Improved potato quality by reduced skin blemish diseases (scab and scurf) in Norwegian potato production

Bakgrunn

Potato has approx annually a wholesale value of NOK 500,000,000. Skin blemish diseases (scurf and scab) have become an increasing problem in Norway, mainly for the fresh marked potato. The quality problem is caused by several pathogens including Streptomyces spp, (common scab), Spongospora subterranea (powdery scab), Helminthosporium solani (silver scurf), Rhizoctonia solani (black scurf), Polyscytalum pustulans (skinspot), Colletotrichum coccodes (black dot) and free-living nematodes (Pratylenchus penetrans). The yearly cost of these diseases for the fresh market potato business and growers of potatoes for the potato industry is approx NOK 37,000,000. This projectaims at development and implementation of methods for reduction of skin blemish diseases in potato by 30 %. Skin blemish pathogens can be transmitted both from the seed tubers and from the soil. However, the importance of seed tubers as primary inoculum source varies among the different pathogens. There is limited knowledge of the importance of the different scab and scurf causing organisms in Norway, thus a survey will be performed. Different control methods to reduce development of skin blemish diseases will be investigated under controlled growth conditions and in the field.

Mål

The project aims to improve the control of skin blemish diseases on potato in Norway.

Fremgangsmåte

Tested methods/conditions will include irrigation, pH levels, S-fertilizer and post-harvest curing strategies. Real time PCR diagnostic methods will be explored and deployed toidentify and quantify the amount of the different pathogens in tubers and soil. Based on case studies with such methods, we will define criteria to predict the suitability of a field for potato production and to predict the need for seed treatment of a potato lot or other cultural control strategies.

Samarbeid

Improved skin blemish control methods will be implemented in the guidelines for potato production via the web-site: www.potet.no.