Cause Pythium spp., Rhizoctonia solani, and Fusarium spp. Pythium and Rhizoctonia solani have been detected on diseased cilantro in Oregon; Fusarium has been implicated in diseased cilantro growing in Canada, Puerto Rico, and other regions overseas. Pythium is favored by cool, overly wet soil conditions, Rhizoctonia by warm soil temperatures, and Fusarium can cause seedling disease over a wide range of temperatures.
Symptoms Seeds either fail to emerge from soil or collapse soon after emergence, after a girdling canker develops at the soil line.
Cultural control
- Plant seed under optimal conditions for quick emergence and vigorous growth.
- Use sterile soil or potting mix to start seeds. Also disinfect any tools and equipment that might be used and contaminate the media.
- Avoid reusing pots or trays from a previous crop for propagation. If pots must be reused then wash off all debris and soak in a sanitizing solution or treat with aerated steam for 30 min.
Chemical control
- Allegiance-FL at 0.75 fl oz/100 lb seed plus a dye. To control Pythium spp. only. See label for reentry restrictions.
- 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. To control Fusarium, Rhizoctonia, and other fungal spp. 12-hr reentry.
- Thiram 42-S at 2.5 to 5.0 fl oz/100 lb plus a dye. For use in OR (SLN OR-100002) and WA (SLN WA-060022, WA-060023) only. For export only in WA but can be used in OR for seed crops.
Biological control
- Actinovate AG at 3 to 12 oz/A as a soil drench at planting. 4-hr reentry. O
- Actinovate Lawn & Garden at 0.5 to 1 teaspoon/gal water. H O
- Bexfond at 7 to 14 fl oz/A. O
- Double Nickel LC at 0.5 to 4.5 pints/A as a soil drench at planting. 4-hr reentry. O
- Mycostop at 0.07 oz/half lb seed or Mycostop Mix at 0.05 to 0.08 oz/lb seed. 4-hr reentry.
- Prestop WG. 4-hr reentry. 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. 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
- Stargus at 3 to 4 quarts/A as a soil drench on 10- to 21-day intervals. Preharvest interval is 0 days. 4-hr reentry. O
Reference Hershman, D.E., Varney, E.H., and Johnson, S.A. 1986. Etiology of parsley damping-off and influence of temperature on disease development. Plant Disease 70:927-930.