(1) Except as otherwise authorized in this subchapter, no city, county, or other political subdivision of the state shall adopt any ordinance, rule, or regulation regarding the registration, labeling, distribution, sale, handling, use, application, transportation, or disposal of pesticides.
(2) This section shall not affect the validity of any ordinance, rule, or regulation regarding the registration, labeling, distribution, sale, handling, use, application, transportation, or disposal of pesticides adopted before March 1, 1993.