FILBERT OR HAZELNUT.
Corylus, _Tournefort_. Name from _korys_, a hood, helmet or bonnet,
in reference to the form of the calyx or husk enclosing the nut.
Order, _Corylaceae_. Deciduous trees or low shrubs. Male flowers
appearing in the autumn in pendulous cylindrical catkins two inches
or more in length, with a two-cleft calyx partly united with the
bracts or scales. These catkins remain on the plants all winter,
becoming fully developed, and shedding their pollen early the
following spring. Female flowers minute, entirely hidden within the
buds during the winter, but early in spring their bright red,
thread-like stigmas push out from the tips of the lateral or
terminal buds. Ovary two-celled, with one ovule in each. Nut
globular, ovoid or oblong, often in clusters, but each enclosed in a
leafy, two- or three-valved husk, fringed or deeply notched at the
upper end. Leaves broadly heart-shaped, serrate, with sturdy, short
leaf-stalks. The filbert and hazel always bloom before the leaves
appear in spring, and the male catkins usually open and begin to
scatter their pollen in this latitude during warm days in March, the
females soon following, their bright-red stigmas pushing out from
the ends of the buds, but as soon as fertilization has been
consummated they shrivel and disappear. The trees may then remain
leafless for weeks following, and yet produce a heavy crop of fruit.
[Illustration: FIG. 37. LARGE FILBERT.]
The common English name, filbert, is from "full-beard." All the
varieties with husks extending beyond the nut, and with fringed
edges, are filberts (Fig. 37); while those with husks shorter than
the nuts (Fig. 38) are hazels, from the old Anglo-Saxon word,
_haesel_, a hood or bonnet. The parentage, size, form or quality of
the nut, is not to be considered in this classification, for when
the nuts are ripe and fallen from the husks, there is nothing left
to distinguish the hazelnuts from filberts, unless a person is
sufficiently familiar with a variety to know to which group it
belongs. In France these nuts are known under the general name of
_Noysette_; while in Germany it is _Haselnuss_; in Holland
_Hazelnoot_; and in Italy _Avellana_, from Avellana, a city of
Naples, near which there is a valley where these nuts have been
extensively cultivated for many centuries.
[Illustration: FIG. 38. LARGE SEEDLING HAZELNUT.]
=History of the Filbert.=--It is claimed that the filbert was first
known to the Romans as _Nux Pontica_, because introduced from
Pontus; but it must have become naturalized throughout southern
Europe in very early times. But the Italian name of _Avellana_
appears to have been applied to the wild hazel of Britain, long
before Linnaeus adopted it as the specific name of the indigenous
species. John Evelyn, one of the most careful and learned of English
arboriculturists of his time, in referring to these nuts, in his
"Sylva," 1664, says: "I do not confound the filbert Pontic,
distinguished by its beard, with our foresters or bald hazelnuts,
which, doubtless, we had from abroad, bearing the names of _Avelan_
or _Avelin_, as I find in some ancient records and deeds in my
custody, where my ancestors' names were written Avelan, _alias_
Evelin."
The filbert has been celebrated in prose and poetry from ancient
times, as we may infer from a remark of Virgil, who says that it has
been more honored "than the vine, the myrtle, or even the bay
itself" (Eclogue vii).
The supposed occult power of a forked twig of the hazel as a
divining-rod (_virgula divinatoria_) for finding hidden treasures,
veins of metals, subterranean streams of water, and even pointing
out criminals, is, of course, purely mythical, although so solemnly
attested by many learned men in the past; and I would not consider
this myth worthy of a notice here were it not for the fact that it
was early imported into this country, and is still firmly believed
by many persons among our rural population. It is true that the
supposed attributes of the European hazel have been transferred to
different plants in this country, mainly to the peach and our
indigenous witch-hazel (_Hamamelis Virginiana_), but the myth still
lives, a legitimate descendant of an Old World nut tree.
There is little to be said in regard to the history of the filbert
and hazelnut in this country, but it is quite likely that both of
the European species, and many varieties, were brought here and
planted by the early settlers in the Eastern States, and bushes of
the same could have been seen in many gardens a hundred years ago;
but I have been unable to find any account of extensive plantings of
these nuts, although nurserymen, all along, have been offering
choice varieties to their customers. In the main, our pomologists
have either remained silent in regard to these nuts, or, at most,
referred to them very briefly in their published works.
