The San Francisco call., 1905-08-14
Red Leaf" Disease
IS Dangerous
MaIady.
Professor lWight
Makes Valuable
Report

BERKELEY. Aug. I3-The mysterious
red leaf disease" aieh was first OBJ
served in the vineyards of Sonoma Coun-
~ two years ago. and which was at
once given attention by the viticultural
experts at the State University, forms
the subject OF q bulletin, issued by the
Agricultural Department of the universe
ty, the author being Ormond Butler. lie
was delegated to investigate the disease
By Professor E. II. Twlghe.
r Professor Twight gives a valuable eA-
PLANTATION of the investigation which Mr..
Butler was authorized TO undertake, as
follows:
In 1903 the viticultural department OF the
College OF Agriculture OF the University oi
for a few seasons. had beer observed in SO
noma County and was beginning 10 cause some
speetion Of the vineyards OF Sonoma County
from Santa Rosa 10 Cloverdale including tho =
Of Alexander Valley and Dry Greek we found
that the "red-lssf disease, as the maiaoy
was called, was sufficiently widespread TO re-
cuire special attention. The "red-leaf dis =
ease was al that time associated by many
persons with the Anaheim disease, and BY
some with snthracnose. The first theory was
set aside priori. on account OF the difference
in the effect the canes and grapes, and also
on account Of the lack OF viruence of the dis
ease when attacking the Mission vines The
suggestion that II might De anthrdcnoSe was
easily set aside. as the markings OF the dls-
ease on leaves. canes and berries are OF an en- :
tirely different character; it is very doubtful
that the trge anthracnose has ever been found
in q vineyard OF California.
On my return from this trip OF investigation
/ passed through Napa Valley to compare the
red leaf disease with a nlalady of similar
character that had caused damage in some
sections, and. after consultation with DR..
odic study Of the ''red-leaf disease and Nj.
Q. Butler was appointed to carry out the in
vestigations
During the same season arrangements we4e
made wi.h seyeral vineyardists to establish
experiment plats on their land during the fol-
While investigating the "red7leaf disease
Mr. Butler found that number of maladies,
either parasitic physiological. were respon-
of the vines. Among these affections phyIlox-
era. roct-rot. mildew. lack of affinity between
70 soil. mechanical injuries, erinose and
blsck-k knot are quite prevalent in Sonoma
County, as well in most vineyard districts
Mr. Buffers observations seem to show tina !
the cause Of the red-leaf disease is not para
site, but thst it IS probably due TO soil and
will be kept up during the coming season, and
q careful examination Of the subsoi and mos-
made through the growing season, so that def
mite conclusions may be drawn.
CONCLUDING THOUGHTS.
Mr.. Buffers conclusion, regarding the
cause Of the red leaf disease is as fol-
lows; 1T seems difficult to reconcile
facts with the development of leaf par
asfte. We are more inclined to believe
that the red-Ieaf disease is due TO the
same causes as the foEerage and the
rougeot, namely, a disturbance Of the
equilibrium between the absorption of wa
ter by the roots and its Transportation
by the leaves
In addition to the red leaf disease, Mr..
Butler treats, in his bulletin of the grape
shrivel and root-rot diseases. His re-
marks on the root-rot disease are under
stood TO be of unusual Importance just
now because the root-rot disease is do
ing q great deal of damage at this time
in parts of the Sacramento, San Joaquin
and Santa Clara valleys. In some dis
tricts the root-rot is far more destruct-
I've than the phylloxera
OF this root-rot disease Mr.. Butler says:
The root-rot is caused by fungus-possibly
several fungi-and in its usual form is very
within an infected area. The roots are soft,
watery, yellowish- brown in the entire woody
wFitish threa ds-the mycelium of the parasite
and gsxe of a strong nauseous fungous
odor. AS the lower roots are destroyed. and
the mortifcation enters the body OF the vine
and slowly eats its way in the trunk to the
surface Of the soil and even above, new
roots are sent out from the still healthy en-
come riddied with. and succumb to the at
tscks OF the fungus. In the last stages Of
the disease (that is. when the vine has sent
out few feeble canes about foot long) one
invariably finds near at the surface of the
soil. very free growth Of young tender
roots.
The root-rot is generally OF the form just
described. and takes from two 70 five years 70
kill the vine but IL may, in some rare cases
and IN young vineyards, spread with such ra-
pidity that IL kills the vines in eighteen
months and even in a single season.
The action Of this disease in its main char
acteristics is very similar to the malady
known among the French as the Pourridie, or
Blanc des racines and in Germany according
10 Mr. P. Viala, by the mama Of Weinstock-
fauie The areas Of depressed vegetation that
the phylioxera are Characteristic also of the
root-rot In each case there is a center of
affection though. when compared with the the
phylloxera the root-rot spreads more slowly
and appear circumscribed or local in its &C
ton. In the case of the root-rot there may
occur many small centers Of infection in close
proximity TO one another which may take sew
eral years to merge into one; whereas. in the
case of the phylloxera, when infection is so
general that several centers start very near
one another they rapidly become one.
vines aect@d tea win VI ours. n p saVed Vines
affected with the usual form are, when
treated before the disease has made much
progress amenable to treatment. The pre-
ventive treatment here recommended applies
equally well to both forms Of root-rot
The remedial or preventive measures used in
Combating the root-rot. or indeed any other
disease attacking the subterranean organs OF
plants are at best. but palliatives As the
! disease ts more general In soils with an i'm
perrneable substratum that are quite retent-
i've and miry after heavy rains, adequate drain
age is and will always remain the only valu-
! able preventive and curative measure. For
excessive humidity is the exciting cause OF
the disease: IL favors fungous development
and the tissues of the roots are soft, gorged
with water and IN condition to resist the
attacks OF parasites. An author CMr. P.
TIaIal who has studied the po1rride OF the
vine and fruit trees with particular care, says
lone must, TO prevent the disease from
spreading and rto protect ones self against 1t
lin new Plantations thoroughly drain the coils
IN which II existe and also those that are,
through their retentiveness, favorable to its
deveionruent Drainage is an excellent pre-
Ventive measure" he continues. and what Is
more the only efhcacious one. But as drain
age is not always economically possible, few
half measures that are al least useful may be
mentioned, even IL they have not the virtue
AS soon as the disease shows in the vine
ward an badly diseased vines Chat ie those
vines whose scant growth shows that their
main root-system is seriously attacked should
be removed.
SHALLOW SOIL FAVORED.
In soils that are subject to the root-rot,
roosed vines should always be planted. and az
should never be used. for they have to b.
nIsnted deeper than rooted vines the chances
OF Infection, especially the cut surface be-
ing thereby increased
Vineyards that have once been infected with
Ir~g "a oI~.-