Comparison of Propiconazole and Mancozeb Applied Individually or Sequentially for Management of Fungal Brown Spot of Wild Rice. J. A. Percich, Associate Professor, Department of Plant Pathology, University of Minnesota, St. Paul 55108. C. M. Huot, Associate Scientist, Department of Plant Pathology, University of Minnesota, St. Paul 55108. Plant Dis. 73:257-259. Accepted for publication 4 November 1988. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0257.

Propiconazole and mancozeb applied at 0.24 and 1.12 kg a.i./ha, respectively, to wild rice (Zizania palustris) plants inoculated with Bipolaris oryzae resulted in lower yields and higher disease severity ratings than fungicide-treated noninoculated controls. Inoculated plants receiving one application of propiconazole followed by two of mancozeb (at boot and heading) had higher yields than other inoculated plants, but the yields did not differ significantly (P = 0.05) from those of noninoculated plants receiving five applications of mancozeb (at 7-day intervals, beginning at boot). Inoculated plants receiving one application of propiconazole plus two of mancozeb averaged 24% higher yields than inoculated plants receiving one application of propiconazole at either boot or heading. Propiconazole and mancozeb, individually or sequentially, resulted in significant (P = 0.05) increases in yield (38–120%) compared with the inoculated but nontreated controls.

Keyword(s): Cochliobolus miyabeanus.