Determining the pathogenicity of Elsinoe australis on different citrus cultivars and efficacy of organic packinghouse treatments on the viability of Elsinoe australis.

摘要

Sweet orange scab (SOS) is still an exotic fungal disease of citrus in the United States caused by Elsinoe australis. SOS can cause significant damage to the fruit of sweet orange, limes, lemons, mandarins, satsuma, and grapefruit. SOS causes scab pustules that can considerably affect the aesthetic value of fruit, thereby reducing the marketability and fresh fruit value of the fruit. Recently, sweet orange scab has been found to be present, in some cases widespread throughout the citrus producing regions of Texas, Florida, Louisiana, Arizona and Mississippi. To study the pathogenicity of E. australis, pathogenicity tests by artificial inoculation were conducted on the detached leaves and fruit of organic Satsuma, lemon, and grapefruit. Also, the viability of E. australis under simulated laboratory and real-time packinghouse treatments was studied. Moreover, the efficacy of treatments on the viability of the E. australis on organic fruit was also investigated. Pathogenicity studies of fourteen different isolates of E. australis indicated susceptibility of detached leaves of satsuma, grapefruit and lemon under the required optimal environmental conditions. Detached fruit studies showed the pathogenicity of only seven isolates of E. australis. Simulated and real-time packinghouse studies of organic citrus fruit showed that packinghouse treatments significantly decreased the viability of E. australis after exposure to peroxyacetic acid solution, temperature and wax treatments.;Key words: Elsinoe australis, organic citrus, pathogenicity, packinghouse, sweet orange scab.