MISCELLANEOUS INSECTICIDE INVESTIGATIONS. 



33 



against 99.44 per cent for 2 pounds of the paste. The unsprayed 

 trees yielded 47,866 apples, of which number 58.71 per cent were free 

 from codling-moth infestation. 



Experiment XVIII. 



FIELD TESTS OF VARIOUS ARSENICALS COMBINED WITH FUNGICIDES AGAINST THE 



CODLING MOTH, 1914. 



Arsenate of lead was tested against the codling moth in combina- 

 tion with the following commercial fungicides, namely, lime-sulphur, 

 commercial; precipitated sulphur, commercial; sodium sulphid, com- 

 mercial ; and commercial barium tetrasulphid compound. The follow- 

 ing combinations were also tested : 



Arsenite of zinc (paste) was used at the rate of 1§ pounds combined 

 with Bordeaux mixture 4-4-50. This arsenical was added to the 

 lime while being slaked for the Bordeaux mixture. 



Arsenite of zinc (paste), 1J pounds, was added to 2 pounds stone 

 lime while the lime was slaking. This was mixed with 50 gallons lime- 

 sulphur solution. 



Arsenate of zinc (homemade), prepared from sodium arsenate 

 crystals and zinc sulphate, was used at the rate of eight-tenths pound 

 sodium arsenate to 50 gallons lime-sulphur solution. Three spray 

 applications were made with the above combinations. The results 

 of this experiment will be found in Table XVIII. 



Table XVIII. — Sound and wormy apples from sprayed and unsprayed plats. 

 [Poison test. Miscellaneous. Benton Harbor, Mich., 1914.] 



Plat 

 No. 



Treatment. 



Tree 

 No. 



Condition of fruit. 



Wormy. 



Sound. 



Total. 



Per cent 

 sound. 



I 



Arsenate of lead (paste), 2 pounds to 50 gallons 

 lime-sulphur solution. 



Plat total 



1 

 2 

 3 

 4 

 5 

 6 



29 

 12 

 28 

 13 

 26 

 26 



3,777 

 2,399 

 5,146 

 3,833 

 3,972 

 4,757 



3,806 

 2,411 

 5,174 

 3,846 

 3,998 

 4,783 



99.24 



99.59 

 99.46 

 99.66 

 99.35 

 99.46 





134 



23,884 



24,018 



99.44 





Arsenate of lead (powder), -J pound + commercial 

 precipitated sulphur, 7 pounds, to 50. 



Plat total 



1 

 2 

 3 





II 



44 

 93 



82 



5,618 

 8,958 

 7,791 



5,662 

 9,051 

 7,873 



99.22 

 98.97 

 98.96 





219 



22,367 



22,586 



99.03 





Arsenate of lead (paste), 2 pounds + commercial 

 sodium sulphid, 2 pounds, to 50. 



Plat total 



1 

 2 

 3 





III 



72 

 30 

 34 



7,898 

 7,784 

 8,739 



7,970 

 7,814 

 8,773 



99.08 

 99.62 

 99.61 





138 



24,421 



24,557 



99.45 





Arsenate of lead (paste), 2 pounds + stone lime, 

 2 pounds + commercial sodium sulphid, 2 

 pounds, to 50. 



Plat total 



1 

 2 

 3 





IV 



35 

 22 

 39 



8,295 

 6,269 

 9,639 



8,330 

 6,291 

 9,678 



99.58 

 99.65 

 99.60 





96 



24,203 



24,299 



99.65 











