Key aspects to reduce herbicide drift

Among the basic principles of sustainable agriculture, the use of agricultural pesticides stands out through the application of inputs in a rational, intelligent and effective way. Some factors can become challenging for the producer in the field, so he must be aware of correct management. Drift is an example that can disrupt the spraying stage, which is so important for crop productivity and yield.

Drift occurs due to volatilization of active ingredients or physical displacement of droplets. Physical drift is the movement of droplets away from the application area, while vapor drift is the movement of the product after the active ingredient is converted from its gaseous form. When it happens, it can cause damage to susceptible areas around applications and reduce the dose applied in the treatment, reducing effectiveness and inducing the selection of resistant species. Furthermore, drift can generate environmental contamination and the appearance of illegal product residues in neighboring crops.

Considering the main factors causing drift, here are some important tips for reducing the risk:

1. Follow the product leaflet to ensure correct and safe use, with minimal risk to the environment. Many drift complaints involve applications that do not comply with the product labels;

2. Select non-volatile or low volatility active ingredients or formulations;

3. If recommended, use adjuvants in accordance with the package inserts. This will result in better effectiveness and generally less potential for drift;

4. Use nozzles with larger orifices and lower spray pressure, preferably models with air induction, producing larger drops with less drift potential.

5. Use the tips at an angle of 110o or greater, keeping the bar stable, level and with a maximum height of 50 cm above the targets;

6. Drift is smaller when the average wind speed is between 3 and 10 km/h. Do not spray when there is no wind, situations where there may be thermal inversion or convective currents (these meteorological phenomena cause droplets to float). Do not spray when the wind is at high speeds (above 10 km/h, on average), or when it is blowing towards sensitive crops, gardens, homes, livestock, water sources or other sensitive areas;

7. When possible, use lower application speeds. As application speed increases, unintended effects occur on other application parameters that can increase drift.