Updated: 7/27/2005
Downy mildew is a very destructive disease and progresses rapidly under favorable conditions. Fungicides are much more effective when applied well before symptoms are visible. Initiating a downy mildew control program after symptoms have been detected is much more likely to fail.
Results from the 2004 fungicide performance trial are available by clicking on “2004 Fungicide Trial Report” below. The most effective spray programs in this trial included the fungicides Tanos, Previcur Flex, and Gavel, tank mixed or alternated with Curzate, Manzate and/or Bravo.
In designing a fungicide program growers should also observe pre-harvest intervals and practice resistance management by alternating products belonging to different fungicide groups.
| Product & Formulation | Pre-harvest Interval (days) | Fungicide Group |
| Tanos 50WG | 3 | 11+27 |
| Previcur Flex 6F | 2 | 28 |
| Gavel 75DF | 5 | 22+M |
| Curzate 60DF | 3 | 27 |
| Manzate 75WG | 5 | M |
| Bravo 6SC | 0 | M |
For a more complete list of fungicides, click on “2005 Relative Efficacy Table” below.
The following is a sample fungicide program for cucumber downy mildew that incorporates field-tested efficacy, observes pre-harvest intervals and practices sound resistance management:
Tanos 50WG, 8 oz + Manzate Pro-Stick* 75DG, 2 lb alternated every 5 to 7 days with Previcur Flex 6F, 1.2 pt + Bravo Weather Stik* 6SC, 2 pt.
*Other labeled formulations of mancozeb include Penncozeb and Dithane; other labeled formulations of chlorothalonil include Echo and Equus.
Beginning near harvest and based on the frequency of harvest, use a product(s) with the appropriate pre-harvest interval.