WAC 16-230-640
Use restricted herbicides -- Eastern
Washington -- Weather and temperature conditions. Use
restricted herbicides shall not be applied on and after April
1 through October 31 of each year when there is a temperature
inversion; or throughout the year if weather conditions are
such that damage could result to adjacent and nearby towns,
susceptible crops and plantings through physical drift or
volatilization, or the temperature is 85°F. or above at the
point of application: Provided, That application at the rate
of fifty gallons or more per acre using nozzles having a
minimum orifice diameter of .072 inches shall be exempt from
the 85°F. temperature cutoff requirement: Provided further,
That when using the invert system, applications may continue
up to 95°F. with a maximum wind velocity of fifteen miles per
hour and with water carrier at twelve or more gallons per
acre.
[Statutory Authority: Chapters 17.21, 15.58, and 34.05 RCW. 07-11-041A, § 16-230-640, filed 5/9/07, effective 6/9/07. Statutory Authority: Chapters 15.58 and 17.21 RCW. 88-05-033
(Order 1965), § 16-230-640, filed 2/12/88; 87-09-015 (Order
1923), § 16-230-640, filed 4/6/87; 80-03-041 (Order 1680), §
16-230-640, filed 2/20/80.]