Silver Scurf

Silver scurf on cultivar Cascade. Photo credit: B. Gundersen.

Causal Agent:

Helminthosporium solani

Biology:

H. solani is a fungal pathogen of potato tubers, but can likely survive in the soil as a saprophyte. Infection occurs during the growing season from either seed-based inoculum, or from soil inoculum. Damage by silver scurf worsens during storage by spreading on and between tubers.

Dispersal:

Silver scurf is distributed mostly on seed tubers, and is in fact commonly found on them. It is suspected to also move via contaminated soil.

Further Reading:

Potato disease specialists in the Northwest recently published a bulletin on silver scurf that we highly recommend.  It can be found in the research library section of this website and searching for “Silver Scurf Management in Potatoes.”