Control of Stripe Rust and Leaf Rust of Wheat with Seed Treatments and Effects of Treatments on the Host. R. Rakotondradona, Research Assistant, Department of Plant Pathology, Washington State University. R. F. Line, Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, Pullman, WA 99164. Plant Dis. 68:112-117. Accepted for publication 8 August 1983. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1984. DOI: 10.1094/PD-68-112.

In greenhouse and field studies at Mount Vernon, Paterson, Pullman, and Walla Walla, WA, triadimefon applied as a slurry to wheat (Triticum aestivum L.) seed at 0.5 g a.i./kg (0.6 oz a.i./bu) or higher controlled both stripe rust (Puccinia striiformis West.) and leaf rust (Puccinia recondita Rob. ex. Desm.) from seedling emergence through the boot stage of plant growth. For winter wheat, control was effective from October to May. Triadimefon at 0.25 g a.i./kg (0.3 oz a.i./bu) controlled the rusts through the tillering stage of plant growth. Fenarimol controlled both rusts at 2 g a.i./kg (2.4 oz a.i./bu) but was phytotoxic and did not control rust at lower rates. Butrizol was effective against leaf rust but not stripe rust. Benomyl at 0.5–2 g a.i./kg (0.6–2.4 oz a.i./bu) and oxycarboxin at 0.5–3.0 g a.i./kg (0.6–3.6 oz a.i./bu) provided only slight control. CGA-64251 reduced the rust but was phytotoxic at 0.12–1 g/kg (0.15–1.2 oz/bu).

Keyword(s): chemical control, chemotherapy, fungicides.