The Portland daily press., 1883-02-13
The Potato Rot.

At the late meeting of the Maine Pomo-
logical Society, Prof. G. 81. Fernald of the
State College read paper on the potat
rot. He began by saying that the potato
disease known as the "rot," had been more
destructive to this important crop, than all
other causes combined. 1t appeared in
Belgium in 1912, in Canada in 1874, and in
the United States in 1916. 1t destroyed the
crop in Ireland, causing the death by starva
tien of more than million people. There
were many theories propounded as to the
cause OF the disease. Some thought it to be
the work of an insect, but what kind of an
insect no one could tell. One theory was
that it was visitation of Providence by
which the sins of the people were to be pun
ished. Finally scieuce was appealed to, and
investigation showed that diseased potatoes
were affected with an unmistakable fungi.
1t was denied by many for long time, that
the fungi caused the rot of the tuber, but
this point Is now generally conceded.
The Professor, from diagrams, showed a
cross section of potato leaf, showing its
internal structure, and pointed out the func-
tions of its various parts. The zoospores
enter the leaf al the stomota or mouths of
the leaf, and when once inside, take up the
nutriment designed for the development of
the plant, and thus destroy it. Some idea of
their number may be inferred from the fact
budJ 9udIt luCl Vi 40dl ludy COutdlA tllico
million spores; of course with such an in
Vulnerable mass of parasites, the whole top is
soon destroyed. As the tops dry and crum-
BILE, these spores are takeen up by the wind
and carried from field to field and from
farm to farm, spreading the devastation far
and wide. The season of the potato is short,
and the question may be asked, what be-
comes of these zoospores or fungi during the
remainder of the year? Botanists were for
lOpr 4irnn eoarahira For fhaip roefinO
places during the winter, for until this could
be ascertained, they could not propose a
remedy. 1t was thought for time that
they entered the clover plant, and some
they did, they would not use the manure
made from it, thinking that the fungi would
retain their vitality after passing through
the alimentary canal of the animal. 1t is
now known that the spores after the death
of the plant, find their way into the earth,
where they remain through the winter.
They may also attack the tuber and destroy
it, the same as they do the tops. In the
spring they develope III the warm, moist
earth, and are prepared to renew their work
of destruction the following year.
Investigators kept many of these spores
over during the winter; those that were kept
dry did not germinate, but died, while those
that were kept in moisture, generally lived,
thus giving an idea of the conditions under
which they will be perpetuated in the soil.
The lecturer pointed out various ways in
which the fungi reproduce their kind The
spores are broken off and waited from field
to field.
heremedy is to pull the infested tops and
burn them at once; this is the main depend
ence for destroying them. Potatoes should
be planted on dry or well drained land,
where the best conditions for the develop
ment of the fungi are wanting. Warm, rainy
weather in late simmer is faVorahla tn their