Ellsworth American. [volume] (Ellsworth, Me.) 1855-current, 1916-09-27
NEW POTATO DISEASE.
Prematurs DEATH Of Potato Plants
Observed In Maine.

4
tion, in co-operstion with the plant
psychologists and the soil exrerts Of the
United States department OF agriculture,
has recently been giving considerable at
tention to . peculiar type Ct potato
trouble. This apparently Is new, or IL it
has occurred before in this State, it has
been largely overlooked. During the
| present summer it appeared rather sud-
denly in July and August in many parts
| OF Aroostook county, and cases have been
observed in, and specimens received from
| central and southern Maine. The federal
Psychologists have also reported . similar
| trou BILE Com other parts OF the country,
q tar south as Pennsylvania.
County Agent George n. Worden re-
ports that be has received many inquiries
| from Hancock county farmers regarding
this disease.
II 10 more commonly found on fields Of
Irish Cobblers, Bliss and Eureka, but it is
not entirely restricted to these early ma
turing varieties. 1t is also more likely TO
occur on early planted fields. What Is
more striking is the very apparent associ-
alton of the trouble with certain soil
types, or with those having q definite
type OF subsoii. TIE evidence 90 far OBJ
tanned In very suggestive that on such soils
the early death Of the plants is in some
way associated with q lack OF potash in the
fertilizer, or at least with an unbalanced
condition Of the fertilizer used.
In tais connection it may be mentioned
! that the st .tion published the results OF
some experiments made last year at
Aroostook farm, where potatoes were
grown with varying amounts of
potash and no potash This. was
high, weii-drained land belonging
to the better type OF Aeoostook potato
soil. Then the no potash plots yielded at
the rate Of ITO barrels of potatoes per acre,
while adjoining plots TO which the same
amounts Of nitrogen and phosphoric had
been applied, and to which 2, and 8
per cents OF potash were added, yielded at
the rate of ll6, lis and I'D barrels OF pota-
toes per acre respectively. This trouble
did not appear on the no potash plots on
that type OF soil on Aroostook farm in
1915, and, to date, has not been recorded
| this season.
| The first signs Of the diseased condition
under consideration appeared the latter
part OF July. 1t wss then noticed that
the foliage, instead Of being the normal,
healthy dark green, showed Q peculiar
bronziug and yellowing OF the leaves. As
the disease progressed, the affected plants
have very much the appearance OF pota-
toes jus. previous TO maturing. In the
a
the entire plant il wtited.
Frequently the diseased plants show
discoiored areas on various parts OF tn
surfaces OF the stems. Generally, but
not universally associated with the above
described conditions, the main stalk il
found to ne discoiored and hollow at the
point where it energies from the soil.
the following. Gross sections OF the
stems also sometimes SHOW q discoioration
and bIackcning OF the water and food
conducting vessels. Associated with the
discoioration and following OF the stems
are found numerous fungi At present II
cannot he stated definitely whether these
are parasitic and are concerned in thu
cause of the trouble oe ars only second
ary. bat ~ork i now in progress to de-
termine this point.
Observations tAas Tar uas1e BY the snii
experts and the pstheic9isss sho~ that
the trouble originates in tine swales or
low lands, where the natural drainage 10
mot 20 good - that on the higher ridge
lands. However, in . number OF cases,
the diseased condition under consider-
alton spreads gradually, but in not 20
severe type, TO higher ground.
| Soils which originally supported .
growth Of soft woods, or 1mixsd growth
land" develop the diseased condition in
its most severe type, while the ''hard
wood ridges" show 1t least, or not at all.
The surface soil where the first mentioned
wood growth occurs 10 generally dark
| gray to black in color, beneath which 10 Q
dull yellow or gray notified suhsoil, an
indicstion Of sluggish or poor drainage.
Upon ths higher ridges, where the drain-
I age il good, the surface soil il more often
brown to yeliowish- brown in color, with
bright yellow OF dark yellow subsoil.
These remarks relative to soil types are
based upon observations made in Aroos-
took county by the soil experts Of the
United States department Of agriculture.
Detailed cooperative studies relative to
the fundamental factors associated with
the cause and control OF this diseased
condition have been planned and are now
being carried ON by the department and
station specialists. Among other thing
an earnest effort will b made to deter
mine whether the disease 10 of . parasitic
nature and can b transmitted with the
need tubers, and whether its occurrence on
field one year will exercise detrimentai
effect upon . potato crop planted on the
same land the next year.
| The natural diflsrentiations in the soils
on Affected fields are being studied, and
\ samples collected for laboratory inyesti-