A SERIOUS LETTUCE DISEASE. 
113 
TABLE VI.—SHOWING TOXICITYvOF VARIOUS FUNGICIDES. 
+ = viable; —■ = not viable. 
Fungicide 
Strength 
10 
Min. 
1 Hr. 
24 
Hrs. 
Ammoniacal Copper Carbonate- 
Copper Carbonate, 6 ozs.; Ammonia, 3 pts.; 
+ 
H 2 O 50 gals. 
Bordeaux Mixture.-. 
5 lbs. CuSCb, 5.lbs. Lime, 50 gals. H 2 O_ ... 
+ 
— 
— 
Bordeaux Mixture_ ___ 
2 lbs. CuSCb, 2 lbs. Lime, 50 gals. H 2 O 
+ 
Potassium Sulphide_ _ _ _ . 
1 oz. Potassium Sulphide, 1 gal. H^O 
+ 
+ 
+ 
Potassium Sulphide_ . _ 
1 oz. Potassium Sulphide, 3 gals. H>0 
+ 
+ 
+ 
Lead Acetate . __ 
1 oz. Lead Acetate, 1 gal. H 2 O 
+ 
+ 
+ 
Lead Acetate. . __ . 
4 ozs. Lead Acetate, 1 gal. H 2 O ..... 
+ 
+ 
+ 
Potassium Permanganate. . 
1 oz. Potassium Permanganate, 1 gals. H 2 O- 
Potassium Permanganate _ 
1 oz. Potassium Permanganate, 3 gals. H 2 O- 
— t 
— 
— 
Potassium Permanganate_ 
1 oz. Potassium Permanganate, 5 gals. H 2 O- 
— 
— 
— 
Potassium Permanganate 
1 oz. Potassium Permanganate, 7 gals. H 2 O- 
— 
— 
— 
Potassium Permanganate 
1 oz. Potassium Permanganate, 10 gals. H 2 O_ 
+ 
— 
— 
Formalin_ . . 
1 oz. Formalin (40 %), 1 gal. H 2 O_ .. 
+ • 
_ 
___ 
Formalin 
1 cz. Formalin (40 %), 2 gals. H 2 O ... _ 
+ 
Formalin... ... _ _ 
1 oz. Formalin (40 %), 3 gals. H 2 O_ 
■ + 
• + 
+ 
Sodium Eenzoate.. .. . . 
1 oz. Sodium Benzoate, 1 gal. H 2 O_ ... 
+ 
+ 
+ 
Sodium Benzoate.. _ .. . 
1 oz. Sodium Benzotte, 2 gals. H 2 O .. 
+ 
+ 
+ 
Sodium Benzoate.. . 
1 oz. Sodium Benzoate, 5 gals. H 2 O__ 
+ 
+ 
+ 
Sodium Benzoate-Bordeaux.. 
y ,1 lb. Sodium Benzoate, 1 lb. CuSCh, 1 lb. 
Lime, 50 gals. H 2 O 
Iron Sulphate_ _ _ 
15 %_ 
+ 
+ 
+ 
Lime Water__ __ . 
Saturated . _ 
+ 
Lime Paste __ _ _ . ._ 
• 
. 
.1 • 
• 
Potassium sulphide, 1 ounce to 3 gallons and 1 ounce to 1 gallon, 
lead acetate 1 ounce to 1 gallon and 4 ounces to 1 gallon, formalin 
1 ounce to 3 gallons, sodium benzoate 1 ounce to 1 gallon, 1 ounce to 
2 gallons, 1 ounce to 5 gallons, and iron sulphate were not fatal even 
w T ith a twenty-four-hour application. 
Potassium permanganate 1 ounce to 1 gallon, 1 ounce to 3 gallons, 
1 ounce to 5 gallons, and 1 ounce to 7 gallons, lime paste and sodium- 
benzoate-Bordeaux (one-half pound sodium benzoate, 1 pound copper 
sulphate, 1 pound lime to 50 gallons) were fatal even with the shortest 
period tested. 
The inefficiency in these comparatively strong solutions of potassium 
sulphide and of formalin indicates considerable vigor and resistance 
on the part of the fungus. 
Experiment 19. Copper sulphate was tested following the method 
of the last experiment, using strengths varying from 17/100 to b7/6400 
and varying the time from 5 to 105 minutes. With the three weaker 
strengths, tests were made continuing to twenty-four hours. The tests 
were made with the solutions at a temperature of 17 degrees. The 
results are shown in the following table: 
