This paper concerns the development of research methodologies for pesticide application with an air assisted sprayer on vines within the scope of improving treatment efficiency and minimising risk level. The objectives are to develop numerical models to calculate the flow sprayed within the canopy and the amount of pesticide captured by the foliage. Measurements were set-up in a vineyard with a fluorescent tracer. A volume of vegetation was referenced in position and harvested to measure leaves surfaces and deposit. Other measurements, in laboratory, gave a description of the physical characteristics of the spray (air velocities, droplet size and velocities) for the sprayer used in field tests. To understand the behaviour of an airflow in presence of vegetation, air velocities were also measured in front of and behind an artificial plant row. Numerical models were developed using the Computational Fluid Dynamic software CFX 4.3. It was proposed to modelise the influence of the vegetation on wind velocities by the use of a resistant force added to the momentum equation. Tests on artificial plants allowed checking relations commonly used in literature between this resistant force and Leaf Area Density. These relations were then used to compute flow velocities for the vineyard test conditions. Deposits were simulated as the product`s mass fraction diminution in the air through the canopy. The mass fraction was represented by a scalar in the advection-diffusion equation whereas mass fraction reduction was modelised by a negative source term in the right hand side of the equation. In this work, the measured and computed airflow and deposit were compared.