William Prince, of Flushing, N. Y., in a "Short Treatise on
Horticulture," published in 1828, refers to the filbert as follows:
"This shrub or, in some cases, tree, accommodates itself to
every exposition, and to every variety of soil, but prefers a
moist loam on a sandy bottom, with a northern exposure. It is
easily multiplied by seeds, layers or inoculation. In fact,
these nuts, which are vended in large quantities in our markets,
grow as well in our climate as the common hazelnut, and produce
very abundantly. Such being the case, it is hoped, ere long,
sufficient will be produced from our soil to supersede the
necessity of importation, as plantations of this tree would
amply remunerate the possessor; or if planted as a hedge, would
be found to be very productive. A single bush of the Spanish
filbert in my garden has produced a half-bushel annually."
Mr. Prince then names a few of the best varieties, which are about
the same as those recommended at the present time, and he was, no
doubt, honest in recommending filbert culture to his countrymen, for
his own limited experience proved that the trees would grow here and
fruit abundantly.
A. J. Downing, in the first edition of his "Fruits and Fruit Trees
of America," 1845, says: "The Spanish filbert, common in many of our
gardens, is a worthless, nearly barren variety; but we have found
the better English sorts productive and excellent in this climate
(Newburg, N. Y.), and at least a few plants of these should have a
place in all our gardens." If a few plants will succeed in a garden,
then we might reasonably suppose that the number might be safely
increased, and this was the idea of Mr. Prince, and many other
writers on the subject since his time, but I fail to find any record
of extended experiments with these nuts in this country, and as
there must be some good reason for this neglect, perhaps my own
experience in the cultivation of the filbert and hazel, to be given
in succeeding pages, may throw some light on this question.
=Propagation.=--Filberts are readily propagated by almost all the
modes employed in the multiplication of ordinary fruit trees and
shrubs. The nuts are not at all delicate, and may be planted in the
fall, or stored in a cool place, mixed with sand or sphagnum, and
then put out in spring, always selecting a rather light and rich
soil for a seed bed, and in such beds plants from one to three feet
high may be obtained the first season. The seedlings produce such a
mass of fine roots that they are readily transplanted without danger
of loss. Varieties are perpetuated and multiplied by budding,
grafting, suckers, layers, and some grow quite readily from cuttings
made of the young, vigorous shoots, cut up into proper lengths in
the fall, and then buried in the ground until the following spring,
then planted out in trenches, as usually practiced with currants,
grapes and similar plants. The method of propagation most generally
practiced in Europe and this country is by suckers, and as the
cultivated varieties of the filbert usually produce these from the
base of their stems in profusion, there is no lack of material;
besides, they make as strong, healthy and productive plants as can
be procured in any other way. To secure an extra number of roots on
these suckers, they should be banked up with a few inches in depth
of good rich soil, or old manure, about midsummer, and then late in
the autumn dig down to the base and remove with knife or chisel,
after which they may be headed down to about fifteen or eighteen
inches, and heeled-in for the winter, to be planted out in nursery
rows early in spring. If a greater number of sprouts are wanted than
the plants naturally produce, the main stem may be cut down; but
this will seldom be necessary, because the young transplanted
suckers will usually produce more or less new ones the first season,
all of which can be utilized for multiplying the stock if they are
wanted.
=Soil, Location and Climate.=--European varieties of the filbert
thrive best in what may be termed a rich loam, with a dry subsoil.
If the soil is too moist, the trees are inclined to run too much to
wood, producing less fruit. In the famous nut orchards of Kent,
England, the soil is loam upon a dry, sandy rock. The trees in these
orchards are manured at least once in two years, especially after
they reach the full bearing age. Almost any good soil that is rich
enough to produce a good crop of corn, and is not submerged in
winter, will answer for the filbert in this country.
In selecting a location for a filbert orchard, an open, airy one
would probably be preferable to a spot so sheltered as to cause the
flowers to appear so early as to be injured by frosts. Furthermore,
I would warn cultivators to keep as far away as possible from any
hedgerows or plantation of the wild native hazel bushes, for these
are always loaded with disease germs that are fatal to the foreign
species. We might reasonably suppose that filberts would succeed
better in the Southern than in the Northern States, but if the
experience of those who have tried them there count for anything,
then these nuts are not adapted to the South, owing to the fact that
the flowers almost invariably push out during warm days in winter,
and these are destroyed later by frosts. In the more elevated
regions of the northern border of the Southern, and in similar
locations in the Middle States, these nuts will doubtless thrive, or
at least the climate will prove congenial. The more equable the
climate and free from extremes in temperature, the better; but the
most important element in this country is moisture, especially in
summer, when the nuts are filling out; and the best way to supply
this, where irrigation cannot be practiced, is to keep the ground
around the trees continually covered with a mulch of leaves or other
coarse vegetable matter.
