Carrot (Daucus carota)-Damping-off

Cause Mainly Pythium spp. but also Rhizoctonia sp. and Fusarium spp. These soil-infesting fungi or fungus-like microorganisms are widespread and attack young and germinating seedlings of many plants.

Symptoms Seedlings attacked at ground level develop a water-soaked, discolored stem and topple over. Infected plants seldom recover.

Cultural control

  • Earliest seedings should go on raised beds in well-drained fields.
  • Use a precision seeder so seedlings are evenly spaced and not touching one another.

Chemical control

  • Treat seed with fungicide.
  • Acquire at 0.7 fl oz/100 lb seed plus a dye. For control of Pythium only. See label for reentry restrictions.
  • Apron XL LS at 0.32 to 0.64 fl oz/100 lb seed plus a dye. For control of Pythium spp. See label for reentry restrictions.
  • Dynasty at 0.1 to 0.38 fl oz/100 lb seed plus a dye. 4-hr reentry.
  • Maxim XL at 0.167 to 0.334 fl oz/100 lb seed plus a dye. For control of pathogenic Fusarium and Rhizoctonia spp. Additional Apron XL LS is required and rate depends on disease pressure, see label. See label for reentry restrictions.
  • Thiram 50 WP dyed at 8 oz/100 lb seed (not labeled for Oregon) or 42-S Thiram at 8 fl oz/100 lb seed plus a dye. See label for reentry restrictions.
  • Soil applied fungicide.
  • Quadris Flowable at 0.4 to 0.8 fl oz/1000 row feet applied in a 7-inch or less band either in-furrow at planting or as a directed spray at cultivation. 4-hr reentry.
  • Ridomil Gold SL at 0.51 to 1.3 pints/A may be applied preplant incorporated or as a band after planting where Pythium are a problem. 48-hr reentry.

Biological control

  • Double Nickel LC at 0.5 to 4.5 pints/A for soil application on 14- to 28-day intervals. Can be applied the day of harvest. 4-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
  • T-22 HC at 0.088 to 3.52 lb/100 lb seed (commercial seed treatment) or 4 to 8 oz/A (planter box) will suppress certain fungal path-ogens including Fusarium, Rhizoctonia, and Pythium spp. Do not use in alkaline soils or if soil is below 50°F. 4-hr reentry.