The Greeley tribune., 1907-07-25
SOME ADVICE
THE POTATO SITUATION IN
THE GREELEY DISTRICT
Prof. E. R. Bennett of Agricul-
tural College Tells of Troub-
les with Beetles and
Fungi

The prospect for record crop Of
potatoes in the Greeley district this
year is not very encouraging. The
potatoes. worst insect enemy of this
locality, tile little black flea beetle,
has been particularly destructive so
far this season. Their numbers for
some reason, probably owing to the
light winter, are much greater than
usual. The cold backward season
has caused the insects to appear
later than usual, so that where they
are usually mostly gone by the time
the plants come through the
ground, this season in most fields the
plants we're up about the time the
beetles appeared, so that the maxi.
mum of damage from them has re-
suited. These insects at this time
of year live by eating the foliage Of
potato, tomato and other closely re-
lated plants. They do not eat the
stem of the plant OF at the surface
of the ground as is so frequently
stated by growers. The damage from
this brood of the insects comes SIM
ply from the reducing Of the leaf
surface by the insects eating holes in
the leaves.
Very soon now the beetles will
lay eggs on the under ground stems,
or new tubers, that are forming and
the resulting larvae will feed upon
them, causing the pimpley appear
ance THAT was SO noticeable on nearly
all the potatoes of last season.
The time has passed for any REM
edy. II we had known that the in
sects we're coming In such numbers
bordeaux mixture and an arsenite
might have been sprayed on the
vines. This remedy kills some Of
the insects but helps more as pre-
ventive. The insects do not like
the material and will move on to
more congenial surroundings.
The serious trouble with the po-
tato fields, however. is not due so
much to insect attack as to the rot
ting of seed tubers In the ground
II the weak, sickly plants be dug the
seed tuber will be found decayed.
This decay begins on the out surface
and eats its way through to the
skin. Those tubers that were at
tackled when first planted did not
sprout at all: others sprouted but
were cut off before sufficient roots
we're developed to support the plant.
In many cases the disease has fol-
lowed from the old seed tuber up the
stem of the plant and destroyed 1t
even after the plant has grown sew
eral inches above ground. Some
fields are so badly affected from this
trouble that they are being plowed
up and sown to grain crops. In
others the loss is from ten to fifty
per cent.
Microscopical inspection of these
diseased tubers and plants shows the
presence of one of the many species
of fusarium. This is undoubtedly
the same fungus that has caused the
drv rot of potatoes in the dugouts.
Two or three peculiar things about
the attack of this disease are notice
able. First, fields that grew pota-
toes last year are much more affected
than alfalfa land. This can be ex-
pIained from the fact that the crop
last year was damaged by this fungus
as well as by rhizoctonia. The
fusarium fungi are ordinarily sapro-
phitic. so easily lived over winter In
the decaying potato tops and other
vegetation
Second, soft seed and the green
seed from the mountains seem to be
affected more than home grown or
eastern seed. This is probably ow-
ing to the lessened power of resist
ance of the immature seed.
Third, whole seed, so far as our
observation goes, are not affected by
the disease at all.
Ii is too early in the season to
predict what the outcome OF this at
tack will be, but from our observa-
tions we may safely draw some con-
c,usions. II this disease persists 1t
will hardly pay to plant potatoes
two successive years on the same
land. 1t may be necessary to follow
the plan suggested by some people,
koko Drnt,-