Adapting quantitative detection methods for determining silver scurf injury thresholds both in the soil and on seed potatoes to model potential economic losses

Description

The fungal pathogen Helminthosporium solani causes silver scurf, a disease that is hard to detect, both in the soil and on harvested potatoes. The disease reduces yields and affects the appearance of the tubers, especially after storage. Fresh potato marketing strategies are based on plastic packaging and the appearance of the potatoes plays an important role. Sensitive, accurate, and affordable silver scurf detection tests are needed to reduce losses. Quantitative PCR (qPCR) tests on soil samples or potato tubers can be used to determine infection thresholds above which the risk of economic loss at planting or after storage is too high. These innovative models for quantifying and estimating the economic risk of disease transmission are a key factor in maintaining and enhancing the competitiveness of Québec potato farms.

Objective(s)

• Develop qPCR tests to determine the prevalence and detection rates of silver scurf (Helminthosporium solani) on potato tubers and in soil samples.
  Determine economic injury levels for silver scurf with respect to potato quality
• Develop innovative models to predict economic loss based on economic injury thresholds that can be applied to different stages of seed and fresh potato production
• Publish a guide on good practices for managing silver scurf in seed and fresh potato production and storage