EXPERIMENTS WITH INSECTICIDES AND FUNGICIDES. I45 



PARIS GREEN, BUG DEATH AND ARSENATE OF LEAD COMPARED. 



Kind and amount of insecticide, the weighed yield of potatoes, 

 and the starcli content of the merchantable potatoes. Bordeaux 

 mixture was used five times on each plot. 



Insecticides Used, Kind. 



o 



on 



9 

 10 



11 

 12 



Paris green 



Bug Death 



Arsenate of lead. 



Paris green 



Bug Death 



Arsenate of lead. 



Paris green 



Bug Death 



Arsenate of lead 



Paris green 



Bug Death 



Arsenate of lead. 



Average Paris green 



Average Bug Death 



Average Arsenate of lead. 



lbs. 



21 



60 



4 



ia 



126 



24 

 4 



75 



8 



S 



100 



16 



bush 

 295 

 315 

 285 

 305 

 29fi 

 295 

 285 

 320 

 3-20 

 370 

 350 

 365 



bush 

 36 

 34 

 27 

 26 

 34 

 29 

 25 

 23 

 27 

 34 

 25 

 26 



314 31 

 319 29 

 318 I 27 



I 



bush 

 32 

 23 

 25 

 40 

 35 

 80t 

 68 1 

 55 1 

 50t 

 28 

 35 

 41 



42 

 37 



49 



bush 

 363 

 372 

 337 

 373 

 359 

 4ii4 

 368 

 398 

 397 

 432 

 410 

 432 



3t4 

 385 

 393 



per ct. 

 21.28 

 21.28 

 21.41 

 21.41 

 22.06 

 18. 84 

 19.50 

 18.46 

 19.19 

 19.46 

 18.25 

 18.87 



20.41 

 20.01 

 19.58 



* There was no soft rot. This includes all discolored potatoes. 



t Depressions on part of the field with more rot where the soil was wetter. 



SUMMARY OF RESULTS OF THIS EXPERIMENT. 



At no time during growth were there perceptible differences in 

 color, size or vigor of the vines treated with different insecticides. 

 All these insecticides kept their respective plots sufficiently free 

 from insects to prevent damage ; the smaller amounts of the 

 insecticides were nearly as effective as the larger. The poisons 

 were applied early so that the vines were protected before the 

 bugs appeared. Paris green kept the vines a little freer than 

 Bug Death, and Bug Death acted quicker than arsenate of lead, 

 but all three were effective from the practical standpoint. 



The yield was smaller on the northern side and increased 

 gradually towards the southern side. The yields were fairly 

 uniform on adjoining plots and the average of the results 

 showed practically no differences in the yield from the plots 

 treated with different insecticides. The loss due to rot was 



