The Fayette falcon. (Somerville, Tenn.) 190?-current, 1921-12-16
Sweet Potato Diseases and
Their Control
BY I. +. PECK.
Commissioner of Agriculture


The Mississippi State Plant Board in
1921 issued ruling that all the sweet
potato seed and slips destined .for the
growers of that State must be inspect
ed and shown to be free of disease. On
account of this ruling. Tennessee.
which is a heavy shipper of slips TO
Mississippi, made ispnections for the
first time, so as to permit our growers
TO continue business with that State
For some time it has been known
that diseases of sweet potatoes were
dling a great deal OF damage in this
State. Experiment stations in Ten
nessee and other states have worked
on this subject and have succeeded in
devislng measures that VIII control
these diseases, The chief trouble,
however, has been that the growers
have failed TO cope with the diseases
due to the lack of proper application of
prescribed control measures, particul.
arIy in the case of black rot. la ore
county in Tennessee, one third Of the
300, 900 busheI crep produced in 1920
was lost on account of black rot. This
was not the only county that suffered.
In order to prevent these heavy
losses on account of black rot, stem
rot foot rot AMI soft rot. the growers
must organize and make an active fight,
or they will be driven out of this field
of agriculture,
Black rot is probably the most com
mon and destructive of the different
field disea,es in Tennessee. 1t is
chafscterlzed by black and somewhat
sunken spots on the surface of the po,a-
to. email at first, but under favorable
conditions soon grow large and have
metallic lustre. The potato )es
whether raw or cooked, have bitter
taste. On the plant black rot begins as
a small black spot. which enlarges until
the entire shank rots. The .causative
organism of black rot is carried over in
the soil and brought in in diseased
manure, and on diseased slips. Spores
may also hibernate for long time in
the refuse in the storage house. When
clips or cutting are planted o. ground
which had crop OF infected potatoes
before, they are sure to cevelop olacl
rot Even washing .rsirs may carry
the disease from an Infected iield TO
one that is free. This il true of hot
beds placed on slope and used year
after year after black r, I has ,terec.
To control this disease Il IS ry es.
sentIsl TO have pe,f .ctly sound clean
potatoes. They should be examined ut
digging time and again cul ei just b.
fore bedding time. The seed should
then be dipped IN ss,lution of corrosive
sublimate, ole ounce to eight gallons
Of water, for five TO ten minutes. Dip
ping will do no good If the spore has
pierced the skin. The beds should be
cleaned out, the frames, sashes. and
other parts steriized with solution OF
blIestone "copper" sulphste). one pound
to twenty-five gallons of water. 1t is
also advisable to sterilize the soil in the
bottom of the bed with bluestone sou
tion in the proportion Of one gallon of
water to each cueic foot or Sal. Then
take fresh sand from the woods. about
five or six inches below the surface, and
use it to bed IN. A layer of fresh
clean dirt on top is used to atop baking.
Rich dirt Is unnecessary for bedding
purposes. Before planting the slips
sAould be examined to determine any
presence of disease on the shank or the
presence of wilt. These should then
be planted in field that has never
grown potatoes or else ore that has
rested three or four years.
Dry weather should be chosen for
digging before fros. and the potatoes
should then be stored 10 we'll construct:
ed potato houses which have been
thoroughly dislnfected and cleaned Of
oil refuse. This may be done by spray- =
ing heavily with blue stoue. one ounce
to twenty-five gallons Of water. All
cleaning and dislnfecting should be
done before potatoes are dug. II ,s
wise to store potatoes in hampers or
crates. to allow plenty Of ventilation
and thorough curing.
Stem rot can be detected only in the
field. The lesses.grow dull 10 color and
wilt. The disease soon uspresds over
The field. The grower should split the
stems OF plants thought 10 be diseased.
IL found to be stresked with black. it is
a sure sign Of stem rot. 10 the potato
il is indicated by q black rigu. When
wilted plants are found. the hills should
be eliminated. and those nearby also
Another wsy of eliminating this disessy.
is 10 plant vine cuttings for seed. Tn-
same rule that applies to black rot. r, :
garding the rotation Of land. making rf
hot beds. dipping and storing Of pota.
toes, applies in the case Of this disessc
Other diseases and their remedies v
be discussed in later article.