Control of oomycete pathogens during Pyropia farming and processing using calcium propionate

The oomycete pathogens Pythium porphyrae, causing red rot disease, and Olpidiopsis spp. Olpidiopsis-blight, cause serious economic losses to Pyropia sea farms in Korea. During the washing step for processing, these proliferate rapidly, significantly reducing quality of final product. To develop non-acidic treatments pathogens, various calcium salts were tested against infectivity P. porphyrae pyropiae on gametophytes, propionate was most effective. When blades immersed 10 mM 1 h after inoculation with pathogen, infection rate both day 2 lower (7.1%) than control (>95%). Brief incubation also reduced spread infection. infected area thallus 14.3% days treatment 100 30 s. In field experiments conducted actual aquaculture farms, it has been shown that a brief s wash every two weeks can effectively reduce oomycetes throughout entire culture period. above results suggest be useful means controlling not only during laver processing but aquaculture.