Records suggest that China has cultivated pears for well over 2500 years. China ranks first in the world in pear production, growing 75% of the world’s output. Annual production has increased twenty-fold in China since the 1950s. A key to production is protecting pears from a disease known as pear scab, which is caused by a fungus that overwinters in leaves on the ground. Spores are released as a result of rain and are carried by air currents to leaves and fruit. Scab lesions form on fruit and, as they enlarge, become large black areas. Fungicides are used in China to prevent pear scab infections.
“Pear scab (Venturia nashicola) is an economically important disease in China. The pathogen is different from the European pear scab fungus (V. pirina) and causes significant annual yield loss on pears, especially on traditional Chinese varieties. … Infection by V. nashicola can occur at any time throughout the growing season from early spring until late autumn, if environmental conditions are conducive. Leaves and fruits become gradually less susceptible to infection as they age. Pear scab in China is managed by routine application of fungicides.”
Authors: Li, B.-H.¹, J.-R. Yang², B-D. Li¹ and X.-M. Xu³
Affiliation: ¹Laiyang Agricultural College, Shangdong Province, China; ² Northwest A & F University, Shaanxi, China; ³ East Malling Research, Kent, UK.
Title: Incidence-density relationship of pear scab (Venturia nashicola) on fruits and leaves.
Publication: Plant Pathology. 2007. 56:120-127.