Genetic analyses by the Quesada laboratory at NC State found that different clades of P. cubensis vary for the predominant mutations conferring resistance. These findings of clade-specific resistances can facilitate the design of more effective fungicide programs tailored to crop and region.
Pseudoperonospora cubensis
CucCAP scientist examines economic impacts of reduced fungicide efficacy against downy mildew
Resistance to fungicides is a concern with cucumber downy mildew, Pseudoperonospora cubensis clade 2. 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.
CucCAP researchers develop new methods for detection and analysis of downy mildew pathogen on cucumber
Researchers in Dr. Mary Hausbeck’s group at MSU have developed a highly sensitive DNA-based protocol to genetically distinguish between spores of cucumber downy mildew and hop downy mildew from spore trap samples. The enhanced sensitivity enables detection 5-10 days before symptoms appear in cucumber fields, providing a broader window for initiation of chemical control.
CucCAP scientists translate genomic studies into novel detection method for precision management of downy mildew outbreaks
Downy mildew caused by Pseudoperonospora cubensis is the most destructive foliar disease affecting cucurbit crops. Genomic studies by Dr. Lina Quesada-Ocampo and colleagues at North Carolina State University showed that different isolates preferentially infect different cucurbit crops. From this information, a multiplex PCR-based assay was combined with spore trapping to identify which crops are most at risk. These results can facilitate timely and crop-specific fungicide application prior to appearance of symptoms in sentinel plots.
Ontario CDM Spore Trap Network August update
University of Geluph researchers monitor Cucurbit downy mildew in Kent and Norfolk counties using spore traps.
Ontario CDM Spore Trap Network July update
Spore traps installed on June 7th in Ontario Canada detected no Cucurbit downy mildew until July 29, 2021.
