut growing, which is now on the
edge of great accomplishments, is likely to be seriously injured,
because the most conspicuous thing in nut growing is the taking
advertisement of the firm whose bad trees have been referred to by Dr.
Metcalf. I think we do not appreciate the seriousness of the situation.
The firm Dr. Metcalf referred to is selling trees that are diseased in
places where they are sure to die quickly. Other men are similarly
selling trees, with less skillful advertising, perhaps, but probably no
less diseased. Most of these nurserymen may be honest in their belief
that they are putting out stock that is not diseased. But in the infant
trees it is almost impossible to detect the blight, so that the tree
goes out looking like a perfectly good one. It may be two or three
seasons before it dies.
Now, the economic aspects are these: Who should stand the loss, the man
in the nursery or the man in the orchard? It is a toss-up, it seems to
me at present, with the results apparently in favor of the nurseryman
rather than in favor of the citizen. The people who have an interest in
nut growing are going to have that interest lessened or destroyed by
beginning with a bad kind of tree. There are possibilities of a great
national injury, as I see it, if we let this thing go on.
DR. KELLERMAN: Well, as a constructive policy for aiding in the
establishment of nut culture, I think your policy is sound, but as a
question of economics of operation, I doubt whether any plan of that
sort can be established, beyond the plan of merely giving the general
advice that such planting is attended with very grave risks.
THE PRESIDENT: Have you not authority, or does not authority exist, to
prohibit shipment?
DR. KELLERMAN: The plant quarantine act gives the Department authority
to quarantine infected areas and to place certain restrictions on
shipments. To place any such restriction, however, it must be plainly
established that beneficial results are going to result, not to a
particular industry necessarily, but to the general public. The
difficulty in establishing a quarantine on the shipment of nursery stock
is the apparent impossibility of saying that that is going to stop the
spread of the disease. That is one question. The other problem is the
difficulty of determining what is infected territory and what is not.
We have very serious difficulty in making regulations, excepting as
between definitely infected territory and definitely clean territory.
THE PRESIDENT: And you don't have the authority to make a sweeping,
blanket prohibition of the shipment of a certain thing?
DR. KELLERMAN: No, we haven't that authority.
MR. M. P. REED: We put a clause in the printed matter that goes out with
all of our shipments saying that chestnuts are subject to blight, and
that we don't recommend their planting. I think if nurserymen all
followed that principle everybody would buy with their eyes open.
THE PRESIDENT: I am sorry you are so lonely in the business. (Laughter.)
MR. LITTLEPAGE: As regards the possibility, or the impossibility, of
doing any good to the chestnut industry by quarantining it, I fully
agree with Dr. Kellerman. I think any attempt of the Board to
quarantine, so far as benefit to the prospective chestnut grower is
concerned, is perfectly useless.
DR. ROBERT T. MORRIS: It seems to me it may be resolved into a very
simple proposition. Now, chestnuts may be raised in orchard form if we
spray with Bordeaux mixture, and cut out blight when it appears. I do
it. They live. Those that are not sprayed die, unless given tiresome
attention. That settles that question for my part. Chestnuts may not be
raised in forest form because it does not pay to spray and cut to that
extent. But chestnuts may be raised profitably in orchard form by people
who are willing to take the trouble to spray them, and to cut out blight
early. It seems to me that people should be properly warned that they
may plant chestnuts in orchard form provided they are willing to look
after them, otherwise we ought to guard against the public buying
chestnut trees, unwarned.
MR. LITTLEPAGE: Dr. Morris, were you in when Mr. Hunt made his
statement?
DR. MORRIS: I got in late.
MR. HUNT: I sprayed fifteen times, every two or three days during the
blossoming season.
DR. MORRIS: I used arsenate of lead with my Bordeaux mixture for the
reason that it is convenient. That makes it stick ever so much tighter.
Now, that may be a feature of my confidence. Three or four heavy storms
will not wash off my Bordeaux mixed, applied in that way, with arsenate
of lead.
MR. HUNT: Well, my trees are dying right along.
DR. MORRIS: I am right in the midst of the worst chestnut blight
conditions. The only kinds I have that are not blighted are sprayed
trees, and chestnuts of kind that resist the blight. I had twenty-six
kinds from different parts of the world to test out in the blight
question. One kind from Manchuria is very blight-resistant. I find that
our American chinquapin, both our eastern form and the western tree form
are both blight-resistant. Also the alder-leaf chestnut. That is my
experience. Those four chestnuts are practically immune, and on my
property American chestnuts dying all around them.
I have one particular variety of American chestnut that I think a great
deal of. It was one of the first trees to go down from the blight. Stump
sprouts from this tree I have grafted on other stocks, on the common
American, and recently on chinquapin. The sprayed ones are all alive;
the unsprayed ones are not alive. Now, that is a matter of locality,
perhaps.
THE PRESIDENT: Dr. Morris, I detect a possible explanation for
difference of results. Mr. Hunt's trees were sixteen or seventeen years
old. Dr. Metcalf tells us, however, that young trees are relatively
immune. How old are yours?
