Cause Several fungi or fungus-like microorganisms including Pythium spp., Rhizoctonia solani, Thielaviopsis basicola, and Phoma medicaginis var. pinodella, all of which are soilborne. Wrinkled-seed garden peas are more prone to damping-off than smooth-seed field peas.
Symptoms Seeds rot in soil, seedlings fail to emerge, emerged seedlings rot at the soil line and fall over, or emerged seedlings are severely stunted and do not recover.
- Do not plant peas or similar hosts in the same soil more than every 3 years.
- Plant in well-drained, noncompacted soil.
- If practical, seed in spring when soil at the 2-inch depth is above 55°F.
- Plant seed with good vigor as indicated by germination, vigor, and electro-conductivity tests.
- Plant seed at the proper depth, uniformly through the field, and avoid seed injury during planting.
- Lime acid soils to get a pH of 6.5 or 7.0.
- If the stand is lost, replant ideally in dry, warm weather, which is more favorable for germination.
- Seed treatment. If using nitrogen-fixing inoculants, use after the chemical treatment and no more than 2 hours before planting. Include at least two different active ingredients in the seed-treatment mixture to protect against at least both Pythium spp. and Rhizoctonia solani. Laboratory diagnosis of pathogens involved in damping-off events can aid greatly in choosing the best seed fungicide treatment combination for the next time legumes are planted in that site.
- Allegiance-FL (Group 4) at 0.75 fl oz/100 lb seed plus a dye for Pythium control. See label for reentry restrictions.
- Apron XL (Group 4) at 0.16 to 0.64 fl oz/100 lb seed plus a dye for Pythium control. See label for reentry restrictions.
- Captan 4F (Group M4) at 2.6 fl oz/100 lb seed plus a dye. A broad-spectrum fungicide.
- Maxim 4FS (Group 12) at 0.08 to 0.16 fl oz/100 lb seed plus a dye for Rhizoctonia and Fusarium control. See label for reentry restrictions.
- Obvius (Group 4 + 7 + 11) at 4.6 fl oz/100 lb seed plus a dye. A broad-spectrum seed fungicide combination for dry pea and field pea. 24-hr reentry.
- Stamina (Group 11) at 0.4 to 1.5 fl oz/100 lb seed plus a dye.
- 42-S Thiram at 3 fl oz/100 lb seed plus a dye. A broad-spectrum fungicide. See label for reentry restrictions.
- Vibrance (Group 7) at 0.08 to 0.16 fl oz/100 lb seed plus a dye for dry peas only. See label for reentry restrictions.
- Apply at planting or during cultivation to control Rhizoctonia spp.
- Quadris Flowable at 0.4 to 0.8 fl oz/1,000 row feet applied in a 7-inches or less band either in-furrow at planting or as a directed spray at cultivation. 4-hr reentry.
Biological control Efficacy in the Pacific Northwest is unknown.
- 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
- 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
- Prestop as a soil drench or incorporation into growing medium. 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 6 to 8 fl oz per 1,000 ft row as an in-furrow treatment. Preharvest interval is 0 days. 4-hr reentry. O