The rate of sprayer travel has a direct effect since air 

 velocity loss is proportional to the forward speed. Speeds 

 above 2.5 mph for standard trees and 3.0 mph for dwarf trees 

 are not recommended. 



Evaporation rate of the droplet and droplet impingement is 

 directly correlated with relative humidity of the ambient air. 

 Spraying during low humidity (.35-50% R.H.) periods should be 

 avoided, particularly with rates less than 30 gpa. 



Spray distribution in the tree as well as undesirable spray 

 drift is greatly influenced by wind conditions at the time of 

 application. No reliable tests under known wind conditions 

 have been conducted to measure effect on pesticide distribution 

 and deposits. 



The level of pest control obtained is correlated with inoculum 



or population pressure and the amount of pesticide applied. 



The lowest deposits and level of pest control are in the top 

 of trees. 



It is important to keep any sprayer properly adjusted to obtain 

 maximum performance. Frequently checks on pump pressure, 

 nozzle wear, operator speed and air delivery are essential to 

 dependable sprayer performance. It is particularly important 

 that the air velocity of airblast sprayers with shear-type 

 nozzles be checked frequently and maintained at between 165-200 

 mph. 



Accurate calibration of airblast sprayers is essential for the 

 uniform application of orchard pesticides. (Details of proper 

 arrangement of nozzles to obtain proper distribution pattern for 

 conventional airblast sprayers are given in Figure 1.) 



Upper 2/3 

 Effective 

 Airblast 



-3 

 1-2.5 



Lower 1/3 

 I-OFF 



Effective 

 ^"2.5 Airblatt 



''OFf 



REAR VIEW 



OFF-hCV 



2 5-t-O 



OFFH-o 



50%» 3.86 GPM 

 (3.76) 



35% = 2.66 GPM 

 (2.72) 



IS*- I.I4GPM 

 (113) 



SIDE VIEW 



100 GPA - 15.2 GPM (76 GPM/side) 

 ROMS 30 ft Speed 2.5 MPH 

 2 Hole Whirl Plote - 200 PSI 