DR. MORRIS: Not over twelve years. No grafts on them over four years.
That would make a difference.
MR. LITTLEPAGE: Well, Mr. Hunt did a good job of spraying. I saw his
trees, and they were saturated.
MR. WEBER: Do they ever use a sticker in the Bordeaux?
A MEMBER: What preparation of Bordeaux mixture do you use, Dr. Morris?
DR. MORRIS: I use a commercial preparation called Pyrox.
MR. CARL J. POLL: Will the chestnut blight attack any other trees
besides the chestnut?
DR. METCALF: Outside of the chestnut genus, that is, the genus Castanea,
the disease goes on to a few other trees. A curious fact is that it will
go on to the sweet gum, a tree not related at all, and it will go on to
a few oaks, in no case enough to seriously damage them as it does the
chestnuts, but enough so that those trees can easily be carriers of the
disease.
THE PRESIDENT: I think we might pass from this funeral. We have a paper
by Dr. Van Fleet, whose work, I suppose, is known to everybody here. The
paper has been prepared by Dr. Van Fleet and will be read by the
Secretary.
HYBRIDS AND OTHER NEW CHESTNUTS FOR BLIGHT DISTRICTS.
DR. WALTER VAN FLEET, WASHINGTON, D. C.
The sinister spread of chestnut blight, as the bark disease caused by
the fungus _Endothia parasitica_ is popularly called, within little more
than 10 years, from its place of apparent origin near New York City into
13 states, practically reaching the eastern and northern limits of our
native chestnut stands, and sparing in its course no individual trees
exposed to infection, has about convinced even the most optimistic
observers that without the intervention of natural checks the American
chestnut as a forest asset will soon pass away. There is no present
indication of diminution in the virulence of the fungus parasite and
little reason to hope its progress as a timber destroyer can be stayed
by any agency in the control of man. Already the losses, direct and
indirect, occasioned by chestnut blight are computed as high as
$50,000,000, about half of the estimated value of the entire stand.
With the very reasonable assumption that our native chestnut is doomed
to virtual extinction it is well to consider in time if it can be
replaced as a timber and nut-producing tree by other chestnut species or
combinations of species less subject to injury by this disease-producing
organism. The Endothia fungus, as a destructive parasite, is apparently
confined to the chestnut, rarely if ever harmfully affecting genera even
as closely allied as the oak (Quercus) or Castanopsis. Of the various
species of chestnut or Castanea those native to Japan and Central China
appear most resistant, probably having been for ages accustomed to the
presence of the fungus, while the European chestnut, _Castanea sativa_,
our native _C. Americana_, and our chinquapin, fall easy victims when
exposed to infection. Of the Asiatic forms _Castanea crenata_ of Japan
and Eastern China and _C. molissima_ of the interior are most promising
in this respect, though the latter is still an almost unknown quantity
as regards cultivation in this country.
_Castanea crenata_, commonly known as Japan chestnut, in its more
typical forms is highly resistant, so seldom showing material injury
that, for practical purposes, it may be regarded as immune. Japan
chestnut seedlings raised from nuts grown in proximity to our native
chestnut and exposed to the influence of its pollen are at times more
seriously affected, but are rarely destroyed by the bark disease. The
Japan chestnut is of comparatively low growth, of small value for timber
purposes, but as a nut-producer is very fruitful and precocious, bearing
great crops at an early age. The nuts are often very large but usually
of poor quality. The species, however, proves quite plastic in the hands
of the plant breeder, being readily modified in the directions most
desired by the ordinary methods of cross-pollination and selection. It
freely hybridizes with all other chestnut species and varieties that
have been tried, and forms the basis of the most hopeful work in
breeding for disease-resistance that has yet been attempted.
_Castanea molissima_ is of much taller growth and bears nuts of moderate
size, but of really good quality in the types that have reached this
country. It can be infected by _Endothia parasitica_ but the disease
progresses slowly and in some instances results in little harm. The
species has been so recently established in America that practically
nothing is known of its breeding capabilities, but if its
disease-resistance under our climatic conditions is assured it would
appear most hopeful material for replacing our vanishing native species.
Explorers report there is a still more promising chestnut in China,
reaching nearly 100 feet in height under forest conditions, but it has
not yet been secured for trial in this country.
_Castania sativa_, the commercial chestnut of Europe, in many varieties
has long been cultivated in America and for nut production is without
doubt the best of the well-known exotic species. It has no great timber
value, however, and its disease-resistance, though higher than _C.
Americana_, is scarcely great enough to warrant extended use as breeding
material.
The native chinquapin, _Castanea pumila_, in its bush and tree forms
remains as the only promising chestnut not found in the Orient. While
readily inoculated by artificial means, the chinquapins, especially
varieties of the northern bush forms, quite often escape natural
infection, doubtless because of their small size, smooth bark, and less
liability to insect attacks.
