Survey of Turkish Strawberry Production Areas for Soil-borne Fungal Diseases

Turkey is an important strawberry producing country with 376,070 t production on 13,423 hectares 2014.  Strawberry cultivation is increasing and is centered in the Mediterranean and Aegean Regions.  The production is conducted either in open field or under cover with an annual hill culture system.  The cultivars developed by the Universities of California and Florida dominate production.  It is not common to apply pre-planting fumigation in production areas and usually crop rotation is applied to avoid soil-borne pathogens.  However, both the incidences and the severity of soil-borne pathogens have been increasing and these diseases have become the major problem in production.  We surveyed important strawberry production areas to identify common soil-borne pathogens.  Plant samples were collected from provinces in Mediterranean and Aegean Regions representing the major areas of Turkish strawberry production both in Spring and Fall of 2014.  In both seasons, 300 symptomatic plant samples were cultured on potato dextrose agar including penicillin or oomycete selective media to detect the pathogens.  Macrophomina, Fusarium, Verticillium, Rhizoctonia, Colletotrichum, Phytophthora, Alternaria, Pestalotiopsis and Botrytis spp. were the commonly identified fungal and oomycetous organisms.  In most cases, the samples were infected by more than one pathogen.  There were some differences in the frequencies of pathogens for seasons and locations.  The results are significant for developing management practices needed to be employed against soil borne pathogens in strawberry production areas especially where soil fumigation is not performed.