Farmers must return banned agri-chemicals by August 29 By THE NATION     The ban on paraquat and chlorpyrifos will take effect on June 1 and farmers must return the banned agri-chemicals in their possession to sellers within 90 days, Government Deputy Spokesperson Traisulee Traisoranakul said on Saturday (May 30).     “The Ministry of Industry published the list of banned toxic chemicals [sixth edition] in the Royal Gazette on May 19 to be effective from J