REPORT OP STATE DAIRY COMMISSIONER 



445 



each lot of tankage analyzed before it leaves the factory. From 

 samples of rendering house tankage submitted to the laboratory it is 

 our opinion that very little of this product is suitable for feeding 

 tankage. Much of it should be used for fertilizer. 



Filling - the Cans — An interesting- part of the job of putting up Iowa's 



sweet corn crop. 



INSECTICIDES AND FUNGICIDES 



The law regulating the sale of insecticides and fungicides in Iowa 

 became effective in 1917 and since that time fruit raising has become 

 an industry of considerable proportions. The orchardist and the 

 farmer with only a small orchard has found that without proper 

 spraying of his fruit trees the crop is of little value. 



The State Horticultural Association and the extension service of 

 the state college has been instrumental in instructing fruit growers 

 how to care for their trees and in the use of proper spraying mate- 

 rials. In order to determine the quality and the truthfulness of the 

 labels on these products the department has analyzed a large number. 

 Arsenicals must contain their arsenic in combined form and too 

 much water soluble arsenic must be avoided, as it will affect the 

 foliage. It is the chemical compounds of arsenic which adhere to 

 the foliage and wood of the tree that destroys the insects and fungi. 



There is very little discrepancy between the branded analysis and 

 that found by the chemists of the department. 



