Experiment V The Effect of Mineral Oil on Budworm Control with Toxaphene
and DDT Emulsions. Toxaphene (8 lb/gal) EC was used at 1.5 pints per
100 gallons, DDT (2 Ib/gal) EC at 4 pints, and Sun Superior Spray Oil 7-E
at 10 pints. Planting and application procedures are the same as in
Experiment III with the exception that the weekly spray scheduled for
April 14 was omitted in this experiment because some of the plots were
showing mineral oil burn. Weekly sprays were resumed on April 21.



 Percent Budworm Damaged Plants
 Treatments April 15 April 21

 DDT 1 18
 DDT Oil 0 1 16
 Toxaphene "11 35
 Toxaphene Oil 3 24
 Untreated 15 28


 It seems that the addition of the mineral oil had a greater effect
 on toxaphene sprays than on DDT sprays. The plant damage from mineral oil
 was very slight to slight but perhaps a strong indication that we are
 using it too often or at too high a rate. The poor control obtained on
 April 21 was probably caused by too long an interval since the previous
 spray.


 CONTROL OF EARTORMS ON SIEET CORN
Experiment I Spray Gallonages and Intervals Between Applications for
Earworm Control. Florigold 107 sweet corn that silked on May 6, 1963,
and was harvested on May 24, was sprayed from May 7.until May 23.
One gallon of DDT (2 Ib/gal) EC per acre was applied in 12.5, 25, and
50 gallons of spray per acre at 1-day and at 2-day intervals. In
untreated check plots, 46 percent of the earworms were corn earworms,
Heliothis zea (Boddie), and 54 percent were fall armyworms, Laphygma
frugiperda -(. E. Smith).



Gallons
per Acre Spray Frequency Percent Worm-free Ears

12.5 every day 56
12.5 every other day 42

25 every day 74
25 every other day 56

50 every day 74
50 every other day 58


Untreated


100