Wheat Leaf Rust in North Dakota During 1982-1984. G. D. Statler, Professor, Agricultural Research Service, U.S. Department of Agriculture, North Dakota State University, Fargo 58105. J. D. Miller, Research Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, and D. C. Hirsch, Technician, Department of Plant Pathology, North Dakota State University, Fargo 58105. Plant Dis. 69:720-721. Accepted for publication 11 February 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-720.

Rust nurseries were established at five North Dakota locations to evaluate resistance of wheat (Triticum aestivum and T. turgidum) cultivars to the natural Puccinia recondita f. sp. tritici population. The commercially grown hard red spring wheat cultivars Marshall, Len, Alex, Coteau, Walera, Solar, and Stoa are resistant to P. recondita and provide excellent protection against the natural population. Many spring wheat cultivars grown in North Dakota have susceptible reactions with low severities. Severities have increased on Butte, Olaf, and Waldron between 1982 and 1984. Most durum wheat cultivars have low coefficient of infection values and are probably not damaged by leaf rust. Most winter wheat cultivars grown in North Dakota are susceptible to P. recondita and can be damaged by rust. Virulence of the natural population was evaluated on near-isogenic lines. Annual shifts in the natural population were recorded. Lines with leaf rust-resistant genes Lr3ka, Lr9, Lr11, Lr16, Lr17, Lr19, Lr21, Lr24, Lr25, and Lr30 were resistant to the greatest percentage of field collections of P. recondita.