Cause Colletotrichum coccodes (formerly C. atramentarium), a fungus that is saprophytic part of its life cycle and may survive from year to year in the soil and infected crop residues. Solanaceous crops and weeds are all hosts. Seed may also be infected. Free moisture and mild temperatures are conducive for disease with 68°F to 76°F being optimum for infection. Wounding of the plant by mechanical injury or other pathogens facilitates infection by C. coccodes.
Symptoms Round, sunken spots appear on green and ripe fruit, especially where fruit are in contact with the soil. Numerous black microsclerotia form in concentric rings within spots. Spores develop around the center of fruit spots when under humid conditions, the area darkens and later contains pinkish gelatinous spore masses. Infections of green fruit may remain latent until after harvest. Seedlings often have the disease, which later moves into developing foliage but the small leaf spots are typically overlooked. Such infections are often unnoticed until fruit starts to grow, at which time the fruit-rot phase may become serious.
Cultural control
- Use pathogen-free seed.
- Practice a three-year rotation between plantings of crops in the solanaceous family.
- Control night shades and other solanaceous weeds throughout the crop rotation period.
- Use drip rather than overhead irrigation.
- Destroy all plant debris by incorporating into the soil.
Chemical control
- Aprovia Top (Group 7 + 3) at 10.5 to 13.5 fl oz/A on 7- to 10-day intervals. Do not make more than two (2) sequential applications before alternating to a labeled fungicide with a different mode of action. Preharvest interval is 0 days. 12-hr reentry.
- Bravo WeatherStik (Group M5) at 1.5 pints/A or Bravo Ultrex at 1.4 lb/A on 7- to 10-day intervals. Preharvest interval is 3 days. 12-hr reentry.
- Copper products (Group M1) are not recommended as stand-alone materials.
- Badge SC at 0.75 to 1.5 pints/A and 1.5 Tbsp/1,000 sq ft in greenhouses on 7- to 10-day intervals. Preharvest interval is 0 days. 24-hr reentry for greenhouse use; 48-hr reentry for all other applications.
- Champ Formula 2 at 1.33 pints/A. 48-hr reentry.
- Cueva at 0.5 to 2 gal/100 gal water on 7- to 10-day intervals. May be applied on the day of harvest. 4-hr reentry. O
- Cuprofix Ultra 40 Disperss at 1.25 lb/A on 7- to 10-day intervals. 48-hr reentry.
- Kocide 2000 at 1.5 lb/A or Kocide 3000 at 0.75 to 1.5 lb/A on 7- to 10-day intervals. 48-hr reentry. O
- Liqui-Cop at 2 teaspoons/gal water. H
- Nu-Cop 50 DF at 1.5 lb/A on 7- to 10-day intervals. 48-hr reentry. O
- Echo 720 (Group M5) at 1.5 pints/A on 7- to 10-day intervals. Preharvest interval is 3 days. 12-hr reentry.
- Inspire Super (Group 3 + 9) at 16 to 20 fl oz/A on 7- to 10-day intervals with no more than two (2) sequential applications. Preharvest interval is 0 days. 12-hr reentry.
- Mettle 125 ME (Group 3) at 6 to 8 fl oz/A on 7- to 14-day intervals. Application can be made the day of harvest. 12-hr reentry.
- Orondis Opti (Group M5 + 49) at 1.75 to 2.5 pints/A on 7- to 10-day intervals. Do not apply more than two (2) sequential applications. Preharvest interval is 3 days. 12-hr reentry.
- OSO 5% SC (Group 19) at 3.75 to 13 fl oz/A on 7- to 14-day intervals. Can be applied the day of harvest. 4-hr reentry. O
- Quadris Top (Group 3+11) at 8 to 14 fl oz/A on 7- to 10-day intervals. Preharvest interval is 0 days. 12-hr reentry.
- Regalia at 1 to 4 quarts/A plus another fungicide on 7- to 10-day intervals. Does not benefit from the addition of an adjuvant. Preharvest interval is 0 days. 4-hr reentry. O
- Rhyme (Group 3) at 7 fl oz/A. Alternate or tank-mix with a non-Group 3 fungicide for resistance management. Preharvest interval is 0 days. 12-hr reentry.
- Strobilurin fungicides (Group 11) are labeled for use. Do not make more than one (1) application of a Group 11 fungicide before alternating to a labeled fungicide with a different mode of action.
- Quadris Flowable at 6 to 15.5 fl oz/A or Quadris Top at 12 to 14 fl oz/A on 7- to 14-day intervals. Preharvest interval is 0 days. 4-hr reentry for Quadris Flowable, 12-hr reentry for Quadris Top.
- Trilogy at 0.5% to 1%. Not labeled for use in Oregon. Do not use above 90°F or when plants are under heat or moisture stress. Do not use when foliage is wet as good coverage is essential. Poor control as a stand-alone product. 4-hr reentry. O
- Premixes of Group 7 + 11 fungicides are available for use.
- Priaxor Xemium Brand at 4 to 8 fl oz/A on 7- to 14-day intervals. Preharvest interval is 0 day. 12-hr reentry.
Biological control Efficacy in the Pacific Northwest is unknown.
- Actinovate AG at 3 to 12 oz/A as a foliar spray on 7- to 14-day intervals. 4-hr reentry. O
- Actinovate Lawn & Garden at 1/2 to 1 teaspoon/gal water. H O