PRESS BULLETIN 137
Florida Agricullural Experiment SMation
KEEPING CORN FROM WEEVIL
By C. K. McQuarrie
It is generally recognized that the loss to the farmers of Florida from
the weevil pest is, in many cases, from ten to fifteen per cent. of their
whcle crop. And as the value of the corn crop of the State, according to
the statistics of the U. S. Department of Agriculture, is now upwards of six
and a half million dollars, we can figure the annual weevil loss at six
hundred and fifty thousand dollars.
Kind of Cribs Necessary
We can overcome the weevil ravages and clear our cribs of this insect
by the proper and systematic use of carbon bisulphide. To get good results
we must have tight cribs or granaries. It is also advisable to shuck the
corn ears entirely when gathering the crop. The corn crib, as it is generally
found on the Florida farm, is not a good place for successful fumigation;
since it is too open, and allows the fumes to escape into the atmosphere.
But any of these cribs can be put in good condition for the purpose by lin-
ing and ceiling with matched lumber, and making a tightly fitting door. A
crib that will hold four hundred bushels of corn in the ear will measure ap-
proximately 12 by 12 by 6 feet, and seven hundred and sixty feet of lumber
will line and ceil it. With country lumber, nails, and labor, the cost need
not exceed eighteen dollars; as second-grade lumber can be used for the
purpose. The cost of fixing up an ordinary crib will be returned in one sea-
son in the amount of corn saved.
How to Fumigate
Where small quantities of corn are to be treated, it is advisable to use
air-tight barrels for the purpose. Filling them with corn, apply a tablespoon-
ful of the bisulphide in a plate, and close them tightly; subjecting them
to fumigation for a day or two. Then refill the barrels till all the crop
has undergone the treatment. An effective covering for these barrels may
be easily made. The rim of the barrel should be treated with a heavy coat-
ing of thick grease, such as vaseline or axle grease. A sheet of thick paper
Sis laid on the top, and then covered with sacking to keep the paper in
place. In this .way all air is excluded, and fumigation will be complete.
January 8, 1910
The quantity of carbon bisulphide needed depends somewhat on the
kind of crib or granary in use, but there will generally be required about
six pounds of the liquid for a five-hundred-bushel crib. This will cost about
thirty-five cents a pound, retail. But when a large quantity is required, it
can be bought wholesale from some of the fertilizer manufacturers in
Jacksonville, at a considerably lower price.
For holding the liquid, shallow vessels should be used; and soup plates
are excellent for the purpose. These plates should be set on the highest
spots in the crib or barrel, and at distances of not more than five feet apart
in the crib. One vessel to each barrel is enough. The fumes being heavier
than air will penetrate downwards, so it is only when the vessels are placed
on the highest spots that we are sure that the results will be perfect.
In handling carbon bisulphide care should be exercised to keep it away
from fire, and no smoking should be allowed in its vicinity, because the
vapor is very explosive and will light with a spark. Carelessness in this re-
spect might result in serious accidents.
Faulty Cultural Methods
The methods of corn culture and saving the crop, as generally practiced
by the average farmer in Florida, tend to make the corn susceptible to the
ravages of this insect.
The practice of fodder-pulling in vogue tends to stop the full develop-
ment of the grain on the cob, thus leaving ample space for the weevil to
get possession and lay eggs in abundance to perpetuate its kind. As the
life-cycle of this insect is only forty-five days, it may have eight or more
broods every year. and we can readily understand why it is so destructive.
The fodder-pulling practice also tends to loosen the shucks on the ears
from exposure to the sun, wind, and rain, during the time the stalk is left
standing in the field. So that to prevent weevil destruction as far as pos-
sible, better farming methods should be adopted; such as shallow and con-
stant cultivation during the growing period to promote well-developed ears,
and cutting and shucking the crop, so as to insure thorough curing under
the best possible conditions.
State papers please copy.