3.4. Environmental fate: drift along field boundaries
The drift measurements along field margins show a rapid
decrease (of more than 85% on average) in drift, expressed
as a percentage of the applied dosage per unit area, with
increasing distance from the knapsack sprayer up to 0.5m
outside the treated field (Fig. 1). Beyond 0.5m the amount
of pesticide drift decreases at a lower rate reaching, on
average, a minimum level of about 2% of the within-field
dosage between 1.5 and 2.0m from the field boundary.
During most of the experiments the wind speed was 0ms1.
The highest wind speed of 3ms1 was recorded during only
one experiment.