The diamond drill. (Crystal Falls, Iron County, Mich.) 1887-1996, 1917-02-03
NEW POTATO DISEASE.
Prevalent Last Season In Eastern Sec
tiOns-ApplIcation OF Potash or
Manure to Soil Recommended.

A potato disease appearing on GER
tain soils and apparently associated
with the lack OF potash in the CONNER
cial fertilizers used was prevalent last
aummer in various sections OF the
East According TO specialists OF the
Bureau OF Plant Industry, United
States Department of Agriculture, the
trouble was largely controlled by the
use OF stable manure. The disease
may DO expected TO appear again with
increased severity during the coming
season in many potato-growing sec
tons. from Maine to Virginia, and
probably also farther south II was |
hrst noted in scattered fields in 1915 |
In 1916 il became serious and general
over considerable areas. Last year
the disease was first observed late IN
June ia Maryland aud Virginia and
during tic latter part q July in
Maine. The affected plants first de-
velop downward rolling q the leaf
marrins. accompanied by g peculiar
bronzing Of the surface sometimes
mistaken Tor spray injury, Since 4
occurs on unsprayed as we'll as on
SPRAYED plants, it cannot be do TO the
corrosive action Of sprays The foil
age gradually turns brown notyeliow
and the plants ripen prematurely.
Death OF the leaves aud sudden col
Iapee of the stems at the ground level
follow. The yield, Of course, T. much
reduced.
Tho disease 10 found more common
" on fields OF early-maturing varie-
, ties, but is not restricted to them IL
; also appears fret 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 relation, as well a.
. other features OF the trouble, are be-
ing investigated by the department ex-
ports IN cooperation with the Maine
Agricultural Experiment Station.
! soils which originally supported the
: growth OF soft woods, or mixed
i growth lands,9 developed the diseased
condition In its most severe type
|. while the hardwood ridges showed
least or not at all. The trouble ap
d peared FIRST in the swales or low
lands. where the natural drainage wa
"a not so good as on the higher ridg
r. land When the disease appeared
T. ali on the higher ground, II was OF
II less severe type.
ID Specific fungi are frequently foun
at on the stems OF the collapsing plants
Dc and some OF these most CONSTANT
I'd seen belong 10 disease-producin
( groups. Their relation TO the trouol
10 being Investigated. bu, the preser
OF indications suggest Tat they are nc
IN the primary cause but have attacke
be the plants already seriously weakene
~ by other agencies.
Fertilizer experiments IN pioBtes
ie on affected folds monstrated thu
~ the plots receiving ash showed u
s tie or no signs OF q trouble, eve
Il whore the other plas were entire
dead stable manure also held q
''u dlsea3e in almost complete control
Investigations OF the trouble by u
department are incomplete. but u
present indications are that Il Is az
10 insufficient potash, or, perhaps,
some soils at least, to an excess
J, nitrates in the presence Of minimu
potash supply. Farmers who are u
able 70 secure potash fertilizer I
their potato fields but who stable NJ
Ign nure may insure their crops again
ur- attack By its use. In sections whe
". certain types OF soil have been
IRA aoryod 10 suffer from the disease .
M der discussion, and II Is advisable
ras plant potatoes on these types ne
1--WE year. IL il strongly recommended u
ure potash fertilizers or stable manure
oiA applied II either are obtainabie.