Chestnut breeding for nut improvement, chiefly by selection of native
European and Japanese species, has been carried on in several diverse
localities in the United States, with distinctly promising results but
inter-pollinations have also been effected between most species and
varieties, the outcome indicating that rapid improvement along the
desired lines may be expected from crossing the really desirable types.
In 1903 and succeeding years the writer made many careful pollinations
of the native chestnut and the bush chinquapin with European and
Japanese chestnuts in many varieties. Some hundreds of seedlings
resulted, mostly showing a high level of promise as judged by their
initial thrift and vigor of growth, but the appearance in 1907 of the
Endothia disease among the plantings soon put an end to the work with
the native and European chestnuts, as, with scarcely an exception, they
quickly became infected. The crosses of chinquapin and Japan chestnut,
however, showed considerable resistance as a whole, and a number of
individuals have resisted infection until the present time, though
constantly exposed to the disease, both at their locality of origin in
New Jersey and since at Arlington farm, to which they were transferred
in the second and third years of growth. Others have been attacked in
greater or less degree, but show great powers of recuperation, sending
up suckers that often fruit well by the third year. The resistant
varieties show great promise as nut producers, coming into bearing when
three or four years old from seed and producing abundant crops of
handsome nuts, of excellent quality, four to six times as large and
heavy as those borne by the chinquapin parent, ripening in early
September before chestnuts of any kind have appeared in the market.
These nuts have thicker shells than other chestnuts, are much less
subject to attacks of the chestnut weevil and preserve their fresh and
inviting appearance longer when gathered. The flavor varies somewhat
according to the particular pollen parent of the different varieties,
but is always agreeable in the fresh state when the nuts are properly
cured. When boiled or roasted they are particularly sweet and pleasant
to the taste.
The trees are quite vigorous in growth, considering their rather dwarf
type, reaching 10 or more feet in height at 6 to 8 years from the
germination of the seeds and with scarcely an exception bear regular and
increasing crops after the third year. Propagation of the most promising
varieties has been effected by grafting and budding on _Castanea
molissima_ seedlings as resistant stocks, but it cannot be said that
these processes, when performed under greenhouse conditions, give ideal
unions. It is hoped to make fairly extensive trials of _C. molissima and
C. crenata_ as stocks for field grafting the coming season.
But the most encouraging feature of these chinquapin-crenata crosses is
the excellence of their seedlings as grown from chance or
self-pollinated nuts. Fifteen direct or second generation seedlings and
one of the third generation have fruited to date. All have retained in
growth and fruitage the characters of their immediate parent and it
almost appears as if the good qualities of these hybrids may be
perpetuated from seeds, thus dispensing in a great measure with
vegetative propagation--always costly and uncertain with nut trees.
Several hundred of these seedlings are under observation and it scarcely
appears too much to hope that they may inherit the disease-resisting
character of their parents as well as other desirable qualities.
Selection work with a precocious strain of Japan chestnuts of apparently
pure type has been continued through 4 generations of seedlings after an
initial cross-pollination of two particularly desirable varieties had
been made in 1903. These seedlings show greater range of variation than
the hybrids with chinquapin, but all bear nuts of marketable value in 2
to 4 years from germination. None have been attacked by the Endothia
fungus, though many have constantly been exposed to infection.
Notwithstanding their extreme precocity trees of this Asiatic strain
grow steadily and if thickly planted in favorable localities may in time
produce timber of local value, but it is to the taller growing species
of middle China that we must look for material to replace our vanishing
native forest stands. The preservation in this country of the chestnut
as a nut-bearing tree appears assured in view of the progress already
made and it should not be too much to hope that resistant strains of the
timber type may yet be developed by systematic breeding experiments.
* * * * *
THE PRESIDENT: Inasmuch as the author of the paper is not present to
answer questions, the only thing that may be done is to ask further
contributions of knowledge in the same field. Has anyone any
contribution to make?
MISS LOUISE LITTLEPAGE: I would like to ask how long the chestnut tree
has been able to live with the blight?
DR. METCALF: Do you refer to the Asiatic ones or to the ones that grow
here in America?
MISS LITTLEPAGE: The American.
DR. METCALF: It is almost impossible to answer that question because you
have to define just what you mean by "living." If the chestnut tree is
attacked first or early on the trunk, it is girdled and dies shortly,
but if it is attacked first on the top there develop conditions like
what is shown in this picture (showing photograph). I am not certain
that you can see these bunches of suckers a little way up the tree. Now
those trees will sometimes exist four or five years. I can say safely
that I have seen trees last five years.
DR. MORRIS: I can add three years to that.
THE PRESIDENT: If there is no further discussion, we may adjourn.
* * * * *
FRIDAY, SEPTEMBER 8TH, AT 8.15 P. M.
Meeting called to order by the President.
THE PRESIDENT: To my mind nut growing is part of a larger field, a field
of conservation, one which is going to develop a whole new series of
tree crops, of which the nuts are but a part.
PRESIDENT'S ADDRESS.
DR. J. RUSSELL SMITH.