Unit 10 Applying the Correct Amount


  • Deciding How Much to Apply
  • Mixing, Loading, and Calibration Alternatives
  • Calibrating Your Equipment
  • Calibration Methods
  • Measure Accurately

Learning Objectives Unit 10 Applying the Correct Amount

After you complete your study of this unit, you should be able to:

  • Describe how to determine how much pesticide to apply.
  • Identify ways that application rate is expressed.
  • Explain why it is important to calibrate some equipment.
  • Describe how to figure, application rate.
  • Explain the importance of checking calibration often.
  • Explain which types of pesticides must be diluted before application.
  • Explain what information you must find in the pesticide labeling or in other recommendations before you can dilute the pesticide correctly.
  • Explain what information you must know about.your own situation before you can calculate how much of the dilute pesticide mixture to prepare.

Test Your Knowledge Unit 10 Applying the Correct Amount

Q. Why is it so important to apply the correct amount of pesticide to the target site?
A. If you apply too little pesticide, you may not fully control the pest. Overdosing may cause damage or injuries, leave illegal residues, and cause you to be fined or to be liable for damages.

Q. Where can you find out how much pesticide to apply?
A. From the "Directions for Use" section of the pesticide labeling, and from other sources, such as consultants, industry organizations, pest or pesticide specialists, Cooperative Extension agents, university specialists, or pesticide dealers.

Q. What are some of the ways that application rates may be stated?
A. Application rates may be stated as:

  1. Amount of formulation per unit of area or per unit of volume, such as pounds or gallons per acre, per square feet, or per cubic feet.
  2. Amount of formulation per volume of mixture, such as 3 tablespoons of product per 5 gallons of kerosene or 1 pint of product per 100 gallons of water.
  3. Amount of active ingredient per unit of area or per volume of mixture, such as 1 pint active ingredient per 1,000 square feet, or 1/2 pound active ingredient per 500 gallons of water.
  4. Percentage of the final dilution, such as 1/2 percent by volume or 1 percent by weight.

Q. Why is it important to calibrate some types of pesticide application equipment?
A. Many types of pesticide application equipment must be calibrated so that the correct amount of pesticide will be released to the target site.

Q. How do you calculate the application rate?
A. The amount of pesticide dispersed, divided by the distance covered, is the application rate.

Q. Why should you recheck equipment calibration frequently?
A. Clogging, corrosion, and wear may change the delivery rate, or the settings may gradually get out of adjustment.

Q. What pesticide formulations must be diluted before application?
A. You must dilute all formulations except those that are sold as ready-to-use products or those designed to be applied full strength.

Q. What information do you need to get from the pesticide labeling or other sources before you can dilute pesticides correctly?
A. Read the pesticide labeling or consult recommendations from other sources to find out what to use to dilute the formulation; how much to dilute the formulation; and how much of the dilute pesticide to apply per unit of area.

Q. What information do you need to know about your own situation before you can calculate how much pesticide and diluent to combine to achieve the correct amount of dilute pesticide mixture in your application equipment?
A. You must know how much your equipment holds when full or how much mixture you will need to complete the job; how much mixture your equipment applies per unit of area; and the size of the site you need to treat.

Additional Resources
Clemson University websites:

  1. Clemson University Department of Pesticide Regulation
  2. Clemson University Pesticide Information Program