BETTER FRUIT 



Pioneer Horticultural Journal of the Pacific Northwest 



Entered as second-class matter April 22, 1918, at the Postoffice at Portland, Oregon, under act 



of Congress of March 3, 1879 



Volume XVI 



Portland, Oregon, August, 1921 



Number 2 



Spraying Methods to Improve Pest Control 



By Leroy Childs, Superintendent Hood River Experiment Station of the 

 Oregon Agricultural College 



SPRAY, appliances, methods and equip- 

 ment have passed through a rather 

 rapid revolutionary process during the 

 past few years. A very few years ago a two 

 or three horse power sprayer was considered 

 a "real outfit" — it was a long step forward 

 when contrasted with the barrel pump out- 

 fit, but in reality this machine was a mere 

 plaything when compared to our 10 and 15 

 horse power machines of today. 



The development of the spray gun made 

 necessary the production of much more 

 power in order to produce and maintain 

 sufficient pressure to operate the gun ef- 

 fectively. Just what is the ideal capacity and 

 horsepower needed for the orchardist of 

 moderate holdings has not been thoroughly 

 established yet. It appears to the writer that 

 some of our modern machines are over 



supplied with horsepower for the amount 

 of work that they are actually required to 

 do while still others are being made de- 

 cidedly under the needed capacity. It mutt 

 be remembered that spraying with guns can 

 not be properly accomplished with entire 

 effectiveness unless applied with adequate 

 power. An over supply of horsepower rep- 

 resents waste, not only in actual operation, 

 but depreciation on horsepower not utilized. 

 It must be remembered that this unused 

 horsepower was paid for at the time of the 

 purchase and wears out along with the 

 power being actually used. 



We are inclined to jump from one ex- 

 treme to another in our enthusiasm ; experi- 

 ence, however, brings about a balance which 

 will work out in the case of sprayers of 

 economical and efficient construction. The 



requirements of an all around, effective 

 machine for the orchardist of moderate 

 holdings are probably not all understood at 

 the present time, though these requirements 

 are gradually assuming definite shape. 



The only spray thrown from a spray gun 

 that will meet all requirements In Insect and 

 disease control is one that Is finely broken 

 up, is misty, and not of coarse or stream- 

 like consistency. Some insect pests and plant 

 diseases may be controlled by applying a 

 spray in coarse form — many can not be so 

 controlled — all can be handled by a fine 

 mist-like spray provided the outfit handles 

 enough per minute and possesses sufficient 

 power back of it to put this finely broken- 

 up spray in all parts of the tree. Many 

 small sprayers (two or three horsepower ca- 

 pacity) can maintain a pressure of 275-300 



Tuo ty[ics of spray thrown from a gun. For close range work the broad fan-shaped spray should be employed. The tops may be covered 

 by using the narrower form. Avoid drenching; this often occurs before the art of spraying is mastered. 