=Planting and Pruning.=--The space to be allowed between the plants,
when set out for bearing, will, of course, depend very much upon the
size they are expected to attain. Those varieties which assume and
remain in the bush form may be planted very close together, or not
more than six to eight feet between the plants; but those which
become small trees must be given more room. The larger European
sorts, which are at present the only ones worth cultivating for
their nuts, should be set ten or twelve feet apart, and the rows
fifteen to sixteen feet, then if properly pruned they will shade the
ground and be in a convenient form for gathering the crop. The trees
may be planted in the orchard when quite small, and some kind of
vegetable crop grown among them for the first two or three years,
but I would prefer keeping the plants in nursery rows until they
were four or five feet high, and then transplant to the orchard, and
set a short, stout stake by the side of each, to keep the main stem
in an upright position until the tree is well established.
The first pruning,--except removing suckers from those in the
nursery rows,--will be the heading back of the main or central stem
to a hight of two or three feet, for the purpose of laying the
foundation, as it were, of the head of the future tree. Three or
four of the larger branches, which will push out from near the top
of the severed main stem, are to be selected to form the top, and
all others removed. Small lateral branches or twigs will spring out
from the larger or main ones, and in this way the head of a bearing
tree is formed. But before attempting to prune a mature or fruitful
tree, we must consider the mode of fructification, for the filbert
does not bear nuts on the young growth of the season, as in the
chestnut, but on the small branchlets or spur-like twigs of the
preceding season, or, as we may say, on the one-year-old twigs. The
small fruiting twigs are seldom more than four to six inches long,
and sometimes almost every well-developed bud on these contain
pistillate flowers and embryo nuts, either singly or in clusters. In
pruning the bearing trees, the main point to be observed is to head
back the strong leading shoots, to prevent the trees growing too
tall, as well as to force out the side or lateral twigs as fruiting
wood for the ensuing year. If the heads of the trees become too much
crowded to admit light and air to the center, some of the larger
branches must be removed entire. The best time to prune is in early
spring, when the trees are in bloom, for at this season we can
readily determine the injured from the sound male catkins, and
preserve enough of these to insure perfect fertilization. It is not
necessary, however, that there should be healthy pollen-bearing
catkins on every tree in an orchard, for if one in a dozen is well
supplied, there will be sufficient to fertilize the flowers of all
growing near by. It often happens, in our rather severe climate,
that the catkins of some trees or varieties are winterkilled, while
the pistillate flowers enclosed in the buds escape injury, and when
this occurs it is well to have some hardy variety at hand, from
which pollen can be obtained when needed. The inferior varieties are
usually the most hardy, and the wild European hazel or our northern
beaked hazel, will usually escape injury where all the large
improved sorts fail, and it requires but a few minutes' labor to cut
branches bearing sound catkins, and scatter these about through the
heads of trees requiring such assistance to make them fruitful.
SPECIES OF AMERICAN HAZELS.
CORYLUS AMERICANA (Walters). Common hazel bush.--Leaves roundish,
heart-shaped, pointed, coarsely serrate; husk somewhat downy, with a
wide, flattened, fringed border extending beyond the roundish nut.
Shell rather thick and brittle; kernel sweet and good, but the nut
is too small to be considered of much value. A low shrub, with many
stems springing from the roots. Young shoots and twigs downy and
glandular-hairy. Common in woods and old fields from Canada to
Florida.
CORYLUS ROSTRATA (Aiton). Beaked hazel.--Leaves ovate or oblong,
somewhat heart-shaped, pointed, doubly serrate; husk extending an
inch or more beyond the round or ovoid nut, forming before it opens
a long tubular beak, hence the name. The husk is densely covered
with nettle-like bristles, which are quite irritating to tender
hands. The nuts are small, usually growing in clusters at the ends
of the twigs, only a few coming to maturity. A low shrub or small
tree, usually growing in a dense clump, not spreading from
subterranean stems, as in the last species. Common on rather firm
and rich soil along the borders of streams, in the northern border
States, and southward on the Alleghanies, but most abundant in the
north through Canada, and westward to the Pacific in Washington and
Oregon, where, in the mountains, it often assumes the tree form,
growing to a hight of twenty-five to thirty feet, with a stem from
four to six inches in diameter. The wood is light, soft, and very
white to the center. It also extends southward to central
California, but here it is only a small bush, this form having been
described under the name of _Corylus rostrata_, var. Californica, A.
de C. This species probably reaches its highest development in the
Cascade range, in northern Oregon. The same or a closely allied
species of the hazel extends far into northern Asia. There are no
improved varieties of either of our native species of the hazel in
cultivation.
EUROPEAN SPECIES OF CORYLUS.
