A model for the capture of aerially sprayed pesticide by barley

This paper sets out a novel method of modelling the capture of pesticide sp ray by a cereal crop. Firstly, the transport model, based upon that of Moke ba et al. (J. Wind Eng. Ind. Aerodyn. 67&68 (1997) 923-933), is described. This models the effect of turbulence on each individual spray droplet by us ing a random-walk model incorporating the Lagrangian variances and time-sca le of the air velocity. The crop model, which incorporates a realistic thre e-dimensional parameterization of the plant, is then detailed and the effec ts of the crop on the airflow are considered. Some useful applications to j ustify the added complexity of this new method are then outlined and a pers pective offered on the question of spray penetration of a crop canopy. Fina lly, an attempt is made at looking at the problem of drift at the scale of the field. (C) 2000 Elsevier Science Ltd. All rights reserved.