EXPERIMENTS WITH INSECTICIDES UPON POTATOES. 185 



THE FIELD NOTES ARE AS FOLLOWS: 



July 23, five pounds of Bug Death (at the rate of 40 pounds 

 per acre) applied. Bugs in all stages of growth, but not very 

 numerous. 



July 24, bugs not very numerous but apparently happy. Many 

 feeding on eaten plants and no signs of disturbance and no dead 

 ones on the ground. Diligent search failed to show a single dead 

 beetle or slug or a badly eaten plant cleared. Five pounds more 

 (a total of 80 pounds per acre) applied. 



July 25, heavy rain. 



July 27, bugs numerous. Decided to give up use of Bug 

 Death but the superintendent of the Danforth Chemical Company 

 arrived before the plot was treated with Paris green, and at his 

 desire the piece was treated with one package (12^ pounds) or 

 at the rate of 100 pounds per acre. This was applied with the 

 Perfection shaker and it took one man a little less than an hour 

 and a half to apply it. 



August 1, bugs practically all gone. No dead ones to be seen. 

 A few leaves that look as though they had been burned. There 

 was a heavy shower last night and the Bug Death appears to be 

 practically all washed off. 



August 7, practically no bugs. 



August 14, some bugs but less than on the part treated (one 

 application, July 27) with Paris green. The edges of some 

 leaves, especially at east end, are brown. It does not look like 

 blight but more as if they had been burned. 



August 18, blight beginning to appear but considerably less 

 than on other part of piece. Burned leaves are more conspic- 

 uous than on the 14th. 



August 23, burned leaves still more conspicuous, chiefly at 

 east end. Some bugs and blight but not nearly as many or as 

 much as on other part of the piece. 



August 31, pretty generally affected with blight, although not 

 so bad as other part. The so-called burned leaves are practically 

 all dead. They died from the margin of the leaf towards the 

 center. Very different from the w r ay that the other plants have 

 acted with blight. 



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