[Illustration: FIG. 39. CONSTANTINOPLE HAZEL.]
CORYLUS AVELLANA (Linn.). Common hazelnut.--Leaves roundish,
heart-shaped, pointed, coarsely and unevenly serrate; husk
bell-shaped, spreading, with a fringed or deeply cut margin. The
original form of this nut is supposed to have been ovate or oval,
but with a plant indigenous to such a wide range of climate and
country, and one that has been so long under cultivation,--running
wild in many localities where it is not a native,--it would be very
difficult at this time to determine its primary botanical
characters. A common shrub or small tree throughout the greater part
of Europe and Asia.
CORYLUS COLURNA (Linn.).--Constantinople hazel. Leaves roundish
ovate, heart-shaped; husk double, the inner one divided into three
deeply cleft divisions, the outer with many long, slender, curved
segments, giving to the calyx or husk a fringed appearance, but
leaving the end of the nut fully exposed (Fig. 39). Nuts small, and
for this reason rarely cultivated. Native of Asia Minor, where the
tree attains a hight of from fifty to sixty feet. It is, however,
hardy in France and England, and was introduced into the latter
country some three hundred years ago, probably by Clusius, who
received either nuts or plants from Constantinople, hence its
present name.
There are several other hazels and filberts, so distinct from the
two common European types that botanists have, in a few instances,
been inclined to elevate them to the rank of species, and among
these I may name _Corylus heterophylla_, or various-leaved filbert,
from eastern Asia, also the _Corylus ferox_, or spiny filbert, which
has a long and deeply cut or fringed husk. It is a native of the
Sheopur mountain in Nepaul. But from the two common European
species, _C. Avellana_ and _C. Colurna_, and their hybrids, many
hundreds of varieties have been raised, and from among these we may
readily select a dozen possessing all the distinct and estimable
properties to be found in this genus of nut-bearing plants; to
multiply names without securing anything of intrinsic value, is but
a waste of time and labor on the part of the cultivator.
As we have no popular varieties of American origin, I am compelled
to consult European catalogues in making a selection of those most
promising for cultivation here, and this is, perhaps, an advantage,
inasmuch as our transatlantic cousins have had a long experience and
abundant opportunities for determining the merits of the varieties
they recommend. If hardiness and adaptation to our soil and climate
are to be taken into account, in making a selection, then we may
fail for the want of experienced guides, as it is undeniable that
very few persons in this country have ever attempted to conduct
extended experiments in the cultivation of either the native or
European species and varieties of the hazel.
Taking this view of the situation, I shall avail myself of the small
but select list of varieties given in that standard work, "The
Dictionary of Gardening," edited by Mr. George Nicholson, of the
Royal Gardens, Kew, England.
SELECT LIST OF VARIETIES.
ALBA, OR WHITE FILBERT.--Considered in England one of the best
varieties in cultivation. From the peculiar structure of the husk,
which contracts rather than opens at the outer edge, this filbert
can be kept longer in its cover than most others. As fashion demands
that fresh filberts must be brought to the table in their husks,
this variety deserves special attention. It is also known as
Avelinier Blanche, Wrotham Park, etc.
COSFORD, OR MISS YOUNG'S THIN-SHELLED.--Nut oblong, of excellent
quality; husk hairy, deeply cut, about as long as the nut. Highly
valued on account of the thinness of the shell.
CRISPA, OR FRIZZLED FILBERT.--Shell thin, somewhat flattened; husk
richly and curiously frizzled throughout, open wide at the mouth,
and hanging about as long again as the nut. Ripens late, and one of
the most productive.
DOWNTON LARGE SQUARE.--Nut very large; shell thick and well-filled;
husk smooth, shorter than the nut. A peculiarly formed semi-square
nut, of the best quality.
LAMBERT'S FILBERT (_Corylus tubulosa_).--Nut large, oblong; shell
thick and strong, the kernel being covered with a red skin; husk
long, rather smooth, serrated at the edges, longer than the nut. A
fine, strong-growing, free-fruiting variety. It is quite popular in
California, where it has been in cultivation for twenty years or
more under the name of Red Aveline. Specimens I have received from
there were not as large as those raised in England, but this can be
accounted for by the difference in climate. This variety is
cultivated in Europe under various local names, as, for instance,
Great Cob, Kentish Cob, Filbert Cob, and Large Bond Cob.
GRANDIS, OR ROUND COB-NUT.--Nut large, short, slightly compressed,
very thick and hard; husk shorter than the fruit, much frizzled and
hairy. This is supposed to be the true Barcelona nut of commerce,
and is one of the finest grown. This is the large round hazel or
filbert so largely imported for the trade in this country. It has
many synonyms, and among them we may record Downton, Dwarf Prolific,
Great Cob and Round Cob.
