1. INAG 106 Pesticide Use & Safety Course
Lecture 12: Pesticide Application & Calibration
David Myers
Extension Educator, Agriculture

2. PESTICIDE CALCULATIONS
Determine the amount of product needed
Formulated Product vs Active Ingredient

3. Formulations and Active Ingredient
Dry formulations will report their active ingredient as a % by weight
For example the label for Thalonil states that it is a 90 DF product
Therefore the active ingredient is 90% by weight of the container
If the container weighs 5 lbs then .9 x 5 = 4.5 lbs of active ingredient

4. Formulations and Active Ingredient
Liquid formulations will report their active ingredient in lbs active ingredient per gallon and as % by weight
For example the label for Illoxan states that it is a 3 EC formulation
This means that there is 3 lbs of active ingredient per gallon
If the container size is 5 gallons then one would have 5 x 3 = 15 lbs of active ingredient

5. Formulations and Active Ingredient
For example Diuron 4L is a liquid formulation
Its % active ingredient is 40%. To get the amount of active ingredient in a gallon one would have to multiply .40 by the weight of 1 gallon of this material
Since weight may not be given refer to the lbs A.I. / gallon statement

6. FORMULATED PRODUCT
The Label Contains Information On The Amount of Product Needed Under the “Directions For Use” Section

7. How much Aliette would you need to make up 450 gallons if
you plan to use the lowest possible rate?

8. ANSWER Set up a proportion as follows and solve for x 2.5 lbs
100 gallons
x____
450 gallons =
Label Rate
(100) x (X) = (2.5) x (450)
X = (2.5) x (450)
100
X = 1125
100
X = lbs of Aliette

9. ACTIVE INGREDIENT
If you want to solve for the amount of active ingredient (A.I.) or if you are given the application rate in lbs A.I. then use one of the following formulas.
DRY MATERIAL
(% A.I. As a Decimal) (Form. Product) = lbs of A.I.
LIQUID MATERIAL
lbs A.I = lbs A.I. Needed
gallon formulated prod.

10. PRACTICE PROBLEM
If a 7.5 G insecticide is recommended at a rate of 4.5 lbs A.I./A,
determine how much of the formulated product is needed to treat
4 acres?
Use this formula:
(% A.I.) x (lbs of Formulated Product) = lbs of A.I.
(.075) x (X) = 4.5 lbs A.I.
X =
.075
% A.I. needs to be
expressed as a decimal
X = 60 lbs of product per acre
Remember you have to treat 4 acres therefore multiply 60 x 4
to get 240 lbs of insecticide for the 4 acre area.

11. PRACTICE PROBLEM
A 13,300 sq. ft. area needs to be treated with Daconil 4F.
How much Daconil 4F will be needed if you want to apply
3.5 lbs A.I.per acre.
Use the following formula for a liquid formulation:
4 lbs A.I.
1 gallon
3.5 lbs A.I. X =
You need to treat
a 13,300 sq. ft. area
Solve for X :
(4) x (X) = (1) (3.5)
X = 4
X = gallons of Daconil 4F is needed per acre
13,300
43,560
.305 of
an acre =
(.88 gallons) X (.305 acre) =
.27 gallons of Daconil 4F will
be needed.

12. ACTIVE INGREDIENT PERCENT CALCULATIONS DRY
If you want to make up a % spray solution then the following
formulas can be used. One is for a dry formulation and the other
is for a liquid formulation
PERCENT CALCULATIONS
DRY
(Gallons Spray) (% Spray) (8.3) % A.I. of Pesticide
LIQUID (Gallons Spray) (% Spray) (8.3) (lbs A.I. /Gallon) (100)
8.3 is a
constant and
represents the
weight of 1
gallon of
water

13. PRACTICE PROBLEM
You want to make up a 1.7% spray of Roundup 4 L. You have
a 250 gallon sprayer which you plan to fill. How much Roundup
will be needed? How much water will be needed?
Use this formula to solve the problem :
( % Spray ) ( Spray Volume) ( 8.3)
( lbs A.I./gallon) ( 100 )
Amount of water needed =
( 1.7 ) ( 250 ) ( 8.3)
( 4 ) ( 100 ) =
[ ] = gallons
of water and 8.82 gallons of
Roundup will be added
to give 250 gallons of spray
3527.5
400 =
8.82 gallons of Roundup 4 L will be needed

14. PRACTICE PROBLEM
You want to make up a .75% spray solution of Dursban 50 WP.
How much Dursban will be needed if you want to make up a 30
gallons?
Use This Formula :
( % Spray) ( Gallons of Spray ) ( 8.3 )
(% A.I.)
(.75 ) ( 30 ) ( 8.3 ) 50 =
Note: When using the
percent mix formulas
the % spray and % A.I.
Values are not entered
as decimals
186.75 50 = =
3.7 lbs of Dursban 50 WP

