Prepared by Rob Last.
Cucurbit downy mildew has been identified in South Carolina this morning (5/25/22). The identification came from a field of cucumbers in Bamberg County.
Please remember to make fungicide applications seven days apart, a stretch longer than this is likely to increase the potential for disease spread.
For cucumbers, some suggested products to use in rotation are:
- Omega ( Fluazinam 7 day PHI in Cucumbers)
- Bravo (clorothalonil)
- Ranman (Cyazofamid)
- Presidio (fluopicolide)
- Orondis Opti (Oxathiapiprolin and clorothalonil never use Orondis ultra in cucumbers)
- Elumen (Ethaboxam)
- Gavel (Zoxamide and Mancozeb)
For cantaloupes:
- Ranman (Cyazofamid)
- Presidio (fluopicolide)
- Orondis Opti (Oxathiapiprolin and clorothalonil never use Orondis ultra in cantaloupes)
- Elumen (Ethaboxam)
- Gavel (Zoxamide and Mancozeb)
- Manzate (Mancozeb)
For squash and watermelons (At this point, squash and watermelon probably are not at risk of downy mildew, since the squash strain hasn’t yet moved out of South Florida.):
- Ranman (Cyazofamid)
- Orondis Opti (Oxathiapiprolin and clorothalonil)
- Orondis Ultra (Oxathiapiprolin and mandipropamid)
- Gavel (Zoxamide and Mancozeb)
- Manzate (Mancozeb)
Remember to limit the number of Orondis applications to 1/3 of the spray program. So if making 1 to 5 applications, just one should be Orondis. If making 6 to 8 applications, then two may be Orondis. For cucumbers, we suggest just one application of Orondis per crop.
The South Carolina Grower 