Suchergebnisse

Abstract
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.

Biocidal and plant protection products belong to the group of pesticides and serve to protect humans, animals and materials against pests and vermin. On the German market, most of the biocidal products have not yet fully been evaluated under the Biocidal Products Regulation 528/2012 due to transitional regulations, so there is still very little knowledge about the way in which biocidal products are used. The goal of this study was to identify and to investigate the areas with high drift potential. It turns out, that the areas with the highest drift potentials are the control of oak processionary moth (OPM) with sprayers and the control of flying and crawling insects in the surrounding of buildings with knapsack sprayers. Experimental results show, that in all applications the drift decreased exponentially with the distance from the treated area. The highest drift values were measured using cannon sprayers at the forest edge, slightly lower drift values in the avenue and considerably lower drift values when a solitary tree was treated. Using a helicopter, lower basic drift values of 50% were observed, if a nozzle with taller drops was used. These first results show that it is likely that biocidal products drift into non-target areas, leading to potential risks for non-target organisms. However, the results show possibilities to reduce basic drift values by choosing the technology least prone to drift. To measure the drift during the control of crawling insects on house walls, first trials were conducted. Independent of the wind direction, the measured drift directly in front of the treated area was very low. In the lateral distance to the treated area, the drift was lower with parallel than with orthogonal wind direction. In general, it is important to evaluate the equipment used to apply biocidal products.