EIGHTEENTH ANNUAL MEETING. 



^59 



sorry he had made, to give the impression that the oils are 

 uniformly injurious and that it is not safe to use them. In 

 my experience I have never seen any injurious effect from 

 the use of oib. either on peach, apple, plum or pear trees, 

 and as a pretty good test of the action on young trees, pears, 

 plums and apples and currant bushes, we dipped them in 

 soluble oil and held them under the liquid for one minute, 

 roots, tops and all, and no injury whatever was observed in 

 the trees in any respect. This was a home-made preparation 

 and very similar to a great many of the newer preparations 

 that are appearing on the market. The one thing we must 

 remember and keep always in mind in using the soluble oils, 

 we must first test them to see if they will mix with water. I 

 do not believe there is any danger with a 1 to 15 solution of 

 the well-known soluble oils on the market on any kind of a 

 tree. I have given it a severe test, spraying with crude pe- 

 troleum. Why should we expect ill results from a prepara- 

 tion containing not more than 6 per cent, of petroleum? In 

 our operations with one of our orchards the trees have been 

 sprayed for 6 years with "Scalecide" and have shown no ill 

 effects. 



Mr. Rogers to Prof. Jarvis : Have you known of peach 

 trees having been sprayed for that length of time with oil 

 being all right? 



Professor Jarvis : I do not know about any that have 

 been sprayed for more than three years. But I cannot see 

 where there can be any harm ; there is nothing in the oil to 

 accumulate and cause ill effects ; when the rains come they 

 wash the oil away. I repeat, I can think of no reason why 

 oil sprays should harm any trees, if properly used. 



Member: How long should soluble oils be applied to 

 trees to be effective before the rain washes it off? 



Prof. Jarvis: I believe the oil should be on the trees 

 from 24 to 2)6 hours, and probably longer, to be effective. If 

 rain should come and wash the spray off within 24 hours 

 after application, I would advise a second spraying. The 

 oil is thoroughlv soluble and as the rain comes it becomes a 



