Possibilities to reduce drift by 75 percent in biocidal applications of insecticides with cannon sprayers

Background

Insecticides are applied on a large scale in the environment to control the oak processionary moth (Thaumetopoea processionea) for the protection of human health. Drift of the insecticides to non-target areas is a risk for the surrounding biodiversity. Since the habitats of the caterpillars are usually restricted to the treetops, the sprayers used to apply biocidal products must be able to transport the droplets over longer distances. Therefore, cannon sprayers are often used. In this study, spray drift in an oak avenue from a cannon sprayer with hydraulic atomisation was measured with two different nozzles. The aim of this study is to compare spray drift when using a cannon sprayer with different drift-reducing nozzles with cannon sprayers with pneumatic atomisation to find options to reduce drift to non-target areas.

Results

The results show that compared to the basic drift values for biocidal products using a cannon sprayer with pneumatic atomisation, a cannon sprayer with ID-120-05 POM nozzles achieves a drift reduction of 75% and a classification in this reduction class. No drift reduction could be determined with a cannon sprayer with AirMix 110-05 nozzles.

Conclusions

Better knowledge of drift of biocidal products is of utmost urgency in order to be able to compare and classify the currently used technologies. When using a cannon sprayer, this study shows that specific drift values are recommended based on the type of atomisation, as droplet size is an important factor in reducing drift. By choosing the technology with the highest drift reduction, the drift of biocidal products into the environment can be minimised by 75%, thus ensuring a much better protection of the environment.