15. PRACTICE PROBLEMS
1. If a 2.5G insecticide is applied at the rate of 3 lbs. A.I./A,
how much of the formulated product is needed to treat
5 acres?
Answer: 120 lbs/A and 600 lbs for 5 acres.
2. A 26,500 sq. ft area needs to be treated. The recommended
application much of the formulated rate is 1.8 lbs A.I./A.
The pesticide is formulated as a 2 EC. How much of the
formulated material will be needed to treat this site?
Answer: .55 gallon or 70 oz

16. PRACTICE PROBLEMS
3. A 1.7% spray of Weedbgone 4L is required for excellent weed control. How much Weedbgone will be needed to treat a 2 acre field? Assume that you want to mix the product in water and apply the mixture at 1 gallon per 1,000 sq. ft.
Answer: 3.1 gallons
4.A fungicide, Nopatho 50 WP, is recommended at a 2 oz per
1,000 sq. ft. rate on the label. How much Nopatho fungicide
is needed to treat 1.75 acres?
Answer: 9.5 lbs

17. CALIBRATION EXERCISES
APRIL 25, 2005

18. CALIBRATION The process by which one determines the
application rate (gallons per acre or pounds
per acre) of equipment under a given set
of conditions.

19. APPLICATION EQUIPMENT
Multipurpose Sprayers : Hand Held Units, Airblast Sprayers, and Spray Booms
Broadcast Applicators for Granular Formulations
Band or Row Applicators for Granular Formulations
Soil Fumigation Equipment
Injection and Implantation Equipment for Trees
Greenhouse Applicators Can Range From Mists, Dusters, Drenches, to Foliar Spray Applicators

20. APPLICATION EQUIPMENT
Each Commodity Has a Separate Write Up in the Commodity Manuals
Agricultural Manual : 10-15
Ornamental and Turf Manual: Nursery and Landscape: Turf : Greenhouse: 51

21. WHY IS IT IMPORTANT TO CALIBRATE?
Damage was due to poor nozzle distribution.

22. Sprayer nozzles set too low thus causing a streaking effect.

23. SPRAYER CALIBRATION
FOUR VARIABLES THAT ONE CAN ADJUST TO GOVERN SPRAY OUTPUT ARE :
1) NOZZLE TYPE
2) NOZZLE SPACING
3) SPRAYER SPEED
4) SPRAYER PRESSURE

24. CONSIDERATIONS IN NOZZLE SELECTION
Spray Product Catalogs Will Provide Important Information In Nozzle Selection
Nozzle Construction
Nozzle Pattern
Nozzle Spacing And Height Above Ground
Nozzle
Screen Which Is Placed Before
Nozzle to Prevent Plugging of Nozzle

25. Example of
Catalog
Information
on Nozzle
Selection

26. CATALOG INFORMATION & INTERPRETATION
65 Degree
Nozzle
80 Degree
Nozzle
Table Interpretation: For nozzle model SS it
has the following characteristics : It is a 65 degree nozzle
and can be used between 30 and 60 psi. If used at 50 psi
it’s output would be .07 gallons per minute (GPM).
Also at a 20 inch spacing and traveling
at 5 MPH the application rate would be 4.5 gallons per
acre (GPA).
110 Degree
Nozzle
Screen
Mesh
Size

27. PRODUCT CATALOG INTERPRETATION
Based on the previous slide answer the following questions:
1. What would be the GPM of nozzle model 8001-SS if used
at 40 psi?
Answer: .1 GPM
2. If this nozzle is placed at a 20 inch spacing and a sprayer
travels at 6 MPH what will its GPA be?
Answer : 5.0 GPA

28. CATALOG INFORMATION
The height of the nozzle above the spray boom is important so as
to ensure uniform application. The table below shows the
recommended height for different spray nozzles spaced at 20” to 40”.
NOZZLE HEIGHT
SPRAY
ANGLE
20”
Spacing
NOZZLE TYPE
30”
Spacing
40”
Spacing

29. NOZZLE CONSTRUCTION Brass Polymer Stainless Steel
Hardened Stainless Steel
Ceramic
Nozzles will wear differently based on their construction .
Refer to the following slide on wear differences.

