VIEW ARTICLE

Phoma glomerata, a New Pathogen of Wheat and Triticales, Cultivar Resistance Related to Wet Period. R. M. Hosford, Jr., Associate Professor, Department of Plant Pathology, North Dakota State University, Fargo, North Dakota 58102; Phytopathology 65:1236-1239. Accepted for publication 2 June 1975. DOI: 10.1094/Phyto-65-1236.

Phoma glomerata caused no leaf spotting on any of the tested Gramineae following a postinoculation wet (mist) period of 6 or 12 hours. Following a wet period of 24 hours it caused severe leaf spotting on spring wheat cultivars Red River 68, Taichung 2, Ring, Inrat 69, and Zafrani and on a triticale with Armadillo parentage. It caused slight spotting on Waldron spring wheat and Hercules durum. Only after a postinoculation wet period of 48 hours did it cause severe spotting on Waldron and moderate spotting on Hercules. The triticales Fasgro 418, Fasgro 419, NDT 24, and 209 were not spotted. After 72 hours in mist the fungus caused severe spotting on Tobari 66 spring wheat and Leeds durum, and slight spotting on Marquis spring wheat. It did not cause spotting on Chris, C306, ND495, and ND487 spring wheats, Wells durum, Larker barley, Caribou rye, or Lodi oats. Apparently the fungus required a postinoculation wet period to cause leaf spotting, and expression of susceptibility or resistance to leaf spotting was associated with the duration of the wet period.