Downwind Deposition Of 2, 4-Dichlorophenoxyacetic Acid Herbicide (2,4-D) In Invert Emulsion

Abstract

ABSTRACT Deposits of 2,4-dichlorophenoxyacetic acid herbicide (2,4-D) from both pressure-atomized and Visko-Rhap invert emulsion equipment were measured on vertical plastic targets from the spray swath to 549 m (1800 ft) downwind. The quantity of 2,4-D deposited at 15 m downwind from a fixed-wing aircraft using the invert under windy conditions was 47% of that from the pressure-atomized spray. At 549 m, the deposit from the invert averaged 5% of that from the spray. Equations for predic-tion of deposition given distance from the spray swath were developed for both application methods. For this invert system, one half to one third of the required (Arkansas) 1609 nl (1 mi) spray buffer provided chemical deposition equivalent to that from the pressure-atomized spray. Deposition.fruit would be located.system performed reliably at a sustained harvesting rate of approximately 1.4 ha/day (3.4 acre/day), while indicating that a rate of 2 ha/day (5 acre/day) should be easily achievable. The system is operated by two workers and reduces conventional labor requirement by approximately 80-85%.