Resistance to fungicides, such as propamocarb hydrochloride (Previcur Flex) and cymoxanil (Curzate), is a concern with cucumber downy mildew, Pseudoperonospora cubensis clade 2. Nevertheless, these fungicides still suppressed downy mildew well enough that yields of marketable-sized fruit of a susceptible slicing cucumber were much better than not spraying. Although the costliest fungicide may be the most effective at managing foliar symptoms of downy mildew, it may not increase profits over spraying a less expensive fungicide.
For Further Reading:
- Economic impacts of reduced fungicide efficacy against downy mildew on slicing cucumber
by: Anthony P. Keinath and Felipe de Figueiredo Silva
Published in Crop Protection Volume 155:105934 in May 2022.