Self-propelled sprayer nozzle: main types and 10 hints to choose

Choosing the spray nozzles of the self-propelled sprayers strategically goes beyond technique — it’s a decision that impacts directly on the crop field yield. 

The spray nozzles are activated in the last step of the spraying system: it’s through them that the chemical reaches the target and eliminates pests and weeds.

In this article, you’ll see the main types and 10 hints to make the right decision to choose spray nozzles of your self-propelled sprayer, considering the product type, crop, operation speed, weather conditions, and others.

The importance when choosing the right spray nozzles

Choosing the sprayer nozzle directly interferes with the application efficiency, plant cover and drift risk. 

When the spray nozzles are worn-out or poorly corrected, they increase the chances of failures in weed control, pests, and weeds — in addition to cause product waste. According to the Stara experts’ team:

The spray nozzles are key parts in the agriculture application and minor issues could cause massive losses — either for product waste, poor coverage, drift, or weed control failures.

See the main advantages that a right choice could provide the farmer with:

• Uniform and precise coverage: the right spray nozzle distributes the droplets with uniformity, avoiding application failures and ensuring that all the plant receives the correct metering;
• Loss reduction by drift: compatible spray nozzles with the product type and weather conditions that minimize the droplet drift caused by the wind, protecting surrounding areas and avoiding losses;
• Phytosanitary control efficiency: droplets in the right size applied with the perfect jet pattern increase the efficiency in weed and pest control — and boost the yield potential.
• Savings and safety: when applying at the right metering, right target and minimum loss, the farmer reduces costs and protects the environment, in addition to protecting the operator’s health.

The Stara experts reinforce:

It’s no use having a good chemical product if it doesn’t reach the target. The spray nozzle ensures that.

Learn more: Self-propelled sprayer: how it actually works | Stara 

Types of spray nozzles for self-propelled machines

You should take into consideration the chemical product, the application target and the environment conditions when choosing the spray nozzle. Learn the main ones:

Flat fan spray nozzles

They are the most common in agriculture. They produce a jet-like fan, which is ideal for superficial coverage and row applications.

• Droplets: medium and fine;
• Shape: fan in a straight line;
• Common usage: post-emergent herbicides and applications in ranges;
• Advantage: excellent range uniformity, easy overlap adjustment;
• Limitation: subjected to more drift when there is wind.

Cone spray nozzles

They create a solid cone jet with good distribution in canopy areas.

• Droplets: fine;
• Shape: solid cone;
• Common usage: foliar fungicide and fertilizer;
• Advantage: high coverage and penetration in canopy (such as soybeans crop);
• Limitation: demanding caution with pressure to avoid too fine droplets.

Hollow cone spray nozzles

They form a ring-like jet with more concentration on the edges. They are recommended when the purpose is to reach the bottom of the leaves or hard-to-access areas.

• Droplets: too fine (high penetration);
• Shape: annular cone (hollow in the centre);
• Common usage: contact-acting insecticide, pest control under the leaves;
• Advantage: excellent plant penetration;
• Limitation: higher sensibility to drift, ideal for days with a slight wind.

Anti drift spray nozzles (Air Induction)

They mix the air to the liquid to create larger and heavier droplets, reducing the drift chance.

• Droplets: large with air bubbles;
• Shape: fan with air induction;
• Common usage: systemic-acting herbicide;
• Advantage: lower drift risk even under adverse conditions;
• Limitation: less uniform coverage in small targets.

Twin fan spray nozzles (Twin Fan)

They feature two opposite jets, which improves the coverage in vertical leaves or the higher structure of the plant.

• Droplets: average;
• Shape: two fans - forward and backwards;
• Common usage: fungicide and insecticide in crops such as corn and wheat;
• Advantage: higher efficient in taller crops, excellent side coverage;
• Limitation: could require fine adjustment in the pressure and in the boom height.

Comparative of the main types of spray nozzles

Ten tips to choose the perfect spray nozzle for a self-propelled machine

Check the following items to decide. Consider the factors and adapt the recommendations of our experts for your crop needs.

1. Choose the product to be applied

Choose whether herbicide, fungicide, insecticide, or foliar fertilizer will be applied. It directly impacts on the required chemical solution and ideal droplet pattern.

2. Check the product action mode

There are two main modes to be considered. The systemic-acting penetrates the plant and moves internally, absorbing larger droplets (anti-drift spray nozzles).

