APPLICATOR EXPOSURE AND DRIFT PROBLEMS OF CYANOPHOS INSECTICIDE APPLIED ON COTTON FIELD USING TWO APPLICATION METHODS

Two sprays of cyanophos were applied on cotton plants adjacent to maize field by two methods of application, i.e. micron ULVA and a motorized knapsack mistblower. Operator exposure during application, drift residues on maize plants and the toxicity of these residues on fish and honeybees were estimated. Fish and bees were located on the ground of maize field at different distances from the edge of the cotton field. Dermal exposure was determined by measuring cyanophos on pieces of clothing fitted to applicator overall within the time specified for application. Results show that the higher level of deposition of the insecticide on the total area of all cloth patches fitted on different body regions was observed for the micron ULVA (total deposition for the two sprays was 11.8 mg within exposure time of 9.5 min versus 3.82 mg for the mistblower at the same exposure time). Deposition on different body organs could be arranged descendingly as follows: hands legs knees chest elbows or shoulders. Deposition was more in 1st spray than in 2nd one, mainly due to the difference of wind speed. At the 1st spray, distances traveled by cyanophos residues were 24 and 33 m when using the mistblower and micron ULVA, respectively. At these distances, the corresponding values of mean deposits were 16.5, 11.6 μg/kg of maize leaves, respectively. At 2nd spray (lower wind velocity) the distances were 18 and 24 m corresponding to 19.3 and 10.6 μg/kg maize leaves, respectively. Drift of cyanophos released by each of the tested equipment caused 100% mortality of fish and honeybees placed at the distances 3 and 6 m, respectively. Zero mortality for both organisms were observed at distances 18 and 30 m for the mistblower and micron ULVA, respectively. It is obvious that levels of dermal exposure or drift to non-target sites were higher for micron ULVA than for the mistblower. These levels were markedly affected by wind speed.