WAC 16-230-180
WAC 16-230-180. Weather and evening cutoff requirements for desiccants and defoliants
The following requirements apply to the entire area under order as listed in WAC 16-230-150 :
(1) Weather conditions: Use restricted desiccants and defoliants shall not be applied when there is a temperature inversion, or if wind or weather conditions are such that damage could result to susceptible crops or ornamentals: Provided, That aircraft applications of Paraquat shall be prohibited until the temperature inversion ceiling at the site of application is 1,000 feet or greater. Aircraft must be equipped with thermometers to detect the height of the inversion.
(2) Evening cutoff: All applications of use restricted desiccants and defoliants are prohibited from three hours prior to sunset to one hour after sunrise the following morning: Provided, That ground applications in Area 2 of Walla Walla County may begin at sunrise: Provided further, That ground applications may be allowed at other times by obtaining a written permit from the department.