Effects of Fungicides and Cultivar Genotypes on Populations of Septoria spp. on Spring Wheat in Minnesota. L. G. Haugen, Former Graduate Research Assistant, Department of Plant Pathology, University of Minnesota, St. Paul 55108. Roy D. Wilcoxson, Professor, and J. S. Baumer, Former Assistant Professor, Department of Plant Pathology, University of Minnesota, St. Paul 55108. Plant Dis. 69:162-163. Accepted for publication 13 August 1984. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-162.

Interactions between Septoria spp., spring wheat (Triticum aestivum) cultivars, and fungicides were studied at three locations in Minnesota in 1979 and 1980. Populations of Septoria spp. were estimated from numbers of pycnidiospores produced on primary tillers. The predominant species was S. nodorum followed by S. avenae f. sp. triticea; S. tritici was not found. Fungicide applications greatly reduced populations of both species across all cultivars and locations. Cultivar effects were generally small and varied with the year and Septoria spp. involved. Location effects were not significant.

Keyword(s): fenapanil, mancozeb, thiabendazole.