Spatial and temporal analysis of Phytophthora megakarya epidemic in newly established cacao plantations
| Autor: | Christian Cilas, Claire Neema, Marie-Ange Ngo Bieng, Minette Mireille Ndoungue Djeumekop, François Bonnot, Gerben Martijn Ten Hoopen, Fabienne Ribeyre |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
Phytophthora Phytophthora megakarya Plantations Plant Science Disease distribution 01 natural sciences Maladie des plantes Theobroma cacao analyse spatiale H20 - Maladies des plantes Preventive strategy biology U10 - Informatique mathématiques et statistiques Disease progression 04 agricultural and veterinary sciences biology.organism_classification Plant disease Agronomy Modélisation 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Biological dispersal Infection dynamics Agronomy and Crop Science épidémie 010606 plant biology & botany |
| Zdroj: | Plant Disease |
| Popis: | Studying spatial and temporal plant disease dynamics helps us to understand pathogen dispersal processes and improve disease control recommendations. In this study, three cacao plots devoid of primary inoculum of Phytophthora megakarya (causal agent of cacao black pod rot disease) upon establishment in 2006 were monitored for presence of disease on a weekly basis from 2009 to 2016. Ripley’s K(r) function, join count statistics, and Fisher’s Exact test were used to analyze spatial and temporal disease dynamics. Disease distribution maps showed aggregated disease patterns in all plots; however, for the years of disease onset, exogenous primary infections were mostly randomly distributed. The K(r) function confirmed these results indicating that inoculum generally disperses only over short distances. Moreover, significant positive spatial autocorrelations showed that diseased trees were often clustered up to a distance of 3 to 9 m. Temporal disease progression was low, meaning that endogenous inoculum failed to establish itself, which is partly explained by rigorous phytosanitation and partly by unfavorable microclimatic conditions for disease development. Because P. megakarya had difficulty establishing itself in the plots, proximity to already infected cacao plantations drove infection dynamics. Thus, isolation of newly established cacao plantations from infected ones and rigorous phytosanitation as a preventive strategy appears to be an effective approach to control cacao black pod rot disease for newly established cacao plantations. |
| Databáze: | OpenAIRE |
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