Guide to spraying pesticides with drones to reduce costs by 40%

• Reasons and goals for using drones in pesticide spraying
• Preparation: tools, materials, and knowledge
• Six-step drone spraying process
• Common mistakes and safety warnings
• How to measure spraying effectiveness
• Should you invest in drone spraying technology?
• FAQs about drone pesticide spraying

Reasons and goals for using drones in pesticide spraying

Traditional manual spraying requires significant labor, leads to uneven chemical distribution, and wastes both pesticides and water. Drone spraying solves these inefficiencies by automating the process, improving coverage, and protecting farmers’ health.

Reasons for adoption:

• Labor and time efficiency: Manual spraying is slow, labor-intensive, and prone to uneven application.
• Reduced chemical and water loss: Wind, canopy cover, and runoff reduce efficiency in manual methods.
• Safety and sustainability: Drones eliminate direct human exposure to toxic chemicals.
• Scalability: Ideal for large or fragmented farmland requiring rapid coverage.

Goals of drone spraying:

• Achieve even, consistent coverage across fields.
• Cut pesticide use by 30–50% compared to manual methods.
• Reduce labor and spraying time (one drone can replace several workers).
• Improve crop health and yields through precise pest control.
• Establish safe, compliant UAV spraying operations.

Common causes of failure:

• Using the wrong equipment or improper flight planning.
• Incorrect pesticide type or concentration.
• Overlapping or missing flight routes.
• Poor operator training or ignoring UAV safety standards.

Preparation: tools, materials, and knowledge

Before operating pesticide-spraying drones, proper preparation ensures safety, precision, and cost efficiency.

Main equipment:

• Agricultural UAVs such as DJI Agras T25, T40, or T50.
• Spray tanks (20–40 L) with fine-mist or centrifugal nozzles.
• Batteries, chargers, generators, and spare parts.
• Flight planning software and obstacle-avoidance sensors (radar, ToF).
• Technical manuals and operational guides.

Materials and chemicals:

• Pesticides suitable for drone application (avoid powder or heavy oil-based formulas).
• Clean, neutral water for mixing.
• Measuring tools, concentration testers, and PPE (gloves, goggles, masks).

Required skills:

• Knowledge of crop types, pest stages, and weather conditions.
• Proper chemical mixing procedures (less water than manual spraying).
• Certified UAV operation training and understanding of local airspace laws.
• Ability to plan flight routes, speed, and spray volume.

Legal and environmental compliance:

• Register UAVs with aviation/agricultural authorities if required.
• Obtain permits for aerial pesticide application.
• Keep pesticide residue and flight logs for traceability.
• Ensure flight safety, insurance, and environmental protection.

Six-step drone spraying process

Step 1. Map the area and plan flight routes

• Identify the exact spraying area, crop type, and pest density.
• Use satellite maps or drone reconnaissance to create routes.
• Avoid overlap or missed zones to prevent chemical waste.

Step 2. Inspect the drone and equipment

• Ensure batteries ≥ 80%, sensors functional, and no leaks or clogs.
• Check GPS, obstacle sensors, and weather (wind < 5 m/s).

Step 3. Mix pesticides correctly

• Use smaller water ratios suited for drone spraying.
• Avoid powders and thick emulsions.
• Mix in order: solids → viscous → liquids → foliar nutrients.

Step 4. Configure flight and spray parameters

• Set proper height (2–3 m above canopy) and speed (4–6 m/s).
• Adjust spray flow rate to crop type and density.

Step 5. Monitor flight and adjust as needed

• Watch FPV feed to ensure uniform coverage.
• Pause or redirect if wind shifts or weather changes.

Step 6. Land safely and clean equipment

• Rinse tanks and nozzles with clean water.
• Record data: area sprayed, pesticide used, and total cost.

Common mistakes and safety warnings

Frequent mistakes:

• Mixing incorrect pesticide concentrations.
• Using incompatible chemicals that clog nozzles.
• Flying at wrong altitudes or in strong winds.
• Skipping post-spray cleaning.
• Failing to record usage data.

Safety warnings:

• Only certified UAV operators may conduct spraying flights.
• Never fly near residential areas or schools.
• Follow labeled dosage and re-entry intervals.
• Avoid flying in fog or darkness.

Recommendations:

• Always check weather forecasts (wind ≤ 5 m/s).
• Conduct small test flights before large-scale spraying.
• Adjust schedules based on crop stages and pest conditions.
• Focus on efficiency factors (less pesticide, fewer workers, faster coverage).

How to measure spraying effectiveness

Track these key indicators to confirm real savings and performance:

Metric	Before drone spraying	After drone spraying
Pesticide use per ha	15 L	8–10 L (↓ 30–50%)
Time to spray 10 ha	2–3 days	1–2 hours
Labor required	50 man-hours	10 man-hours
Total cost	100%	~60% (↓ ≈ 40%)
Crop loss due to pests	~10%	< 5%

Example:

A 20 ha orchard required 10 workers for 3 days using 300 L of pesticide (~₫20 million total). With a drone, one operator completed spraying in 30 minutes using 150 L (~₫12 million), saving ~40% overall.

Should you invest in drone spraying technology?

1. Large farms (> 50 ha): High initial cost but quick ROI due to frequent spraying needs.

→ Recommendation: Invest in your own drones or hire professional pilots regularly.

2. Medium farms (10–50 ha): Shared or cooperative ownership is cost-efficient.

→ Recommendation: Rent or co-own drones with local cooperatives.

3. Small farms (< 10 ha): Investment may not be cost-effective.

→ Recommendation: Use rental services when needed.

4. Complex terrain: UAVs are ideal for steep or uneven fields.

→ Recommendation: Choose drones with strong obstacle-avoidance systems.

5. Cost reduction and quality goals:

→ If your goal is to save ~40% and improve product quality, drone spraying is a suitable investment.

Additional tips:

• Estimate payback time (typically 1–3 years for 20 ha).
• Train qualified operators and maintain your equipment regularly.
• Consider partnerships with cooperatives for shared costs.

FAQs about drone pesticide spraying

Does drone spraying affect bees and beneficial insects?

Yes, if non-selective chemicals are used. Prefer biological pesticides and spray early morning or late evening.

Can drones be used in organic farming?

Yes, as long as only certified biological pesticides are applied and cross-contamination is avoided.

How much does drone spraying service cost?

Typically ₫180,000–₫300,000 per hectare per application (excluding pesticide cost).

How often should drones be maintained?

Inspect and clean after every 5–10 flight hours; perform major maintenance every 100 hours.

Can pesticides be sprayed at night?

Not recommended. Poor visibility increases risk; daylight conditions ensure safer, more precise operations.