PURPLE-LEAVED FILBERT.--Usually cultivated as an ornamental shrub in
this country, but under proper treatment it is one of the most
valuable for its fruit. Leaves very large, and of a deep purple
color. Nuts and husk of the same color, which they retain until cut
by frosts. Nuts large, an inch in length; husks much longer than the
nut, and slightly hairy. The catkins are tender and become
winterkilled in our Northern States, but if the pistillate flowers
are fertilized by pollen from some more hardy plant, this
purple-leaved filbert is exceedingly prolific. I have gathered
eighty nuts from a small bush in my garden, the flowers of which had
been fertilized from another variety in early spring.
RED FILBERT. Red Hazel, Avelinier Rouge.--Nut medium ovate, not long
as in the _tubulosa_, or Lambert's filbert; shell thick; husk long
and hispid. A very productive variety of good quality.
SPANISH FILBERT.--Nut very large, oblong; shell thick; husk smooth,
longer than the nut. A very large variety, sometimes confounded with
the Round cob-nut and its synonyms.
PERSONAL EXPERIENCE WITH FILBERTS.
Believing that our failures are often of far more value, in the line
of education, than our successes, I shall not hesitate to place my
own on record as guideposts to those who may be seeking the most
direct road to success in nut culture. Having had a rather extended
and expensive experience in the cultivation of filberts, I propose
giving a brief account of it here, with the hope that it may save
some other enthusiast from losing time and money.
My attention was first specially drawn to these nuts in 1858,--while
a resident of the city of Brooklyn, N. Y.,--by a neighbor who had a
moderately large garden, on three sides of which he had planted a
row of English filberts. These trees, at the time, had attained a
hight of about fifteen feet, with broad, open heads, and they rarely
failed to produce a heavy crop of nuts, which sold readily at very
remunerative prices, for as they were always gathered in the husks
and sold by the pound, the amount obtained from these few trees
seemed to be enormous, considering the small space they occupied in
this garden. The owner of these filbert trees, being an Englishman
by birth, never tired of showing his English filberts to visitors,
and of descanting upon their value, as well as upon the stupid
indifference of the Yankees in neglecting the cultivation of these
valuable nuts. I imbibed enough of my neighbor's enthusiasm to
secure a good stock of his plants, a few years later, for
cultivation in my grounds here. The third year after planting, quite
a number of the bushes produced a fair crop of nuts, but I noticed
that an occasional shoot was affected with blight, and these were
immediately cut out and burned. The next season more of the branches
were affected, and from these the blight extended downward on the
main stems, and when these were cut away the sprouts from below made
a very vigorous and apparently healthy growth, some reaching a hight
of six feet the first season, but a year or two later these were
also attacked and destroyed by blight.
Finding that the filberts in my grounds were doomed, I visited my
old neighbor in Brooklyn, hoping to learn something of the origin or
cause of the disease; but the blight had invaded his garden, and not
a tree remained. On my return from this visit I had every filbert
and hazel plant on my place dug up and burned, thinking by such
means to stamp out the disease. After waiting ten years, I thought
it time to try filberts again, and to be certain of securing pure
and healthy plants, I concluded to raise them from the nuts, and
sent an order for a few pounds of the largest and best variety to be
found in the celebrated filbert orchards of Kent, Eng. In due time
the nuts arrived, and they were very large, and all of one variety,
as ordered. They were mixed with sand and buried in the garden until
the following spring, then sown thinly in shallow drills and covered
with about two inches of rich soil.
[Illustration: FIG. 40. ENGLISH FILBERT ORCHARD, FIVE YEARS FROM
SEED.]
[Illustration: FIG. 42. EXTRA LARGE HAZEL SEEDLING OR ROUND ENGLISH
FILBERT.]
[Illustration: FIG. 41. VARIETIES OF FILBERTS AND HAZEL SEEDLINGS.]
