High-clearance Tractor Research Articles

Worker exposure to paraquat and diquat.

Exposure of workers applying paraquat to fields of tomatoes and citrus, and diquat to waterways containing water hyacinths and hydrilla, was monitored with dermal α-cellulose pads attached at each of ten body locations and with personal air monitors. Estimated total body exposure for tomato applicators was apparently influenced by tractor type. Exposure levels from highest to lowest were: open tractor > enclosed cab tractor ⩾ high-clearance tractor. Citrus applicators' exposure to paraquat averaged 28.5 mg/hr and 12.2 mg/hr, with tank concentrations of 0.11% and 0.07%, respectively. Diquat applicators received minimal exposure. Respiratory exposure was <0.1% of the total body exposure in all experiments. Urine samples collected periodically for all workers were, with one exception, without detectable pesticide contamination. Use of disposable coveralls and regularly washed impermeable gloves should effectively reduce exposure.

Saturation Spraying of Blueberries with Partial Spray Recovery

ABSTRACT Ahigh-pressure high-volume sprayer with provision for recapturing and recycling undeposited spray was mounted on a high-clearance tractor and used to apply wetting sprays to blueberry bushes for blueberry bud mite (Acalitus vaccinii, Keifer) control. Approximately 40% of the nozzle output was recycled when nozzle discharge was providing nominal application rates of 306 L/ha at pressures of 690 to 2758 kPa and a ground speed of 4.22 km/h. The spray zone is partially enclosed, resulting in more complete coverage of the bushes. Airborne drift is substantially decreased.