Effect of Herbicides on the Growth ofChlorellaandBacillususing the Paper Disc Method

Abstract

Twenty herbicides were tested for activity in a paper disc agar bioassay. The growth ofChlorella pyrenoidosaChick was inhibited by dinoseb (2-sec-butyl-4,6-dinitrophenol), diquat [6,7-dihydropyrido(1,2-a:2′,1′-c)pyrazinediium ion], paraquat (1,1′-dimetnyl-4,4′-bipyridinium ion), 3′,4′-dichloro-2-methylvaleranilide, propachlor (2-chloro-N-isopropylacetanilide), and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea]. The growth ofBacillus subtilisCohn was inhibited by dinoseb, diquat, paraquat, and 3′,4′-dichloro-2-methylvaleranilide. This assay usingC. pyrenoidosaorB. subtilisoffers a convenient means for the testing of herbicides.