The coastland times. [volume] (Mnateo [i.e. Manteo], N.C.) 1947-1959, 1951-02-16
CHLORDANE MIXTURE
PROVED INEFFECTIVE
Hyde Tests Show Poison Applied
At Planting Has Little Value
In Controlling Bugs

4CoCS SOuOuCCCu III 11yuc COuItLy
last year with chlordane-fertilizer
mixtures applied at planting
time proved ineffective in con-
trolling wireworms and billbugs
in corn, DR.. Walter M. Kulash,
North Carolina Experiment Sta
tion entomologist announced Mon
day.
DIR. Kulash conducted labOra-
tory experiments as well as
testing the chlordane-fertiIizer
mixtures in Hyde county last
year. Mixtures containing up to
10 pounds of chlOrdane per acre
killed only about 10 per cent of
the wirewOrms, he found. A
fertilizer mixture containing
two pounds of chlOrdane per ac-
re had almost no effect in con-
trolling billbugs.
DIR. Kulash has been working
for some time to develop control
measures against wireworms, bill
bugs and other soil insects. He
had previously found that chlor-
dane will control the corn wire
worm if applied to the soil well
before planting time.
In his 1850 tests he set out to
determine if chlordane could be
mixed with the fertilizer and ap-
piled at planting time. He con-
Quoted both laboratory and field
trials, and found chlordane-ferti-
lizer mixture ineffective in both
cases.
In the laboratory trials, DR.. Ku-
lash tried both five and ten
pounds of chlordane per acre in
fertilizer mixtures. These mix
lures killed only IL and 8 per
cent of the wireworms, RESPECTIVE
ely, while 80 per cent of the seeds
were injured by wireworms with
in eight days after planting.
The State College scientist con-
cludes that present combinations
of fertilizers and insecticides
won't control wireworms. The rea-
son is simply that the best time
for applying fertilizer is not the
best time for applying the insec-
ticide. Chlordane is too slow in
killing corn wireworms to be eff
fective in protecting the seed and
seedlings when applied at plant
ing time.
An important factor in wire
worm control, Kulash adds, is al
lowing enough time for the poison
to work before planting the crop.
The results of other field tests
with treated soil and treated seed
support this conclusion. Seed
coated with chlordane was at first
unchanged by wireworms. How
ever, after emergence and even
after the plants were four to six
inches high, wireworms attacked
the stem.
High Rates in Hyde
Another point which should be
emphasized is that the rates of
chlordane used in the Hyde Coun-
ty tests were high. Even if high
rates of chlordane were effective
under North Carolina conditions,
they would be expensive.
Chlordane applied in the ferti-
lizer mixture was almost a COM
plete failure in controlling bill
bugs. Billbugs usually migrate
into corn fields from adjoining
areas after corn breaks through
the ground. They continue to at
tack corn for about four to six
weeks. Consequently, an insecti-
eide placed in the ground does not
come in contact with the pests
and does not control them.
Kulash advances one more thing
that should be considered by a
farmer interested in using soil in
secticides: "How will the insecti-
eide affect the plants and the
soil?"
Some plants are more suscepti-
ole TO INJURY from lnSectlcldeS
than others, and the susceptibility
may vary in different soil types.
Furthermore, insecticides such as
benzene hexachloride have given
an off-favor to root crops grown
in treated soil.
Interest in the use of fertilizer
insecticide mixtures for controll-
ing soil insects has been increas-
ing, Kulash says. In some cases,
apparent successful control of soil
pests of corn has been reported.
In South Carolina, for example,
chlordane in fertilizer mixtures is
said to be effective in controlling
the sand wireworm. But this spe-
cies of wireworm is not serious
pest in North Carolina.
The entomologist concludes that
the problems will have to be in
vestigated further before insecti-
cide-fertilizer combinations can
be recommended for general use
under North Carolina conditions.