Outbreak of Fire Blight of Apple and Asian Pear in 2015–2019 in Korea

Abstract

Erwinia amylovora, a causal bacterium of fire blight disease, is registered as a prohibited quarantine pathogen in Korea. To control the disease, the government should diagnose the disease, dig and bury the host trees when fire blight occurs. Fire blight was the first reported in 43 orchards of Anseong, Cheonan, and Jecheon in 2015, and 42.9 ha of host trees were eradicated. However, the disease spread to eleven cities, so that 348 orchards and 260.4 ha of host trees were eradicated until 2019. Fire blight of Asian pear occurred mainly in the southern part of Gyeonggi, and Chungnam province, on average of 29±9.2 orchards per year. And the age of the infected trees were mostly 20-30 years old. In apple trees, the disease occurred mainly in the northern part of Gyeonggi, Gangwon, and Chungbuk province, on average of 41±57.6 orchards per year, increased highly in 2018 and 2019. The age of infected apple trees were under 20 years old. Therefore, because the disease spread rapidly in young apple trees, spraying control agents to the trees in a timely manner and removing infected trees quickly are important to prevent the spread of fire blight in the orchard of immature trees.

Isolation of Nine Bacteriophages Shown Effective against Erwinia amylovora in Korea

“…Since 2018, the occurrence of E. amylovora infections have increased rapidly in Korea. A total of 348 orchards were buried as a public control measure from 2015 to 2019 (Ham et al, 2020).…”

Phage Cocktail in Combination with Kasugamycin as a Potential Treatment for Fire Blight Caused by Erwinia amylovora

“…Fire blight was first reported in 2015, and since then there has been an increasing number of outbreaks in South Korea, especially recently [ 40 , 41 ]. Without any regulations regarding the administration order for antibiotics to control the fire blight in South Korea, secondary agents, including kasugamycin, are widely used in general.…”

Recent spread and potential pathways for fire blight in South Korea

“…Once established, the disease can be readily spread inland by natural means such as insects and wind into flowers, shoots and growing tips on adjacent trees (van der Zwet & Bonn, 1999). All infected apple trees were under 4 years old; the young trees promote the rapid growth of the pathogen if they become diseased with fire blight (Ham et al, 2020).…”

“…Recently, this disease has spread from Europe to East Asia (Park et al, 2017;CABI, 2021;EPPO, 2021). In 2015, 43 orchards in South Korea were first confirmed to be infected by this pathogen and 17 orchards were identified in 2016, 33 orchards in 2017, 67 orchards in 2018 and 188 orchards in 2019 (Park et al, 2016(Park et al, , 2017Ham et al, 2020;Park, 2020). In 2020, this disease underwent a very strong increase, being found in 744 orchards.…”