POTATO INVESTIGATIONS LABORATORY
Mimeo Report 60-6
November 30, 1959
AN ADDITIONAL CONTROL FOR THE SOUTHERN POTATO WIRE1ORM
R. B. Workman
The Pesticide Regulation Section, USDA, has recently approved the use of
the insecticide, Diazinon, as a preplanting soil treatment for the control of
the southern potato wireworm.
One year's testing at Hastings has shown that Diazinon gives excellent
control of the southern potato wireworm at one and two pounds actual toxicant
per acre and persists in the soil for 9-15 weeks. Parathion has also given
excellent control at one and two pounds actual but remains effective for only
about three to five weeks. Diazinon is safer to use than parathion, being
somewhat less toxic to mammals than heptachlor.
For the reasons of increased residual effectiveness and safety, Diazinon
is being recommended for trial by the growers of the Hastings area in the
control of the southern potato wireworm.
Apply the insecticide
ately. Thorough mixing of
of soil is very important.
of 100-150 psi will reduce
to the soil prior to planting and disk in immedi-
the insecticide into the upper four to six inches
Lowering of the spray nozzles and using a pressure
the amount of spray drift.
Table 1.- Insecticides recommended for control of the southern potato wireworm
in the Hastings area.
Inecticide Amont* Per Acre N
Parathion 4 Emul. 2 qts. (2 lbs. actual) Preplanting soil treatment.
Diazinon 2 Emul. 2-4 qts. (1-2 lbs. actual) Preplanting soil treatment.
*Amounts listed bear the approval of the Food and Drug Administration.