22 



the dust. We want to go over our methods and our arrange- 

 ments, and I want to say that those who will do so will do a 

 better job with less material wasted. 



Now, another interesting thing. Professor Saunders devel- 

 oped a Bordeaux dust which promises to be as effective as 

 liquid Bordeaux. He found that where he dusted with this 

 Bordeaux dust on apples and compared with it spraying with 

 Bordeaux, although he put 75 gallons of material on in spray- 

 ing and only 50 pounds in dusting, that he actually got more 

 copper on the leaf surface by dusting than he did by spraying. 



In other words, the actual wastage of copper was less in the 

 dusting than it was in the spraying, a thing nobody suspected. 

 The chemist actually found a higher percentage of copper on 

 dusted trees than he did on sprayed trees, so the actual wast- 

 age under present conditions in that orchard where he was 

 using Bordeaux in both cases w^as less for dusting than for 

 spraying. 



Chairman Jenks. What is the smallest acreage you would 

 suggest putting on the dust at its present stage of development? 



Professor Whetzell. I would leave that to the individual. 

 I never recommend anything. That is one thing I want you 

 to remember when you go away from here, — Whetzell did 

 not recommend a single thing. I am trying to give you the 

 facts as I have them and my opinion, which you can take for 

 whatever it is worth, but if you go home and buy a duster and 

 it doesn't work, don't look at me. 



Chairman Jenks. What do you think of soluble oil as com- 

 pared with lime-sulfur? 



Professor Whetzell. In the first place, soluble oils are used 

 primarily to control insects, scale, and so forth. They are not 

 used as fungicides to any extent. I have no information on it. 

 I have carried on no experiments, and I do not know. The 

 only thing I can imagine soluble oils used for in a fungicide is 

 disinfecting peach trees for curl. 



Chairman Jenks. The question is asked how about the 

 sooty blotch on apples? 



Professor Whetzell. It can be controlled by any of the 

 spray mixtures you use. You have got to put on a later 



