-lkG- 
Dual-fixed- nicotine dust applied on the same dates resulted in 75 percent 
of borer-free ears in contrast to Uo percent on the untreated check. The 
same station (j^) in 1939 reported that further trials using pure ground 
cube root (*U percent rotenone) at the rate of 1 pound in 25 gallons of water 
with a suitable spreader, indicated the effectiveness of this material 
against the corn borer, especially when used in August against the second 
generation. Three applications on early corn at weekly intervals were al- 
most as effective as four at 5-day intervals. Five applications at 5-day 
intervals were more effective on late corn than four at weekly intervals. 
Seven weekly applications of rotenone dust (1 percent rotenone in pure 
ground cube) or of pure ground cube root (h percent rotenone) 1 pound in 
2!? gallons with a suitable spreader protected dahlias against the corn borer, 
but the cube spray was somewhat less effective than the dust. 
Parks and Pierstorff ( 32^- ) in 193S recommended derris spray (U lb. per 
100 gal. of water plus 3 °z. °f sulfated alcohol spreader) to control borer 
on sx^eet corn. 
Pepper ( 328 ) in 193& reported that nicotine bentonite dust and ground 
derris or cube-root dust have proved more satisfactory than other dust 
materials tested in reducing damage. Nicotine bentonite dust gave slightly 
better protection than derris -root or cube-root dust. Derris-root or cube- 
root dust was made by mixing 19 pounds of finely ground derris root or cube 
root (U percent of rotenone and l6 percent or more of total extractives) , 
1.6 ounces (by weight) of wetting agent, and SI pounds of talc. If desired, 
25 pounds of dusting sulfur may be substituted for 25 pounds of talc. The 
derris-root or cube-root dust is easier to mix at home than the nicotine 
bentonite dust, as the nicotine bentonite dust tends to pack when mixed in 
a ball mixer. Each application of dust should be made at the rate of 25 
to 30 pounds per acre. In experimental plots of the Few Jersey Agricul- 
tural Experiment Station nicotine bentonite, derris-root sprays, and cube- 
root sprays consistently gave good results. Derris or cube (k percent 
rotenone) spray at U pounds per 100 gallons of water plus 5 ounces of 
wetting agent is also recommended. 
O'Kane ( 319 ) in 1939 reported that derris powder plus Ultrawet made 
a safe and effective spray. 
According to Haude in advertising literature Published by John Powell 
and- Co., New York, H. Y., in 1939, the Connecticut Experiment Station re- 
ports good control of this insect by a spray of finely powdered derris (U 
percent rotenone) at the rate of U pounds per 100 gallons of water. 
Hervey and Carruth ( 188 ) in 1939 reported that powdered derris root 
(5 percent rotenone), used at the rate of U pounds to 100 gallon of water 
with a suitable spreader, gave very good control at Albany, 1'T. Y. Four to 
5 treatments were necessary to protect the rapidly growing cor:. ta 
during the egg-laying season. The treatments were begun when the first 
eggs started to hatch and continued until shortly after c. ing rc.ichod 
a peak. Certain fixed-nicotine dusts and spray a also reduced borer popula- 
tion but were less efficient than the derris spray. In order to reach the 
newly hatched borers, which feed between the loaves in the cro'-'n of the 
plant, one of the newer wetting or spreading agents should bo used to re- 
duce the surface tension and cause the mixture to penetrate the spaces 
where the insects are feeding. 
