Epidemiological Characteristics of Scab of Japanese Apricot in Korea

Abstract

Scabs caused by Venturia carpophila greatly reduce the quality of the fruits of the Japanese apricot (Prunus mume) when the disease is not properly managed. The disease produces a superficial blemish that is unlikely to affect the overall yield of processed fruit, but reduce the value of fruit intended for the fresh market. Incidence rates of scab at sprayed and unsprayed orchards range from 0% to 21.5% and from 30.2% to 100%, respectively, in the major cultivation regions of Jeonnam Province during the growing season of 2009. The trends in disease progress were quite similar, regardless of regions, and cultivar Namgo was relatively less damaged by scab compared to cultivar Cheonmae among the tested Japanese apricot cultivars. The fruits on branches 1.5 m above the infected Japanese apricot trees and the stem-end parts of the infected fruits were more severely damaged by scabs, possibly because of rain and run-off facilitate dissemination of conidia of V. carpophila and subsequent infection of the fruits or branches. The conidia of V. carpophila were dispersed from March 24 to April 26 in 2010, and more conidia were dispersed from 2-year-old branches than 1-year-old branches. Since the control efficacies were higher than 90% after more than two applications of Trifloxystrobin WG at 10-day-intervals from mid April, it is that effective fungicides be applied at least two times at 10-day-intervals from the middle of April to manage scabs of Japanese apricot in orchards.

Global distribution and management of peach diseases

“…The pathogen overwinters as mycelia in twig lesions or as chlamydospores on vegetative tissue or in the bark of 1-year-old shoots. Besides peach, it also affects black plum, apricot, and almond (Fisher 1961;Kim et al 2017;González-Domínguez et al 2017;Dar et al 2019;Zhou et al 2021c). V. carpophila can cause severe damage to peach production in Asia, North America and Europe (EPPO 2021).…”

Genetic diversity of Venturia carpophila populations from different hosts and geographic regions in China

“…Scab is one of the most serious diseases on peach in China, which can cause defoliation and tree weakening, and more susceptible to chilling and freezing injuries (Zhou et al, 2021a). Typical symptoms on fruits are black freckles, spots, and/ or scabs of variable sizes, distribution and density, irregularly circular to oval lesions, developing a slightly raised dark-brown purple border and be slightly raised and corky in appearance (Scherm et al, 2008;Chen et al, 2017;Kim et al, 2017; Figure 1). Multiple spots on fruits often merge, leading to cracking of the skin (Figures 1A,B,E).…”