30. Brass nozzles wear much quicker than other types of nozzles.
The ceramic nozzle wears the least.

31. This Sprayer Distribution Pattern
Shows Good Coverage Across The Boom

32. This Spray Pattern Shows Worn Nozzles ; Greater Spray Under Each Tip Will Occur

33. NOZZLE PATTERN Not every nozzle is created equal ! !
MAJOR TYPES )Standard Flat Fan )Extended-Range Flat Fan )Even Flat Fan )Twin Flat Fan )Flooding Fan Nozzles )Full Cone )Hollow Cone

34. FLAT FAN NOZZLE Jack of all trades Operating Pressure : 30 - 60 psi
Available in 65 , 80, and 110 degree angles
Overlapping is required for uniform application
A preferred nozzle for herbicide application

35. EXTENDED-RANGE FLAT FAN NOZZLE
Similar to Flat Fan but with wider pressure range psi.

36. EVEN - FLAT FAN NOZZLE Applies uniform amount across its spray width
Used in band applications
Pressure requirement of psi and available in 40 or 60 degree spray angles

37. TWIN-FLAT FAN NOZZLE
Nozzle will have two openings ; 60 degree separation
Increases penetration into crop canopy
30 to 60 psi

38. FULL CONE NOZZLE
Best for pre-plant incorporated herbicides at the psi range. Low pressure and large droplet size will reduce drift
This cone nozzle is used for high volume applications
40 inch spacing and nozzles need to be angled at 30 to 45 degrees from vertical to increase uniformity

39. HOLLOW CONE NOZZLE
Best suited for Postemergence herbicides. Can also do well for placement of insecticides, etc.
Fits well into low volume applications
Drop nozzle applications / psi

40. FLOODING FAN NOZZLE “FLOODJET”
Create a wide deflector type flat spray pattern
Larger orifice reduces clogging
10-40 psi range / 40” spacing

41. SPRAYER SPEED Inverse relationship between speed and application rate
As speed increases application rate decreases
To determine mph use the following formula : MPH = Distance Traveled (ft) x Time (sec.) x 88

42. SAMPLE PROBLEM
Determine the mph if a sprayer travels 130 ft. in 40 seconds.
MPH = x x 88
MPH = 7800/3520 = 2.2 mph

43. CALIBRATION TECHNIQUES
There are numerous methods used in calibrating sprayers. Several different techniques and formulas will be discussed in class

44. Calibration Tools

45. CALIBRATION: Method 1 Measure off known area
Fill sprayer with water to set level
Spray known area noting pressure and speed settings
Determine volume used
Set up an equality to solve for your application rate

46. CALIBRATION: Method 1 Assume area measured off is 50 feet by 60 feet
50 x 60 = 3000 sq ft.
The volume used was 4 gallons then the equality
is as follows …
4 gallons = x gallons
3,000 sq. ft ,560 sq. ft
X = 58 gallons per acre (GPA)

47. CALIBRATION FORMULAS : Method 2
GPA = x GPM ( of nozzle)
MPH x NW (nozzle spacing
in inches)
GPA = x GPM ( of sprayer)
MPH x BW ( boom width in feet)
Conversion Factors

48. CALIBRATION
While the sprayer is running determine the nozzle output or boom output by collecting the spray and measuring the volume.

49. SAMPLE PROBLEM Determine the GPA of a sprayer if given the following
information. The nozzle out put averages .25 GPM and they
are spaced at 30 inches. The sprayer will travel at 6 MPH.
Using this formula one can solve for GPA :
GPA = x GPM
MPH x NW
GPA = 5940 x .25
6 x 30
GPA = 8.25

50. SAMPLE PROBLEM Determine the GPA of a sprayer given the following
information :
The sprayer has 8 nozzles and each nozzle averages .5 GPM.
The boom width is 12 feet and will be traveling at 4 MPH.
GPM is for the entire sprayer
(8 nozzles). Therefore multiply 8
times .5 to get the sprayer out put of
4 GPM
GPA = 495 x GPM
MPH x BW
GPA = 495 x 4
4 x 12
GPA = 41.3 or round off to 41

51. Farmer Calibration On-Line at: http://annearundel. umd

52. Farmer Calibration

53. Farmer Calibration

54. DRY BROADCAST APPLICATION
Measure a Known Area
Weigh Product Before One Treats the Area and Note Spreader Setting
Reweigh After Application
Setup Equality

55. DRY BROADCAST APPLICATION
How much Insecto 5G will be applied per acre based on the following information
Spreader Setting L
Area for calibration is 50 ft by 80 ft : 80x50 = 4,000 sq. ft.
Amount of Insecto 5G placed in spreader was 90 lbs
Area is treated and Insecto 5G is reweighed at 85 lbs. Difference = 5 lbs
Set equality : 5 lbs = x , ,560
Solve for x : (4000) (x) = (5) x (43560)
X = 54.5 lbs will be applied per acre

56. COMPUTERIZATION Sprayer Control Systems
Adjust Pressure and Speed to Deliver Desirable GPA Rates
Pictures From Teejet Web Page