Shenandoah herald. [volume] (Woodstock, Va.) 1865-1974, 1917-02-02
NEW POTATO DISEASE.

certain soils and apparently as
ISOLATED with the lack of potash
in the commercial fertilizers used
was prevalent last summer in
various sections of the East. Ac-
cording to specialists of the Bu-
reau of Plant Industry, United
States Department of Agricul.l
ture, the trouble was largely con-
trolled by the use of stable ma
nure. The disease may be ex-l
pected to appear again with i'm
creased severity during the COM
ing season in many potato-grow-
ing sections, from Maine to Vir-l
ginia, and probably also farther
outh. It was first noted in scat
tered fields in 1915. It 1916 it
became serious and general over
considerable areas. Last year
the disease was first observed
late in June in Maryland and
Virginia, and during the latter
part of July in Maine. The af-
fected plants first develop a down
ward rolling of the leaf margins,
accompanied by a peculiar bronx
ing of the surface, sometimes
mistaken for spray injury. Since
it occurs on unsprayed as we'll as
on sprayed plants, it can not be
due to the corrosive action of
sprays. The foliage gradually
turns brown--not yellow--and the
plants ripen prematurely. Death
of the leaves and sudden collapse
of the stems at the ground leve!
follow. The yield. of course, is
much reduced.
The disease is found more COM
monty on fields OF early-maturimg
varieties, but is not restricted to
them. 1t also appears first on
early planted fields.
What is more striking is the
very apparent association of the
trouble with certain soil types,
at least in Maine, where this re.
lation, as well as other features
of the trouble, are being investi.
gated by the department experts
in cooperation with the Maine
Agricultural Experiment Station
Soils which originally support.
ed the growth of soft woods, OF
mixed-growth lands" develop.
ed the diseased condition in its
most severe type, while the hard.
wood ridges showed it least OF
not at all. The trouble appeared
first in the swales or lowlands,
where the natural drainage was
not so good as on the higher
ridge land. When the disease
appeared at all on the higher
ground, it was of a less severe
type.
Specific fungi are frequently
found on the stems of the COL
lapsing plants, and some of these
most constantly seen belong to
disease-producing groups. Their
relation to the trouble is being
Investigated, but the present In
dications suggest that they are
not the primary cause but have
attacked the plants already seri-
ously weakened by other agen-
cies.
Fertilizer experiments in prog
ress on affected fields demon
strated that the plots receiving
potash showed little or no signs
of the trouble, even where the
other plots were entirely dead
Stable manure also held the
disease in almost complete con-
troll.
Investigations of the trouble
by the department are incom-
plete, but the present indications
are that it is due to insufficient
potash. or, perhaps, in some soils
ut least, to an excess of nitrates
In the presence of a minimum
potash supply. Farmers who are
unable to secure potash fertilizer
for their potato fields but who
have stable manure may insure
their crops against attack by It's
use. In sections where certain
types of soil have been observed
to suffer from the disease under
discussion, and it is advis a Bile to |
plant potatoes on these types
next year, it is strongly recon.
mended that potash fertilizers or
stable manure be applied if either
are obtainable.
Fer . Bl1lous Attack
When you have . severe headache. ,
accompanied BY coated tongue,