A system to assess the mass balance of spray applied to tree crop

The measurement of pesticide spray losses from air blast sprayers as they apply to tree crops is required to provide the industry with information on sprayer efficiency. Spray loss, however, is often difficult to measure using current standardized methods. Test procedures are often time consuming and too costly to be extensively used. To facilitate sampling of spray losses during application to tree crops, a device consisting of an adjustable metal frame and a grid has been developed. The grid support artificial targets. The frame stands in the vineyard or orchard over two adjacent rows, allowing the sprayer to pass below the structure, while applied a predetermined spray volume rate. Spray deposit on the collectors enables assessment of the amount of spray droplets dispersed in the atmosphere around the plant target. On one hand, the system aims to develop an alternative procedure to the presently proposed ISO methodology (DIS 22369.2) for classification of orchard/vineyard sprayers according to drift risk. On the other hand, it could facilitate the study of the spray mass balance discharged to target plants, ground and atmosphere, integrating ISO standard CD 25522 concerning field measurement of spray distribution in tree and bush crops. This article reports the first results related to the use of the device.