Small Grains Stripe Rust Reference Page
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Stripe Rust in Small Grains Reference Page
Pest common and scientific names: Wheat
(Triticum aestivum) -- Stripe Rust (Yellow Rust)
Cause: A fungus, Puccinia striiformis, which may oversummer on volunteer or early fall-seeded wheat and certain wild grasses. It is favored by cool summers, mild winters, and long, cool, wet springs. New races of strip rust, which may be more adapted to warmer temperatures, are aggressively attacking hard red wheats in the midwestern U.S.
Symptoms: Citron-yellow uredia (spore masses) appear in long stripes on leaves and, rarely, on stems and heads. As the crop matures, black spores (telia) are produced in stripes which are covered by the leaf epidermis.
Cultivar Resistance: Most commercial winter wheat cultivars have good to excellent resistance. Current ratings are available in extension and crop improvement association variety selection linterature.
Cultural control:
- Plant resistant cultivars.
- Seed treatments reduce seedling infections.
- Baytan 30 at 1.25 fl oz/100 lb seed plus a dye. Note: This product may reduce seedling emergence, especially if used in deep furrow drills, on late-planted winter cereals, or on poor quality seed.
- Dividend at 1 fl oz/100 lb winter wheat seed (as a prepack with Apron XL LS). Do not graze green forage until 55 days after planting. Do not plant any crop other than wheat within 30 days in fields in which treated seeds were planted.
- Foliar applications if
disease is present and conditions are expected to remain favorable.
Field scouting aids in detecting stripe rust early in the epidemic,
while the disease still can be managed through fungicide applications.
Once the crop is in the grain-filling stage, fungicide benefits are
unlikely.
- Headline at 6 to 9 fl oz/A. Do not apply more than twice per season; apply no later than the end of flowering (Feekes 10.5 ). May apply at the onset of disease. Apply in order to protect the flag leaf from infection for optimum results; to maximize yields in cereals it is important to protect the flag leaf. Do not harvest wheat hay within 14 days of last application. 12-hr reentry.
- Quadris at 6.2 to 10.8 fl oz/A. May apply immediately after jointing (Feekes 6) up to late head emergence (Feekes 10.5). A crop oil concentrate adjuvant may be added at 1.0% V/V to optimize efficacy. Do not make more than two (2) foliar applications of Quadris or other Group 11 fungicides per acre per year. Do not apply within 45 days of harvest for grain and straw. 4-hr reentry.
- Quilt at 14 fl oz/A applied when the flag leaf is 50-70% emerged. Applications may be made no closer than a 14-day interval and may be applied up to Feekes growth stage 9. Do not apply more than 0.167 lb a.i. Propiconazole-containing products/A/year. Do not apply more than 0.4 lb a.i. azoxystrobin-containing products/A/year. Make no more than two (2) applications of Quilt/A/year. Do not feed treated forage or cut green crop for hay or silage. Preharvest interval is 45 days. 24-hr reentry.
- Stratego at 10 fl oz/A at 7- to 10-day intervals if favorable conditions for disease persist. Do not apply within 35 days of harvest. 24-hr reentry.
- Tilt at 4 oz/A in not less than 15 gal/A water (ground) or 5 gal/A water (air). Apply at flag-leaf emergence (Feekes stage 8) but not after this stage. Do not graze or feed treated forage to livestock or harvest treated crop for hay or silage. Straw may be used for bedding. Do not apply more than 4 fl oz/A per season. 24-hr reentry.
Content edited by: Richard Smiley and Cynthia M. Ocamb on April 15, 2005.
Source: 2005 Pacific Northwest Insect Management Handbook
4/10/06-jn