Determining Amount Of Chemicals Required - Cushman Spraytek DS175 Safety & Operation Manual

6.9

DETERMINING AMOUNT OF CHEMICALS REQUIRED____________________________

To determine the amount of chemicals to add to the spray
tank, you need to know:
• The recommended
chemical. This information is given on the chemical
label. The rate will be listed as pounds per acre (or
pounds of active ingredient) for wettable powders
and pints, quarts, or gallons per acre for liquids.
• The capacity of the tank. The Spraytek is equipped
with a 175 gallon spray tank.
• The calibrated output of the sprayer.
Example 1, Dry Formulation:
A carbaryl recommendation calls for 2 pounds of active
ingredient (a.i.) per acre. You have purchased Sevin (80-
percent wettable powder). Your sprayer has a 175 gallon
tank and is calibrated to apply 20 gallons per acre. How
much Sevin should be added to the spray tank?
1. Determine the number of acres you can spray with
each tankful
• Tank Capacity/Spray Rate = 175/20 = 8.75 Acres
2. Determine the pounds of pesticide product needed
per acre. Because only 80% of the Sevin in the bag
is an active ingredient, you will have to add more
than two pounds of the product to each "acre's
worth" of water in your tank.
Divide the percentage of active ingredient (80%) into
the total (100%).
• 100/80 = 1.25
Multiply the result times the application rate.
• 2 lb/acre x 1.25 = 2.5 lb. Sevin per acre
3. Determine the amount of pesticide to add to each
tankful. With each tankful you will cover
(Step 1), and you want 2.5 lbs. of product per acre
(Step 2).
• 8.75 acres x 2.5 lb. sevin per acre = 21.875 lb.
To apply the recommended application rate, you will need
to add 21.875 lb. of Sevin for each full 175 gallon tankful.
application rate of
15 acres
SPRAYER OPERATION
Example 2, Liquid Formulation:
A trichlorfon recommendation calls for 1 pound of active
the ingredient (a.i.) per acre. You have purchased Dylox 4E
(4 pounds per gallon formulation). Your sprayer has a 175
gallon tank and is calibrated at 25 gallons per acre. How
much Dylox should you add to the spray tank?
1. Determine the number of acres you can spray with
each tankful
• Tank Capacity/Spray Rate = 175/25 = 7 Acres
2. Determine the amount of product needed per acre.
Divide the percentage of active ingredient (1 lb) into
the concentration of the formula (4 lb / Gallon).
• 1 lb/4 lb per gallon = 0.25 Gallon per acre
3. Determine the amount of pesticide to add to each
tankful. With each tankful you will cover 11.66 acres
(Step 1), and you want 0.25 Gallons of product per
acre (Step 2).
• 7 acres x 0.25 Gallon Dylox per acre = 1.75
Gallons
To apply the recommended application rate, you will need
to add 1.75 Gallons of Dylox for each full 175 gallon
tankful.
Adjuvants:
The chemical manufacturer may recommend that you
add a small amount of an adjuvant (spreader-sticker,
surfactant, etc.) in addition to the regular chemical. This
recommendation
concentration."
If you use an adjuvant at a 1/2% concentration by
volume, how much should you add to a 175 gallon tank.
Convert percentage into decimal form
• 1/2% = 0.005
Multiply tank capacity by decimal amount of adjuvant
• 175 Gallons x 0.005 = 0.875 Gallons adjuvant
is often given as
6
"percent
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