Impact of Calonectria Diseases on Ornamental Horticulture: Diagnosis and Control Strategies

Abstract

Diseases caused by fungi in the genus Calonectria pose a significant threat to the ornamental horticulture industries in Europe and the United States. Calonectria spp. are particularly challenging pathogens to manage in ornamental production systems and the urban landscape for multiple reasons. A high level of species diversity and poorly resolved taxonomy in the genus makes proper pathogen identification and disease diagnosis a challenge, though recent molecular phylogenetic studies have made significant advances in species delimitation. From a disease management perspective, Calonectria spp. produce long-lived microsclerotia survival structures (microsclerotia) that contaminate nursery production systems , are resistant to common cultural and chemical controls, and can survive multiple years in the absence of a susceptible plant host. Latent infection of plant material is poorly understood but likely contributes to long-distance dissemination of these fungal pathogens, including the clonal Calonectria spp. responsible for the global emergence of boxwood blight. Breeding for disease resistance represents a sustainable strategy for managing Calonectria diseases, but is challenging due to the perennial nature of many ornamental plants and high levels of susceptibility in commercial cultivars. Ultimately, long-term sustainable management of Calonectria diseases will require an improved understanding of pathogen biology as well as integration of multiple disease management strategies.

Multi-Year Field Plantings Evaluating Boxwood Cultivars for Susceptibility to the Blight Pathogens (Calonectria spp.) in Northern Germany

“…The morphologically similar Calonectria henricotiae was distinguished as a separate genetic grouping in 2005 (Gehesquière et al 2014) and identified as a separate species in 2016 (Gehesquière et al 2016). It is known to occur in Germany, Belgium, the United Kingdom, Slovenia and the Netherlands (Gehesquière 2014;Gehesquière et al 2016) as well as the Czech Republic but has not been reported from North America, Asia or New Zealand to date (Hall et al 2021;Aiello et al 2022).…”

Diversity and Distribution of Calonectria Species in Soils from Eucalyptus urophylla × E. grandis, Pinus massoniana, and Cunninghamia lanceolata Plantations in Four Provinces in Southern China

“…The genus Calonectria includes a range of important plant pathogens that are widely distributed in tropical, subtropical, and temperate regions throughout the world [ 1 , 2 , 3 ]. These aggressive pathogens can infect approximately 335 plant species residing in 100 plant families, including important agricultural, horticultural, and forestry crops [ 1 , 2 , 3 , 4 ]. Leaf blight caused by Calonectria species is considered one of the most prominent diseases of Eucalyptus plantations in China, Brazil, Colombia, Vietnam, and other countries [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ].…”

Efecto de la solarización en patógenos fungosos que afectan al Eucalipto (Eucalyptus urograndis) en condiciones de vivero

“…La integración de fungicidas con la solarización del suelo mostró una menor severidad del "damping off" en el cultivo de ají (Kadam et al, 2018). El dazomet se ha usado en los viveros como alternativa química al bromuro de metilo, encontrándose una reducción significativa sobre la incidencia de enfermedades fúngicas transmitidas por patógenos habitantes del suelo, como lo son los géneros Rhizoctonia y Cylindrocladium (Aiello et al, 2018;Santori et al, 2020;Villarino et al, 2021;Aiello et al, 2022).…”