Skip to main content

Crop and Pest Management Guidelines

A Cornell Cooperative Extension Publication
Skip Navigation LinksHome > Cornell Guidelines > 2024 Grapes Table of Contents > 7 Sprayer Technology > 7.6 Selecting Nozzles from the Nozzle Catalogue –Boom Sprayers
Page Contents
44087

7.6 Selecting Nozzles from the Nozzle Catalogue -Boom Sprayers

Step 1. Calculate the required nozzle output.

Formula: GPM =

GPA X mph X nozzle spacing

5940 (constant)

Example: GPM =

20 X 4 X 20

=

1600

= 0.27 GPM

5940

5940

Consider forward speed e.g. 4 mph, if too high: boom bounce and boom yaw

Consider pressure, too high: may lead to drift, too low: may lead to droplet bounce

Example 1 - Using a Spraying Systems catalogue #49A, page 10

Look at the columns headed GPA at 20" nozzle spacing

Select the 4 mph column

Look down the column until you see a figure close to 20 gpa, then look to the left to find the operating pressure

For example:

  • Select nozzle XR8003VS or XR11003VS at 30psi to give 19.3 gpa
  • Select nozzle XR8004VS or XR11004VS at 20psi to give 21 gpa

Select the appropriate nozzle.

Example 2 - Using a Spraying Systems catalogue #49A, page 10

Look at column headed: Capacity of 1 nozzle in GPM

Read down column

  • Select nozzle XR8003VS or XR11003VS at 30 psi to give 0.26 GPM or
  • Select nozzle XR8004VS or XR11004VS at 20 psi to give 0.28GPM

44088

7.6.1 Selecting a Nozzle to Give Desired Spray Quality

Example using a Spraying Systems catalogue #49A, page 161.

In the previous exercise we considered selecting:

  • Nozzle XR8003VS or XR11003VS at 30 psi to give 0.26 GPM or
  • Nozzle XR8004VS or XR11004VS at 20 psi to give 0.28 GPM

Using the table in the next column, you can see:

  • An XR8003VS at 30 psi gives a medium spray quality
  • An XR8004VS at 20 psi gives a coarse spray quality but note:
  • An XR11003VS at 30 psi gives a fine spray quality
  • An XR11004VS at 20 psi gives a medium spray quality

Spray classification and target

1. Fine sprays can produce enhanced retention on the target and may be used for foliar acting weed control and cotyledon-stage weed control.

Careful attention must be paid to weather conditions: do not use a fine spray for pesticides labeled toxic, or when drift may cause problems near susceptible or sensitive areas.

2. Medium sprays when the leaf is the target.

3. Coarse sprays have a low risk of drift but should be used only where recommended as a lot of spray is wasted as the larger droplets bounce off the leaves.