1. Plant Disease
  2. Host and Disease Descriptions

Wheat (Triticum aestivum)-Leaf Rust (Brown Rust)

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Latest revision: 
March 2024
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Fungicide Effectiveness as Seed Treatments for Cereal Diseases

Cause A fungus, Puccinia triticina (formerly P. recondita f. sp. tritici), which overwinters on volunteer wheat, barley, and certain wild grasses. The fungus overwinters in Oregon mostly in the red spore (urediniospore) stage. Early-maturing wheat varieties largely escape serious rust damage. Leaf rust is generally present and can cause serious yield losses, especially in combination with Septoria spp.

Symptoms Round to oblong, brick-red pustules (uredinia) appear on leaves, stems, and later on heads. As the crop ripens, black spores (telia) are produced.

Cultural control

  • Use early-maturing varieties.

Chemical control

Seed treatments reduce seedling infections.

  • Dividend Extreme at 4 fl oz/100 lb of winter wheat or triticale seed. Do not graze green forage for 55 days after planting. See label for reentry restrictions.
  • Dividend XL RTA at 10 fl oz/100 lb of winter wheat seed. Do not graze green forage until 55 days after planting. See label for reentry restrictions.
  • Raxil MD at 5 to 6.5 fl oz/100 lb seed plus a dye. See label for reentry restrictions.

Foliar applications can be made when the disease is severe.

  • Demethylation-inhibiting (DMI) fungicides (Group 3) are labeled for use.
    • Alto 100SL at 3.0 to 5.5 fl oz/A applied between Feekes Stage 8 and 10.5.1 Preharvest interval is 21 days for forage and hay, 30 days for grain and straw. 12-hr reentry.
    • Bumper 41.8 EC at 4 fl oz/A. May be applied until Feekes growth stage 10.5. Do not treat within 30 days of harvest for forage or hay. 12-hr reentry.
    • Miravis Ace B at 4 fl oz/A at flag-leaf emergence (Feekes stage 8) but not after Feekes 10.5.4. Do not apply within 7 days of harvest for forage or hay. 12-hr reentry.
    • Proline 480 SC at 4.3 to 5.0 fl oz/A on 14-day intervals. Preharvest interval is 30 days. 12-hr reentry.
    • PropiMax EC at 4 fl oz/A as a single application per season, no later than the end of flowering (Feekes 10.5). Do not graze or feed treated forage to livestock or harvest treated crop for hay or silage. After harvest, straw may be used for bedding. Do not apply within 40 days of harvest. 12-hr reentry.
    • Tebuzol 3.6F at 4 fl oz/A at flag-leaf emergence up to the end of flowering. Do not apply within 30 days of harvest. 12-hr reentry.
    • Tilt at 4 oz/A at flag-leaf emergence (Feekes stage 8) but no later than Feekes 10.5. Do not apply within 7 days of harvest for forage or hay. 12-hr reentry.
    • Topguard at 10 to 14 fl oz/A on 7-day intervals. Preharvest interval is 0 days for forage, 15 days for hay, and 30 days for grain. 12-hr reentry.
  • Dithane F-45 Rainshield at 1.6 quarts/A on 7- to 10-day intervals. Apply at the onset of disease or when plants are in the tillering to jointing stage up to the end of flowering (Feekes 10.5). 24-hr reentry.
  • JMS Stylet-Oil at 1 to 2 pints/A is labeled for use in Oregon (SLN OR-120011, SLN OR-120012). Up to three (3) applications can be made starting when the first node of the stem is visible (Feekes 6) through the end of flowering (Feekes 10.5). Do not spray if foliage is wet or if the temperature is below 32°F, above 90°F or when plants are under heat or moisture stress. 4-hr reentry. O
  • Strobilurin fungicides (Group 11) are labeled for use. Do not make more than one (1) application of a Group 11 fungicide before alternating to a labeled fungicide with a different mode of action.
    • Aftershock at 2 to 4 fl oz/A on 14- to 21- day intervals up to late head emergence (Feekes 10.5). Make no more than one (1) application prior to harvest of wheat forage. Do not apply within 7 days of harvest for forage and hay; 40 days of harvest for grain and straw. 12-hr reentry.
    • Headline at 6 to 9 fl oz/A. Apply no later than the end of flowering (Feekes 10.5). Preharvest interval is 14 days for hay and forage. 12-hr reentry.
    • Quadris Flowable at 4 to 12 fl oz/A up to late head emergence (Feekes 10.5). Do not apply within 7 days of harvest for forage and hay and 14 days of grazing. 4-hr reentry.
  • Succinate dehydrogenase inhibitors (SDHI) fungicides (Group 7) are labeled for use and include the following fungicide as well as other formulations. SDHI fungicides should always be mixed with a DMI fungicide to avoid selection for fungicide resistance.
    • Vertisan (Group 7) at 10 to 24 fl oz/A on 7- to 14-day intervals through flowering (Feekes 10.5.1). Do not make more than two (2) sequential applications before alternating to a labeled fungicide with a different mode of action (non-Group 7). Preharvest interval is 0 days for forage and hay. 12-hr reentry.
  • Premixed fungicides are available for use. Do not make more than one (1) application of any Group 11 fungicide before alternating to a labeled fungicide with a different mode of action.
    • Dexter Max (Group M3 + 11) at 2.1 lb/A on 7- to 10-day intervals. Applications may be applied up to Feekes growth stage 10.5. Preharvest interval for hay is Feekes growth stage 10.5, but no less than 26 days; grain and straw is 45 days. 24-hr reentry.
    • Dexter Xcel (Group M3 + 11 +3) at 48 fl oz/A. The single application may be applied up to Feekes growth stage 10.54. Preharvest interval is 30 days. 24-hr reentry.
    • Miravis Ace (Group 3 + 7) at 13.7 fl oz/A. For use in Oregon and Washington only. Apply between Feekes 10.3 and 10.5.4 for the control of late season rusts. Harvest interval is 7 days for forage and hay. 12-hr reentry.
    • Priaxor (Group 7 + 11) at 4 to 8 oz/A immediately after flag leaf emergence but no later than the beginning of flowering (Feekes 10.5). Preharvest interval is 14 days for forage and chopped feed. 12-hr reentry.
    • Quilt or Quilt Xcel (Group 3 + 11) at 10.5 to 14 fl oz/A when the flag leaf is 50% to fully emerged. Applications may be made no closer than a 14-day interval and may be applied up to Feekes growth stage 10.5. Do not make more than two (2) applications per season. Preharvest interval is 7 days for forage and hay. 12-hr reentry.
    • Stratego (Group 3 + 11) at 10 fl oz/A. Do not apply after flag-leaf emergence (Feekes stage 8). Do not make more than two (2) applications per season. Do not apply within 35 days of harvest. See label for grazing, forage, and hay restrictions. 12-hr reentry.
    • Trivapro (Group 3 + 7 + 11) at 9.4 to 13.7 fl oz/A beginning when the flag leaf is 50% to fully emerged, up through full head emergence. Do not make more than two (2) sequential applications of Trivapro or other Group 7 or Group 11 fungicides. Preharvest interval is 7 days for forage and hay, 14 days for grain. 12-hr reentry.