Biology of Gymnosporangium asiaticum
Studies on biological factors in regard to infection of pears and junipers by Gymnosporangium asiaticum (EPPO A1 pest) were carried out in the Republic of Korea. Teliospore germination and sporidial formation were highest at temperatures of 15-20ø C at a high relative humidity. Sporidia had a very low drought resistance and their germability was lost after one hour under room conditions. A minimum of 8 h leaf wetness was required for sporidia to infect pear leaves. Sporidia developed more pycnidial lesions on young leaves; older leaves were not as highly susceptible.
Sources
Lee, D.H. (1990) Studies on the several factors in relation to pear rust infection caused by Gymnosporangium asiaticum Miyabe et Yamada.
Korean Journal of Plant Pathology 6, 65-72.