A System to Assess the Mass Balance of Spray Applied to Tree Crops

The measurement of pesticide spray losses from air blast sprayers as they apply to tree crops is required to providethe industry with information on sprayer efficiency. Spray loss, however, is often difficult to measure using currentstandardized methods. Test procedures are often time consuming and too costly to be extensively used. To facilitate samplingof spray losses during application to tree crops, a device consisting of an adjustable metal frame and a grid has beendeveloped. The grid supports artificial targets. The frame stands in the vineyard or orchard over two adjacent rows, allowingthe sprayer to pass below the structure, while applying a predetermined spray volume rate. Spray deposit on the collectorsenables assessment of the amount of spray droplets dispersed in the atmosphere around the plant target. On one hand, thesystem aims to develop an alternative procedure to the presently proposed ISO methodology (DIS 22369.2) for classificationof orchard/vineyard sprayers according to drift risk. On the other hand, it could facilitate the study of the spray mass balancedischarged to target plants, ground, and atmosphere, integrating ISO standard CD 22522 concerning field measurement ofspray distribution in tree and bush crops. This article reports the first experimental results related to the use of the device.