30 THE MONTHLY BULLETIN. 



These western miscible oils on the market are made from both high 

 and low gravity oils, and are made for different purposes, both for 

 winter and summer spraying. 



It should be noted that these western petroleum oils are probably 

 a little more vicious in their action than eastern oils, and contain 

 large amounts of sulphur in different forms, whereas the eastern oils 

 do not. Furthermore, the western oils all have a much higher cold 

 test and do not congeal when sprayed on the tree at low temperatures 

 as do those which are used in the East from a paraffine base oil. The 

 fact that eastern soluble and miscible oils made from a paraffine base 

 oil tend to congeal might account for the fact of their causing injury 

 in the East where continually used by clogging up the pores of the 

 trees, whereas the western oils by remaining more limpid have not 

 caused injury from continued usage. 



It might be stated in this connection that a number of growers 

 throughout California, Oregon, Washington and Idaho are trying out 

 all these treatments, which seem the best, and these demonstrations 

 will be reported at a later date. 



The time of application for a dormant spray against the apple 

 aphids is of vital importance. In the experimental work, judging 

 from the time the trees came out, it would have been better if the 

 spraying had been delayed about one week. Late winter spraying or 

 spraying just before the buds start to swell is undoubtedly the best 

 time for applying these aphis treatments. This is especially desirable 

 where lime sulphur is used or nicotine is used in any form, and prob- 

 ably Avould help where any of the heavier oil emulsions are used. 



If any of the above sprays do not kill all of the aphis eggs most all 

 of the stem mothers will expire in trying to settle on the buds or 

 twigs. 



RECOMMENDATIONS. 



As far as can be determined at present under western conditions 

 it is believed that dormant treatment for the eggs of the apple and 

 purple aphides should be either commercial Crude Oil Enmlsiou, 1 to 9 

 or 1 to 10 (where the concentrate contains about 85 per cent crude 

 oil) ; homemade Crude Oil Emulsion from 10 to 15 per cent strength 

 made from a crude oil running 19° to 23° Baume; commercial Lime- 

 Sulphur at 1 to 6 or 1 to 7, and the application inade as late in the 

 winter as possible before the buds start to show green. 



If homemade Distillate Oil Emulsions are used they should be made 

 from heavy distillate, and the dilution in the tank figured to run 7 or 

 8 per cent oil. 



