Potential Distribution of Invasive Boxwood Blight Pathogen (Calonectriapseudonaviculata) as Predicted by Process-Based and Correlative Models

Abstract

Boxwood blight caused by Cps is an emerging disease that has had devastating impacts on Buxus spp. in the horticultural sector, landscapes, and native ecosystems. In this study, we produced a process-based climatic suitability model in the CLIMEX program and combined outputs of four different correlative modeling algorithms to generate an ensemble correlative model. All models were fit and validated using a presence record dataset comprised of Cps detections across its entire known invaded range. Evaluations of model performance provided validation of good model fit for all models. A consensus map of CLIMEX and ensemble correlative model predictions indicated that not-yet-invaded areas in eastern and southern Europe and in the southeastern, midwestern, and Pacific coast regions of North America are climatically suitable for Cps establishment. Most regions of the world where Buxus and its congeners are native are also at risk of establishment. These findings provide the first insights into Cps global invasion threat, suggesting that this invasive pathogen has the potential to significantly expand its range.

Epidemiology of boxwood blight in hotspots of western North Carolina and Virginia and validation of the boxwood blight infection risk model

“…Boxwood blight was rst discovered in the United Kingdom 4 and New Zealand in the mid-1990s 5 , and has now spread widely across Europe, Asia and North America. In the United States, boxwood blight was initially identi ed in North Carolina and Connecticut in 2011 6 , and has now spread to 30 states 7 , risking more than 90% of boxwood production in the United States 8, 9 . Total losses from boxwood blight have been signi cant, with Connecticut state alone incurring losses exceeding $3 million within the rst year of detection 10 .…”

“…Knowledge of the weather conditions that favour disease development is also useful in developing strategies for limiting fungicide applications as fungicides are applied according to the risk of infection 24 . Additionally, this knowledge can be used to identify areas at risk where the pathogen is either present or has not (yet) been introduced 9,25 .…”

Evaluation of fungicides for management of boxwood blight caused by Calonectria spp. under field conditions in Northern Germany

“…In the USA alone, this disease has spread to over 30 states, putting at risk more than 90% of the nation's boxwood production (Hall et al 2021). This pathogen threatens boxwood crops, plantings and forests globally (Barker et al 2022).…”