95 



save the youDg: apples from dwarfing by the insects. In all 

 of our work we are using spraying machines of great 

 I'ower and we prefer rather coarse nozzles, because the in- 

 creased power gives us in this case a driving misty spray. 

 If you do not have sufficient power, then it seems ta mc that 

 for most of the spraying of your fruit you should use noz- 

 >-les with fine apertures. As for the plant lice, there is little 

 question that a driving spray is more efficient than a 

 "misty" spraj^ 



A ME:\IBEII: How much power? 



PEOF. PARROTT : The question is asked as to how 

 ii^uch power one ought to have to kill plant lice. The 

 amount of power depends of course on the size of the 

 apertures of your nozzles. In all cases it should be sufficient 

 to cause the spraying mixture to strike the insects with con- 

 siderable force. 



A MEMBER : AVhat does the pressure gage register ? 



PROF. PARROT: In most of our orchard spraying we 

 use from 200 to 250 pounds pressure. 



MR. FROST: What size opening in the nozzle? 



PROF. PARROTT : Rather coarse apertures. For ordi- 

 i:ary orchard spraying against scab and codling moth 125 

 to 150 pounds is of course sufficient, but owing to the fact 

 that we have such a large acreage and are now fighting 

 buch insects as plant lice and red bugs, we use machines of 

 great power and nozzles with large apertures to get over the 

 trees quickly and do effective Avoifk. 



A MEMBER : Wouldn 't it be more reasonable to think 

 ihat a mist spray striking the back of your aphis would hold 

 on rather than a heavy stream driven to it like a fog and 

 covering it over? 



PROF. PARROTT: Unfortunately it is not the spray 

 on the back of the insect that kills him, it is the material 

 that reaches his breathing organs. A good volume of spray 

 applied with considerable pressure leaves no opportunity 

 for an insect to escape a thorough wetting by the spraying 

 liquid. 



