Cause Alternaria cucumerina has been reported in Oregon and Washington, Ulocladium consortiale only in Washington. They are similar in form and disease symptoms and are easily confused. Research in the mid- to late 1970s in Washington showed this disease did not reduce yields under Washington conditions.
Symptoms Small tan spots turn dark brown on maturing. Often, concentric rings may be in older spots, giving them a "bulls'-eye" appearance. Coalescing spots may involve large areas of the leaf. Under northwest conditions, fruit has not been attacked.
Cultural control
- Rotate to non-host crops for 2 years.
- Plow under crop debris soon after harvest.
- Use drip irrigation to reduce the time leaves are wet, or use overhead irrigation only during the day and for short periods.
Chemical control
- Carboxamide (Group 7) formulations are registered for use. Do not make more than two (2) sequential applications before alternating to a labeled fungicide with a different mode of action.
- Endura at 6.5 oz/A on 7- to 14-day intervals. Preharvest interval is 0 days. 12-hr reentry.
- Fontelis at 12 to 16 fl oz/A on 7- to 14-day intervals. Preharvest interval is 1 day. 12-hr reentry.
- Chlorothalonil (Group M5) formulations are labeled.
- Bonide Fung-onil is available for home gardens. H
- Bravo Ultrex at 1.8 to 2.7 lb/A in water to cover. May apply through sprinkler irrigation. May be applied the day of harvest. 12-hr reentry.
- Echo 720 at 2 to 3 pints/A on 7-day intervals. Preharvest interval is 0 days. 12-hr reentry.
- Copper products (Group M1) are not recommended as stand-alone materials.
- Badge SC at 0.5 to 2.5 pints/A on 5- to 7-day intervals. Preharvest interval is 0 days. 24-hr reentry for greenhouse use; 48-hr reentry for all other applications.
- Champ WG at 1.5 to 2 lb/A on 5- to 7-day intervals. 48-hr reentry. O
- 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 to 2 lb/A on 5- to 7-day intervals. 48-hr reentry.
- Liqui-Cop at 2 to 3 teaspoons/gal water. H
- Previsto at 0.75 to 2 quarts/A on 5- to 7-day intervals. 48-hr reentry. O
- JMS Stylet-Oil at 3 to 6 quarts/100 gal water. Do not spray if temperature is below 50°F, above 90°F or when plants are wet or under heat or moisture stress. 4-hr reentry. O
- Manzate 75 DF (Group M3) at 2 to 3 lb/A. Do not apply within 5 days of harvest. 24-hr reentry.
- Mettle 125 ME (Group 3) at 8 fl oz/A on 7- to 10-day intervals. Application can be made the day of harvest. 12-hr reentry.
- Omega 500F (Group 29) at 0.75 to 1.5 pints/A on a 7- to 10-day interval. Preharvest interval is 7 days. 12-hr reentry.
- OSO 5% SC (Group M19) 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
- Regalia (Group P5) 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
- 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.
- Cabrio EG at 12 to 16 oz/A. Preharvest interval is 0 days. 12-hr reentry.
- Evito 480 SC at 3.0 to 5.7 fl oz/A. Preharvest interval is 1 day. 12-hr reentry.
- Quadris Flowable at 11.0 to 15.4 fl oz/A or Quadris Opti at 3.2 pints/A. Preharvest interval is 1 day. 4-hr reentry for Quadris Flowable; 12-hr reentry for Quadris Opti and Quadris Top.
- Reason 500 SC at 5.5 fl oz/A. Do not apply within 14 days of harvest. 12-hr reentry.
- Trilogy at 0.5% to 1%. 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. 4-hr reentry. O
- Premixes of fungicides are available and offer ease for fungicide resistance management. 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; for other fungicide groups apply no more than two (2) sequential applications alternating with another fungicide with a different mode of action.
- Aprovia Top (Group 7 + 3) at 10.5 to 13.5 fl oz/A on 7 to 14-day intervals. May be applied the day of harvest. 12-hr reentry.
- Dexter Max (Group M3 + 11) at 2.1 to 3.2 lb/A on 7- to 10-day intervals. Preharvest interval is 5 days. 24-hr reentry.
- Dexter Xcel (Group M3 + 11 + 3) at 72 fl oz/A on 7- to 10-day intervals. Preharvest interval is 7 days. 24-hr reentry.
- Gavel 75 DF (Group 22 + M3) at 1.5 to 2.0 lb/A on 7- to 10-day intervals. Preharvest interval is 5 days. 48-hr reentry.
- Inspire Super (Group 3 + 9) at 16 to 20 fl oz/A on 7- to 10-day intervals. Preharvest interval is 7 days. 12-hr reentry.
- ManKocide (Group M1 + M3) at 2 to 3 lb/A on 7- to 10-day intervals. Under moderate to severe disease pressure use the higher rate on 5- to 7-day intervals. Do not apply within 5 days of harvest. 48-hr reentry.
- Merivon Xemium (Group 7 + 11) at 4 to 5.5 fl oz/A on 7- to 14-day intervals. Preharvest interval is 0 days. 12-hr reentry.
- Miravis Prime (Group 7 + 12) at 9.2 to 11.4 fl oz/A on 7- to 14-day intervals. Preharvest interval is 1 day. 12-hr reentry.
- Orondis Opti (Group M5 + 49) at 1.75 to 2.5 pints/A on 7- to 14-day intervals. May be applied the day of harvest. 12-hr reentry.
- Pristine (Group 7 + 11) at 12.5 to 18.5 oz/A. Preharvest interval is 0 days. 12-hr reentry.
- Quadris Opti (Group 11 + M5) at 3.2 pints/A or Quadris Top (Group 11 + 3) at 12 to 14 fl oz/A. Preharvest interval is 1 day. 12-hr reentry.
- Switch 62.5WG (Group 12 + 9) at 11 to 14 oz/A on 7-day intervals. Do not apply within 1 day of harvest. 12-hr reentry.