Why is choosing the right spray nozzle important?
There are dozens of spray nozzle types available in different sizes, capacities, and materials. Confused? Don't be. Each nozzle is specifically designed to perform based on what you're spraying, when you're spraying, and how you're spraying
Nozzle Basics
Choosing the wrong spray nozzle can be a costly mistake.
Improper nozzle selection can be expensive if re-spraying is required, performance is reduced, or legal issues arise as a result of chemical drift. Take a few minutes to review your spraying requirements, and be prepared to have multiple nozzle sets on hand to meet your needs.
Spray nozzles are highly engineered, precision components.
Even a spray nozzle with only 10% wear may not give you the coverage and performance you require. The cost of replacing nozzles is minor compared to the consequences of poor spraying.
The spray nozzle you select will determine:
- Amount of chemical applied to an area
- Uniformity of the application
- Coverage of the chemical on the target surface
- Amount of potential drift
Three common types of spray nozzles include:
|
Flat Fan Used for broadcast and band spraying |
Cone Used for spot, directed and air assisted spraying |
Streaming Used for application of liquid fertilizer |
Droplet size is a key factor in nozzle selection.
The ASABE (American Society of Agricultural and Biological Engineers) S572.1 standard uses eight droplet classifications ranging from extremely fine to extremely coarse. Keep in mind that droplet size decreases as your sprayer pressure increases.
- Fine droplet sizes are used for contact fungicides, insecticides, or herbicides that require adequate retention on leaves.
- Medium droplet sizes are the most widely used and are typically suitable for systemic herbicides, insecticides, and fungicides.
- Coarse droplet sizes are used with systemic, residual, and soil-applied herbicides or to minimize spray drift.
VMD = Volume Median Diameter, in microns
Retention = Retention on Difficult to Wet Leaves
How to Identify Spray Nozzles
Nozzles have markings that will identify their performance specifications, including spray angle, flow rate and material. The color will also identify its flow rate at 40 psi. Red nozzles, for example, have a flow rate of 0.4 gallons per minute at 40 psi. These colors are different than the ones used to classify droplet size.
Read the pesticide label to determine the type of nozzle, its application rate, required droplet size, nozzle spacing and environmental restrictions.
How are you spraying?
Different types of nozzles are available for broadcast, banded, directed, or mechanical air-assisted spraying.
What is your tolerance to drift?
If your application could drift away from its target, you may need to consider low-drift spray nozzles.
Tips to control drift
- Reduce pressure to increase droplet size
- Use drift-reducing nozzles or larger capacity nozzles that produce larger spray droplets
- Lower boom height
- Pay attention to weather conditions and adjust application methods accordingly
What is the weight of the spray solution?
Nozzle specifications are based on water, so you may need to use a conversion factor if spraying something heavier or lighter.
What is the pressure range of the sprayer?
Selecting a nozzle in the middle of your sprayer's operating range will allow you to adjust the speed if necessary.
What is the nozzle spacing on the boom?
Manufacturers recommend optimal nozzle spacing for each nozzle type and spray angle. The most common spacing is 20" and 30".
What is the boom height?
Lower boom heights reduce drift and improve coverage. 110° nozzles can typically be used at lower boom heights than 80° nozzles.
What is your sprayer speed?
You'll get done spraying faster at higher speeds, but spray drift and canopy penetration improve at lower speeds.
Which nozzle material is best
Nozzle material will depend on the chemical being sprayed and your budget. Materials such as ceramic may be more expensive initially, but cost less in the long run because they wear longer. Never mix different nozzles or materials on your boom.
- Brass is the least durable nozzle material
- Plastic lasts two to six times longer than brass
- Stainless steel lasts four to six times longer than brass
- Ceramic lasts 20 to 50 times longer than brass
Nozzle Selection Guide
Once you pick a nozzle from Gemplers' selection, use its application table to choose a color. Don't see the nozzle you need? Give us a call, and we'll help you find it.
Herbicides
Fungicides
Insecticides
Drift Management
G = Good, VG = Very Good, E = Excellent
To learn more about sprayers, visit one of our helpful buying guides here.
