Factors affecting the distribution of pine pitch canker in Northern Spain

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Fusarium circinatum is the causal agent of pine pitch canker disease (PPC), affecting Pinus species and other conifers (i.e., Pseudotsuga menziesii (Mirb.) Franco.), forming resinous cankers on the main stem and branches and causing dieback in the terminal guide. This pathogen is spreading worldwide, causing economic losses by converting plantations into standing timber without any potential for future production. The disease was recently detected in Northern Spain in plantations of Pinus radiata and forest nurseries. The aim of the work reported here was to study the role of climatic and topographic variables, soil properties, and stand characteristics on PPC. For this purpose, we surveyed 50 pine stands in Cantabria and quantified the percentage of trees showing three symptoms in each stand: canker, defoliation, and dieback. We investigated the predictive power of 30 variables using generalized linear models and hierarchical partitioning. Both approaches yielded similar results. We found that the three symptoms correlated with different explanatory variables. In addition, more trees exhibited cankers in the proximity of the coast and the Basque Country. Additionally, our results showed that low canopy cover is related to a high level of the dieback symptom. Overall, this study highlights the important variables affecting the distribution of PPC in Cantabria.

This study was made possible through the project, ‘Etiology, Epidemiology and Control of Fusarium circinatum’, sponsored by the Ministry of Rural, Marine, and Natural Environment, and with the support of the Government of Cantabria. This article is based upon work from COST Action FP1406 PINESTRENGTH (Pine pitch canker strategies for management of Gibberella circinata in greenhouses and forests), supported by COST (European Cooperation in Science and Technology) and project AGL2015-69370-R funded by MINECO and FEDER. We acknowledge the European COST Action FP1406 PINESTRENGTH that covers the costs to publish in open access. Thanks are due for the financial support to CESAM (UID/AMB/50017/2019), to FCT/MEC through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020. This research was supported by the FCT project URGENTpine (PTDC/AGRFOR/2768/2014). FCT also awarded a grant to J. Martín-García (SFRH/BPD/122928/2016).

Peer reviewed