At the close of the first season the plants were from one to two
feet high and quite stocky, with a mass of small fibrous roots. The
next spring they were transplanted into nursery rows, and set about
one foot apart. The third spring I laid out about one acre for a
specimen filbert orchard, and after the ground had been thoroughly
prepared, the plants were set ten feet apart in the row, and twelve
between the rows. No crop was planted among the trees, but the
ground was kept clean and free from weeds during the summer, with
cultivator and harrow. All suckers springing from the base of the
stems were removed as soon as they appeared, and under such
treatment the plants made a vigorous growth. Two years later quite a
number of the trees came into bearing, these showing that I was
likely to have nearly as many varieties in my orchard as there were
trees. Some of the varieties might be better than the parent, but
the greater part were certain to be inferior in size. The fourth
year after planting in the orchard the trees gave me a heavy crop of
nuts, and they made a fine appearance as one looked down between the
long rows, as shown in Fig. 40. But this season my old enemy, the
filbert blight, appeared again, and branches and main stems began to
blacken and the leaves to wither. But I had bushels of nuts and in
great variety, and by sending specimen baskets of the long-husk
varieties to dealers in New York, learned that there was an almost
unlimited demand for such nuts, at prices ranging from thirty to
seventy-five cents per pound, if sent to market in their fresh,
half-ripened husk; but later on, when the nuts have fallen out and
become thoroughly ripened, as when imported, ten cents a pound may
be considered an average price for the larger varieties. Several of
these are shown in Fig. 41, of natural size and form. Another
extra-large hazel is shown in Fig. 42. The fifth year after
planting, my specimen filbert orchard had suffered so much from
blight that it appeared as shown in Fig. 43; but a few dozen trees
have been reserved, the rest being removed and reduced to ashes.
[Illustration: FIG. 43. FILBERT ORCHARD STRUCK WITH BLIGHT, FIFTH
YEAR FROM SEED.]
=Name and Nature of the Filbert Blight.=--The reader must not
suppose that one who has spent as much time and money as the writer
in experimenting with these nuts, would make no effort to discover
the origin and name of such a virulent disease, and means of
destroying it if these were known. For many years I had been well
aware of its presence in nearly all of the nurseries of the older
States, as well as in the public parks and private gardens. In the
meantime I had diligently examined the reports of the Division of
Vegetable Pathology of the U. S. Department of Agriculture, as well
as the hundreds of bulletins of the various State experiment
stations, treating of the fungous diseases of plants, all without
finding a hint or reference to this widely distributed and
destructive blight of the filbert. I also sent many specimens of the
diseased twigs and branches to professional mycologists, with no
better results. With the nature of the disease, its mode of
multiplication and distribution, I had become somewhat familiar, but
the information sought was: Had it ever been described and given a
scientific name, and if so, where, and by whom? This much of its
history had somehow escaped me, and, as it would appear from the
following correspondence, the chances were none too good of finding
it.
In reply to an inquiry directed to the U. S. Department of
Agriculture, Division of Vegetable Pathology, I received the
following:
WASHINGTON, D. C., Aug. 4, 1894.
DEAR SIR:
Your letter of Aug. 2, relating to the disease of the filbert,
is at hand. In reply I have to say that we have not investigated
this trouble, and are therefore unable to furnish you with any
definite information upon it. Specimens of the disease, as you
describe it, have never been, so far as I know, referred to the
Division, nor am I able to find any record of any such disease
in foreign or domestic literature. If you will send us specimens
we shall be pleased to examine them and furnish you a report. We
should also be pleased to have any information from you in
regard to the manner in which the disease works. Very truly,
B. T. GALLOWAY, _Chief of Division_.
The specimens requested were forwarded promptly by mail, and in the
absence of the Chief of Division, they fell into the hands of one of
his assistants, who reported as follows:
DEAR SIR:
Your letter of Aug. 7 is received, together with the specimens.
The stems of the _Corylus_ are affected with one of the
Pyrenomycetes. _Cryptospora anomala_, Pk. The fungus is
described in "North American Pyrenomycetes," by Ellis and
Everhart, p. 531. It attacks _Corylus Americana_, but appears to
be worst on the European varieties, as you say. The pustules
appear first on the young branches, and later on the older ones
and on the trunk. The roots are not killed.
The only remedy known is to cut out and burn the diseased stems.
Whether Bordeaux mixture or any other copper solution will
protect the shrub from attack, is not known. So far as I know,
it has not been tried. It is probable, however, that if the
stems were thoroughly sprayed with the Bordeaux mixture they
would be protected from attack. The mycelium of the fungus grows
into the cambium and practically girdles the stems. The black
pustules contain the spores.
Very truly yours,
ALBERT F. WOODS, _Acting Chief_.
On the receipt of this note of Prof. Woods, I looked up Ellis and
Everhart's work, a voluminous one of over 800 octavo pages,
published by the authors at Newfield, N. J. This filbert blight is
briefly described under the scientific name of _Cryptospora
anomala_, Pk., but Prof. Peck writes me that "the description was
made from specimens discovered near Albany, N. Y., in May, 1874. In
1882 this description was republished by Saccardo, in his "Syllage
Fungorum," Vol. I, p. 470, under the name of _Cryptosporella
anomala_. The original name in Report 28, p. 72, was _Diatrype
anomala_. In 1892 Ellis and Everhart, in "Pyrenomycetes of North
America," p. 531, changed the name again, making it _Cryptospora
anomala_." So at present we have the names of this fungus in the
following order:
_Diatrypes anomal_, Peck, 1876.
