Determination of Alternaria Brown Spot (Alternaria alternata f.sp. citri) Disease on Minneola Tangelo in ?ukurova Region

摘要

In this study, the incidence and severity of Alternaria brown spot disease (Alternaria alternata f.sp. citri) in the ?ukurova region were determined. Thirty-five Minneola tangelo orchards, with a total area of 2497 da, in 24 different locations were surveyed for this purpose. Leaf infections in all orchards were observed in the spring flushing period. Disease severity was found to be 0-10 % in 10 orchards, 11-20 % in 10 orchards, 21-30 % in 7 orchards, 31-40 % in 5 orchards, 42.5 % in 1 orchard and 62.3 % in 1 orchard. However, infections on the summer flushes were higher than 10 % in only 9 orchards. Fruit infections were generally correlated with spring flush infections. The ratio of infected fruits was higher than 10% in 16 orchards, and the highest ratio of infected fruits was observed to be 72%. The results sowed that thee is a positive corelation between disease severity and relative humidity in orchards and also hyperflushing of twigs.