Cause Pythium spp., Rhizoctonia solani, and Fusarium spp. The first two are documented as pathogenic on parsley; Fusarium oxysporum has been recovered from diseased parsley in Oregon and California. Pythium is favored by cool, overly wet soil conditions, Rhizoctonia by warm soil temperatures, and Fusarium tolerates a wider host range.
Symptoms Seeds either fail to emerge from soil or collapse soon after emergence and a girdling canker develops at the soil line.
- 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.
- Allegiance-FL at 0.75 fl oz/100 lb seed plus a dye. To control Pythium spp. only. See label for reentry restrictions.
- Apron XL at 0.085 to 0.64 fl oz/100 lb seed when Pythium is a problem. 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.
- Orondis Gold (Group 49 + 4) at 13.9 to 27.8 fl oz/A as an in-furrow, transplant water or banded soil application at planting. May be applied through drip after emergence. Preharvest interval is 7 days. 48-hr reentry.
- Thiram 42-S at 2.5 to 5.0 fl oz/100 lb seed plus a dye. For use in Oregon (SLN OR-100002) and Washington (SLN WA-060022, WA-060023) only. For export only.
- 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
- Mycostop at 0.07 oz/lb seed or Mycostop Mix at 0.05 to 0.08 oz/lb seed. 4-hr reentry.
- 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
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.