_Cryptosporella anomala_, Sacc., 1882.
_Cryptospora anomala_, E. and E., 1892.
Ellis and Everhart, after giving scientific description, add,
"On living stems of _Corylus Americana_, Albany, N. Y. (Peck),
Iowa (Holoway), on _Corylus Avellana_, Newfield, N. J. The
pustules appear first on the smaller branches, and are serrately
arranged along one side of the branch; afterwards they appear
also on the larger branches and on the trunk itself, and in the
course of two or three years the part of tree above ground is
entirely killed. The roots, however, still retain their
vitality, and continue to send up each year a luxuriant growth
of new shoots, destined to be destroyed the succeeding year by
the inexorable pest. The imported trees seem to be more
injuriously affected than the native species."
The observations of Ellis and Everhart and Prof. Woods accord with
my own, but I may say that the infested branches often show the
presence of the mycelium in the bark and alburnum,--by a slight
shrinking,--weeks or months before the pustules appear, for these
are merely indications of the last stage in the life of the fungus,
and with the throwing off the spores from these pustules the old
parasite perishes.
The pustules, when fully open, are from one-sixteenth to one-eighth
of an inch in diameter, usually round, but sometimes slightly oval
in form, and placed mainly in almost straight rows lengthways of the
branch, as shown in Fig. 44. These pustules appear on wood of all
ages, from two years upward, and in what may be termed patches,
ranging from a few inches to a foot or more in length, and more
frequently on the upper side than the underside of the branches.
[Illustration: FIG. 44. HAZEL FUNGUS.]
This fungus is undoubtedly indigenous, and its host plant is the
common American hazel (_C. Americana_). From a very careful search,
I have not been able to find any clump of these bushes of any
considerable size that was entirely free from pustulous stems. But
on these wild plants it seems to do but little harm, for if a stem
is killed, another soon springs up from the roots to take its place;
but when this fungus invades our orchards and gardens and attacks
filbert trees, we recognize it as an implacable enemy. How far the
spores of this fungus are likely to be carried by the wind,
transported on the clothes of a person, or the hair of domestic
animals, I do not know, but it certainly is not safe to plant the
susceptible species and varieties within a mile of the wild hazel
bushes, unless the planter is prepared to use fungicides freely on
his trees. There are certain phases of this filbert blight that are
rather obscure and scarcely explainable; as, for instance, its
virulence among some species and varieties, and almost if not total
absence among others. So far as my observation extends, I have never
found it attacking the native beaked hazel (_Corylus rostrata_), and
my correspondents in the Northwest and in the Pacific States assure
me that no blight on the hazel has, as yet, been found there, and
its absence is probably due to the fact that the common hazel (_C.
Americana_) is not an inhabitant of these regions.
In a neighbor's garden just across the highway from my own, there
are, at this time, four old European hazelnut trees, fully twenty
feet high and as many years old. They are of two varieties: one a
small round nut, the other a long, slender nut, but neither of much
value, because of their small size. The trees, however, are
perfectly healthy, never having suffered from the blight, although
these four are all that remain of a long row of choice European
varieties all planted at the same time. Blight destroyed the better
varieties, while these inferior ones continue to thrive and are
exceedingly productive.
This native fungus that causes blight in the hazels is but one of a
large number of similar maladies which have appeared and often
worsted the horticulturist, in his endeavor to introduce and
cultivate foreign species and varieties of plants, and like the
tropical fevers, they may pass unnoticed among the natives, but are
terribly fatal to immigrants from cooler climates. The disease so
well known as the black knot (_Otthia morbosa_, Schu.), and widely
destructive to the European varieties of the plum, and Morello
cherries, has existed for ages among our native plums and black
cherries, doing comparatively little harm; but it seems to protest,
by its virulence, against the introduction of some foreign species.
The same is true with various blights and rusts which attack the
exotic pear, apple, quince, peach, and other of the larger fruits,
and we have only to ascend the scale a few degrees from the
microscopic fungi to the microscopic insects, to meet on the very
threshold of this realm the minute but unconquerable grape louse
(_Phylloxera vastatrix_), which for more than two centuries has
prevented the successful cultivation of the European varieties of
the grape in the open air everywhere east of the Rocky mountains in
North America; although this minute insect has ever been present and
a constant parasite of the indigenous species of the grape, but
scarcely affecting the health of its host. The plum curculio,
chestnut and hickory weevils, bean weevil, and many other similar
species of insects appear to be ever protesting against the
introduction of exotic plants, as well as the improvement of our
indigenous kinds.