On the other hand, the contact-acting reach and require smaller droplets and good coverage (cone or fan spray nozzles).

3. Consider the environment conditions

Dry weather, high temperatures and constant wind increase the drift risk. For wind speeds above 10 km/h, choose anti-drift spray nozzles. When there is no wind, use fine droplet spray nozzles.

Example applied to the farmer routine

When there is constant wind above 10 km/h, the drift risk significantly increases. The most recommended is to choose anti-drift spray nozzles that produce larger and heavier droplets, less subjected to be taken by the wind. 

Under higher temperatures and low humidity, the issue becomes major as there is evaporation of the droplets even before they reach the target. 

In such situations, it is also recommended to use spray nozzles that produce coarser droplets. 

When there is no wind, or a slight wind and low temperature, you can use fine droplet spray nozzles, such as the hollow cone that provides excellent coverage and penetration, especially for contact-acting applications.

4. Learn the operation speed of the agricultural machine

The sprayer speed (ex: 20 km/h) directly affects the flow required in each spray nozzle. The higher the speed, the more flow is required.

5. Choose the chemical solution volume (L/ha) according to the product:

The chemical solution volume per hectare varies according to the product type to be applied. In general, use 50 L/ha for herbicides that require less coverage. 

Fungicides that require more contact-acting for the top of the plants, it is common to apply 100 L/ha. 

For the insecticides, especially when the target is in hard-to-access areas in the plant, they require higher volume — around 150 L/ha or more — to ensure an efficient coverage.

6. Calculate the flow per spray nozzles according to the technical formula:

 Q = (L × V × E) ÷ 600.  Where:

• Q = nozzle flow (L/min);
• L = volume per hectare (L/ha);
• V = speed (km/h);
• E = spacing between nozzles (cm).

7. Choose the spray nozzle type as your need

Take into consideration the jet pattern, droplet size and application target. If necessary, refer to the previous section about the most recommended spray nozzle types.

8. See the manufacturer table

It recommends the exact flow in different pressure types, the droplet type (fine, medium, coarse) and the recommendation per application type. The colors of the spray nozzles meet the ISO Standard and are easy to be identified.

9. Do a practical test before the operation

Assemble the spray nozzles on the sprayer booms and visual check the jet pattern. Use water-sensitive paper to assess the uniformity and assembly position between the spray nozzles.

10. Have regular preventive maintenance service

Assess the wear of the spray tips and the actual flow. If the deviation is above 10% from the nominal value, replace the spray nozzle immediately. This routine should take part in the preventive maintenance of the agricultural machines. It avoids failures that you can’t see and that impair the application efficiency.

How can the Stara spraying technologies optimize the usage of the spray nozzles?

In addition to the correct choice of the spray nozzle, the spraying performance is directly connected to the agricultural technology of the self-propelled machine. 

Models such as Imperador 3.0 and Imperador 4000 sprayers are factory-equipped with systems that monitor pressure, speed, and flow in real time, automatically adjusting the application to keep the correct metering under any operation condition.

The automatic control of the flow along with the different models of the Stara spray nozzles ensure precision even with different and climate types. 

The operator of the agricultural machines chooses the target-volume per hectare, and the system adjusts the pressure according to the agricultural machine speed, avoiding coverage failures and waste.

The compatibility between the Stara self-propelled sprayers and different spray nozzle types — fan, anti-drift, full cone, twin fan — also eases the application to the crop type and the plant development stage without the need of complex adaptations.

This set of technologies reduces the risk of errors, improves the operating efficiency, and prolongs the lifespan of the components, provided that the spray nozzles are often inspected and replaced according to technical recommendations.

Conclusion

The application efficiency of the chemicals starts in the end: in the spray nozzle. With a bunch of options in the market, understanding the technical characteristics, the application type and the operating conditions is the way to ensure high performance in the field.

The Stara self-propelled sprayers are developed with technologies that ease that choice — such as the automatic control of the flow, the operator support, and the compatibility with different types of spray nozzles.

Having the right spray nozzle, right metering and right adjustment, the result is yield, savings and more safety for your crop field.

Did you like the hints and want to find out the agricultural machine that best suits your crop field?

Stop by a Stara dealer and find the most suitable equipment to boost your crop production. Request a quotation.

 Contact our technicians