1. Calibrating Spray Equipment
Page 69

2. Why Calibrate Better Pest Control Environmental and human safety
Effective use of time
Inadequate control = more treatments
Cost/Benefit ratio
Lack of calibration = improper mixing
1 gallon of Tordon per 100 gallons of water
Will revisit

3. What’s An Application Rate
Gallons of liquid applied per acre
GPA
Water and pesticide mixed
a.k.a.
Sprayer volume
Sprayer output
Need to know GPA for mixing

4. Variables Affecting GPA
Ground Speed (MPH)
Speed up = less liquid = lower application rate
Slow down = more liquid = increased application rate
Consistency

5. Variables Affecting GPA
Nozzle Flow Rate
GPM
Depends on
Orifice size
= 0.50 GPM
= 0.20 GPM

6. Variables Affecting GPA
Pressure
4x pressure to double GPA
Increased pressure = smaller droplets
Drift
For Minor Adjustments Only

7. Variables Affecting GPA
Spray Width or Spacing
100% swath overlapping doubles output

8. Variables Affecting GPA
Nozzle Wear
Worn tips =
Over application
Erratic patterns

9. Figuring Out GPA
Label requirements
More GPA = More Coverage

10. Figuring Out GPA Label requirements Determine Your Field Speed
Know it to maintain it!
200 Feet in 27 seconds
200 27
X 0.682
= 5 MPH
Buy a speed sensor

11. Figuring Out GPA Label requirements Determine Your Field Speed
Collect from each nozzle
- Find GPM
64 ounces
Ounces oz. Per gallon
= 0.5 Gallons
= Gallons

12. Figuring Out GPA Label requirements Determine Your Field Speed
Collect from each nozzle
Want output of one nozzle
Simply plug in the numbers

13. GPA is given or required! Need GPM for each nozzle!
Rearrange formula

14. How Much To Add To The Tank
Acres that can be sprayed with a given volume in the tank
GPA
Labeled Rate

15. How Much To Add To The Tank
Acres that can be sprayed with a given volume in the tank
Volume GPA
= Acres
500 gal. 25 GPA
= 20 Acres
20 Acres x 25 GPA = 500 gallons

16. How Much To Add To The Tank
Acres x labeled rate per acre
Acres that can be sprayed with a given volume in the tank
GPA
Labeled Rate
Gallons?
20 acres x 3 pints/acre
= 60 pints
60 pints 
8 pints/gal.
= 7.5 gal.

17. 1 gallon of Tordon per 100 gallons of water
- Sprayer applied 50 GPA
- Could spray 2 acres with 100 gallons
100 gallons  50 GPA = 2 acres
- Rate was 1 quart per acre
- Only needed to add 2 quarts per gallons
2 acres x 1 quart per acre = 2 quarts per 100 gallons
- Over applied by 2x ($40 per acre)