It is this blight, and nothing else, that has prevented the
extensive cultivation of the improved varieties of the European
filbert and hazelnut in this country, and not the uncongenial soil
and climate, as has been so often "officially" proclaimed by men
whose theories are far greater than their practical knowledge of
such subjects. Men whose experience with these nuts has been limited
to a few isolated bushes or trees in gardens or nurseries, where
they were protected, or beyond the reach of the spores of the blight
fungus, as has already been noted in the experience of Prince,
Downing, Barry, and my neighbor Butler, of Brooklyn, could scarcely
understand why others should remain so indifferent to such a
promising industry, or why the demand for the trees remained so
limited, with scarcely an attempt to plant filbert orchards anywhere
in this country. Nurserymen have continued to offer the choice
varieties at low prices per plant, and to advise their customers to
cultivate filberts extensively, even to setting them in hedgerows;
and yet home-grown filberts remain as rare in our markets as they
were a hundred years ago, and all due to the simple reason that the
insidious filbert blight still scatters its spores unrestrained.
With the present almost universal employment of various fungicides
for the destruction of blights, mildews and rusts on cultivated
fruits and vegetables, we may confidently assert that the diseases
of the filbert may be readily controlled by the same means. The
spraying of the trees with Bordeaux mixture and other copper
solutions will certainly destroy the fungus spores, and with these
out of the way filbert culture may become of as much importance and
as popular here as it is in certain countries of Europe. In my own
experience I have found no other nut tree (barring always the
blight) that has been more satisfactory. The plants come forward
rapidly, fruiting freely and abundantly when young, and if properly
trained, the crop can be gathered with little labor, and as it is
ready for use a month or more in advance of the arrival of fresh
nuts from abroad, the home market during the time is at our command.
The number of applications of the fungicides that will be necessary
during the season to rid the trees of blight, or the strength of the
copper solution used, will depend somewhat upon circumstances and
the condition of the subjects operated upon. If the trees are
growing near hedges of wild hazels, where there is a constant or
annual influx of the fungus spores, then greater care will be
required to suppress them than if the trees are some distance from
such sources of contagion; and it may be well for those
contemplating planting filbert orchards, to examine their
surroundings carefully in advance, in order to avoid local
blight-breeding plants, and have these destroyed if any are found. I
would also warn the cultivator against collecting branches of the
wild hazel in the spring, carrying pollen-bearing catkins to be
employed in fertilizing the pistillate flowers of the cultivated
varieties, for by such means blight spores may be readily introduced
into orchard and garden.
It will seldom be necessary to practice artificial fertilization,
where any considerable number of trees are grown near together,
because if ninety per cent. of the male catkins are winterkilled,
the few remaining will be sufficient to supply pollen for the
pistillate flowers. In my grounds filberts have never failed to
produce annual crops after reaching a bearing age, although they
have been subjected to great extremes of temperature in winter. One
year the trees were in full bloom the last week in February, and
although cold weather followed, the protected pistillate flowers
were not injured. The winters of 1894 and 1895 were among the
severest, in the way of continuous low temperature, I have ever
experienced here, and while the filberts did not bloom until the
first week in April, the crop proved to be abundant.
=Insects Injurious to Filberts.=--My personal observations lead me
to believe that the filberts and hazels are, in this country,
remarkably free from the depredations of noxious insects. Two
species of nut weevils have been reported as breeding in the wild
hazelnuts, viz., _Balaninus obtusus_, and _B. nasicus_, but among
the many bushels of the European varieties of the filbert produced
in my grounds I have never found one infested by a weevil or other
insect. In Europe a nut weevil (_B. nucum_) is said to be very
destructive to the wild hazel, often invading the filbert orchards,
and this we can readily believe, because they are not at all
uncommon in the imported nuts, but fortunately have not, as yet,
become naturalized in this country.
The great hazel-leaf beetle, or as more generally known, elm-leaf
beetle (_Monocesta coryli_), has been known in a few instances to
attack and defoliate large patches of the wild hazel bushes, but
this insect seems to prefer the elm, hence is rarely found on the
hazels. But should it ever invade our filbert orchards, it can be
readily destroyed by dusting or spraying the trees with Paris green,
London purple, or other well-known insecticides. There may be an
occasional invasion of caterpillars, like the tent worms, spanworms,
leaf rollers of various species, and what are called leaf miners,
but as these infest almost all kinds of deciduous trees and shrubs,
we cannot consider them specially injurious to the filberts and
hazels.