Pacific Northwest Plant Disease Management Handbook

Swiss Chard (Beta vulgaris subsp. cicla)-Damping-off

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Cause Pythium spp. and Rhizoctonia solani are soil-infesting microbes that can build up rapidly and attack young germinating seedlings when soil is moist.

Symptoms Stems are attacked as young plants emerge. Plants wilt, fall over, and die. Germinating seed also can be attacked, rotting plants before they reach the soil surface.

Cultural control

  • Manage the crop to promote rapid and vigorous seedling growth.
  • Do not overwater as wet soils promote Pythium disease.

Chemical control

  • Use seed treatments.
    • Allegiance-FL at 0.1 to 0.75 fl oz/100 lb seed plus a dye. Controls Pythium spp. only. See label for reentry restrictions.
    • Captan 4F at 12 fl oz/100 lb seed plus a dye.
    • Dynasty at 0.1 to 0.38 fl oz/100 lb seed plus a dye. 4-hr reentry.
    • Maxim 4FS at 0.08 to 0.16 fl oz/100 lb seed plus a dye. Controls Fusarium and Rhizoctonia spp. See label for reentry restrictions.
    • MetaStar 2E AG at 4 to 8 pints/A as a preplant or at planting treatment. Controls Pythium spp. 48-hr reentry.
    • 42-S Thiram at 8 fl oz/100 lb seed plus a dye. See label for reentry restrictions.
  • Quadris at 0.4 to 0.8 fl oz/1000 row feet applied in a 7-inches or less band either in-furrow at planting or as a directed spray at cultivation for Rhizoctonia. 4-hr reentry.
  • Ridomil Gold SL at 1 to 2 pints/A as a soil spray (broadcast or banded) if Pythium spp. are a problem. Incorporate 2-inches deep when used. 48-hr reentry.

Biological control

  • Actinovate AG at 3 to 12 oz/A as a soil drench at planting. 1-hr reentry. O
  • Actinovate Lawn & Garden at 0.5 to 1 teaspoon/gal water. H O
  • Double Nickel LC at 0.5 to 4.5 pints/A as a soil drench at planting. 4-hr reentry. O
  • Rootshield Home and Garden at 1 to 3 Tbsp/gal water as a soil drench at planting. H O
  • Rootshield WP at 3 to 5 oz/100 gal water for greenhouse soil drench and field chemigation or at 16 to 32 oz/A as an in-furrow spray. 0-hr reentry. O
  • SoilGard 12G at 0.5 to 10 lb/A at 4-week intervals will suppress Pythium and Rhizoctonia. See label for specific application types and timings. Can be applied on the day of harvest. O

Pscheidt, J.W., and Ocamb, C.M. (Senior Eds.). 2023 Pacific Northwest Plant Disease Management Handbook.
© Oregon State University.

Use pesticides safely!

  • Wear protective clothing and safety devices as recommended on the label. Bathe or shower after each use.
  • Read the pesticide label—even if you’ve used the pesticide before. Follow closely the instructions on the label (and any other directions you have).
  • Be cautious when you apply pesticides. Know your legal responsibility as a pesticide applicator. You may be liable for injury or damage resulting from pesticide use.

Trade-name products and services are mentioned as illustrations only. This does not mean that the participating Extension Services endorse these products and services or that they intend to discriminate against products and services not mentioned.

H - Home garden packaging commonly available.     O - Acceptable in organic production.