Ellsworth American. [volume] (Ellsworth, Me.) 1855-current, 1913-05-14
COME DISEASES OF
THE POTATO.

,.4nn with reference 10 tue otnsr
P..o.growlng sections of the country.
~. ot ber states produce more potatoes,
-, with the exception OF possibly
,so. none have such large areas ex-
,I,,sIv devoted to this one crop.
W., her II be wheat, cotton or potatoes,
.Aa growing of one crop over large areas
The exclusion of others provides
,.,.bte conditions for the introduction
- .,,aad OF diseases. Geographically
"a commercially, Maine occupies the
..,s;,;on Of an outpost with reference to
ssrss, Of the country. Potato dieases are
-. I,tslv to be introduced into Maine
- canada, also from Europe, than is
,he case farther inland.
Maine is rapidly becoming great
...sto. seed garden for supplying states
s.,,hef south. This seed must be of the
s;ghss. quality and free from diseases II
,hs southern trade Is to be retained.
!, IA impossible to cover the whole sub
,.,, n rotate diseases In one lecture, so
- discussion will be limited largely TO
,,e more threatening diseases which are
.,rried by seed iubers, some OF which We
already have, and any of which we may
- csiisa upon TO contend with at any
time
The wart disease, or potato canker, Is
the most dangerous, potato disease which
49, oyer threatened this country. II II
shn,,d become established in Maine 1t
nigh, ruin the industry. IL principally
ATTACKS the tnber, which in severe cases is
changed into an irregular, rusty brown
.eoral-lgke mass. Slightly affected tnbers
are the most dangerous, as they are easily
ovsrlooked. The eyes OF such slightly
protrude in the form OF single or several
small nodules, and instead OF being white
or uurplish, as in normal tubers, will be
rusty brown.
The wart disease Is widespread and very
destructive In certain parts Of Europe,
and soils once infected retain the germs
far some years. The disease has not
reached the mainland OF North America
but short tina ago II was discovered in
Newfoundland
The corky or powdery scab is another
disease which has recently crossed the
Atlantic Within a fnw months we have
received specimens OF Il from an sdioin-
ing county in Canada, aud il may show
up In Maine at any time. This is caused
BY an entirely different organism than
ths, which causes our common potato
scsh, although the disease resembles the
latter. Unlike II, however, IL Is not
known to attack other plants. So far as
known, il IL spread entirely by infected
seed.
still another European disease has APP
peared In certain of the Western states,
and 1t may reach Maine at any time.
This is the leaf-roli disease. The plants
attacked appear unhealthy, usually of
decided yellow, but often the leaves have
sreddish or purplish tinge. prominent
Characteristic is a pronounced upward
rolling OF the leaves at the midrib.
Growth is checked and the formation OF
tubsrs is prevented, except occasionally
small ones at the surface or above ground,
but the plants may live nearly a. long IS
healthy ones. Plants attacked by leaf
roll resemble those affected with blackieg
or the Fusarium trouble, but they show
certain differences which readily distin-
guish them. This disease furnishes another
argument for care in seed selection.
The best German Psychologists have come
to the conclusion that 1t Is physiological
trouble, and Is associated with poor seed.
Potatoes from field where the disease APP
peared will, If planted, produce crop
more affected than the first.
Backlog, bacterial disease, which
causes a pronounced blackening of the
plant, as well as soft rot OF the tuber, is
widely distributed in Maine. This also
came to us from Europe. In some respects
1t Is carried by infected tubers, and is very
destructive in those States where our po-
tatoes are used for planting.
The purchasers OF Maine seed potatoes
are demanding that this disease be elimi-
mated. Since the bacteria which cause it
GO not live over winter In the soil In
Maine, We have been able to devise effee-
tive preventative measures. This consists
OF selecting for seed, tubers which are en-
tirely sound and perfect, and then disin-
ieeling them, with formaldehyde before
Planting. The method is fully described
IN bulletin le4 Of the Maine agricultural
experiment station.
The same method OF treatment that is
recommended for blackleg will do much
70 control scab, and will prevent its intro
onetion into uninfected soils.
Late blight, which is commonly called
sast', is also carried by seed tubers in
the form of rnt hnt az Ia u,sII knoWn IL
rapidly spreads from plant to plant in the
neid when 1t once gets started. The
enclency OF bordeaux mixture in the con-
tfoi OF late blight has been demonstrated
repeatedly. Where failure occurs, 1t is