VIEW ARTICLE

Effect of Pesticides on Growth and Sclerotial Production of Sclerotium rolfsii. G. A. Bozarth, Postdoctoral Fellow, Department of Plant Pathology, University of Missouri, Columbia 65201; B. G. Tweedy, Associate Professor, Department of Plant Pathology, University of Missouri, Columbia 65201. Phytopathology 61:1140-1142. Accepted for publication 1 April 1971. DOI: 10.1094/Phyto-61-1140.

The effect of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine), 1,1-dimethyl-3-(α,α,α,-trifluoro-m-tolyl) urea (fluometuron), 3-(p-bromophenyl)-1-methoxy-1-methylurea (metobromuron), α,α,α,-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin), and thiram on mycelial growth and production of sclerotia by Sclerotium rolfsii was investigated. At 50 µg/ml, thiram completely inhibited mycelial growth and inhibition by the herbicides ranged from 26-75%, with fluometuron being the most inhibitory. All herbicides inhibited numbers of sclerotia produced, with fluometuron being the most inhibitory (83% at 50 µg/ml). Sclerotia produced on herbicide-treated medium were larger than those produced on control medium. The weights per sclerotium (expressed as per cent of control) of sclerotia produced on media containing 50 µg/ml pesticide were: fluometuron 223, atrazine 189, trifluralin 179, metobromuron 165, and thiram 85.