222— 
The various sulphur plet experiments were started from May 16 to 
June 24, the infestation in the different plats ranged from light to 
heavy, and the number of effective applications ranged from.two to 
five per plat; consequently, the results of these experiments are 
probobly in line with what should “be expected under average dusting 
conditions in the field. The final yield of cotton from the different 
plats showed that the sulphur was more effective in controlling the 
cotton flea hopper than was the mixture or the sodium fluosilicate, 
and that the mixture was more effective than the sodium fluosilicate. 
The 11 plats dusted with sulphur averaged 230.4 pounds of seed cotton 
per acre, or 33.6 percent, more than the 11 corresponding check plats, 
the increase in yield ranging from 88 to 411 pounds. : The 6 plats 
dusted with the mixture produced an average of 145,2 pounds, or 23.8 
percent, more cotton than the 6 corresponding check plats, the range 
being from —4 to 304 pounds. The 4 sodium-fluosilicate. plats yielded 
an average of 101 pounds, or 13.9 percent, more than the 4 check 
plats, the range being from ~46 to 196 pounds, ‘The average cost of 
treatment of the 11 plats dusted with sulphur was $2.54 per acre, © 
or approximately 50 cents per acre~application, counting the cost of 
applying the dust (labor, machinery, etc.) at ®5 cents per acre- © 
application and the cost of the sulphur ate 1/4 cents its pound. 
Ordinarily the seed will séit for enough to enesveate ofatie 
picking and ginning of the cotton, Figuring the value of the lint 
cotton at 12 cents per pound, the 230.4 pounds of seed cotton, or 
76.8 pounds of lint cotton, would be worth $9.22. Deducting the 
cost of dusting, $2.54 per acre, the average net gain from the ine - 
creased yield as a result of the sulphur dusting was $6.68 per acre... 
The mixture cost 9 cents per pound. . ‘The cost of applying. the dust 
is figured at 25 cents per acre- ~application, the same as above, 
A total of 244.75 pounds of the mixture’ was used on the 6 plats, 
making the cost of the insecticide $3. 6/ per acre, The average cost 
of applying the dust’ was $1.42 per acre, making the total cost of 
dusting the mixture, $5.09 per acre, or. 90 cents per acre-application. : 
The average increase in seed cotton per acre in the mixture—dusted 
’ 
a cat oP ee 
plats‘ over the checks was 145,2 pounds, or 48.4 pounds,of lint cotton.:.... 
‘ The value of this lint cotton at 12 cents per pound would be; $5.31,. 
‘ Subtracting $5.09, the cost of dusting, the average net gain fron 
the incréased yield as a result of dusting with the mixture was {e. 
cents per acre. The average cost of treatment of the 4 plats dusted 
‘with sodium fluosilicate was 46. 35 per acre, figuring the sodium 
fluosilicate at 8 cents per pound and the cost of applying the dust 
at 25 cents per acre-application, The sodium-fluosilicate plats 
yielded an average of 101 pounds of seed cotton per acre more than 
the check plats. Figuring the value of this cotton on -the same basis 
as for the above plats, the gross gain of the dusted plats over the 
checks would be $4,04 per acre. Subtracting the value of the in- 
creased yield of cotton, $4.04, from the cost of the dusting, $6.35, 
gives a net loss of $2.31 per acre as a result of dusting with sodium 
flvosilicate. 
+o Fe 1h se 
