Off target ground deposits from spraying a semi-dwarf orchard

Ground deposits in the orchard and downwind were measured over the entire growing season when fungicide sprays were applied with an air-blast sprayer on semi-dwarf pears and apples. Deposits on the soil in the orchard were monitored by means of round cellulose strips, placed in petri-dishes, in and between the tree rows. Downwind deposits were measured by means of cellulose strips placed on the ground at 5-40 m from the outer tree row. Deposits between the tree rows were significantly greater than the ground deposits in the rows, and decreased with greater distance downwind from the orchard. Deposits at 5 m downwind were comparable with the soil residues found in the tree rows. The highest downwind ground deposits were measured when the trees did not have full foliage (during blossom). (C) 2000 Elsevier Science Ltd. All rights reserved.