Site factors and management practices associated with the incidence of blight in chestnut orchards in Northeastern Portugal

• Autor(a) principal: Portela, Ester
• Data de Publicação: 2005
• Outros Autores: Pinto, Rui
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10348/8708
• topic: Chestnut; Blight; Castanea sativa; Northeastern Portugal; Cryphonectria parasitica

The objective of this study was to identify the possible relationship between management practices and site factors with the incidence of blight in chestnut orchards. The survey took place in the two ecological sub-regions of Padrela and Bragança in NE Portugal. A total of 62 farmers were questioned about management practices and 107 orchards were described for site characteristics and evaluated for blight disease. Statistical analyses were carried out both for discrete and continuous variables in order to determine the association between these and the presence of disease in healthy orchards (< 10% of incidence) and diseased orchards (> 10% incidence). Chestnut blight occurs more often in orchards located in soils derived from granite and quartzite schist, on plateau and convex slopes and in orchards established on previously uncultivated land (moorland). No relationship was found between disease incidence and slope aspect, soil drainage or soil stoniness. The blight incidence was higher in orchards submitted to more tillage operations (≥3 per year); less frequent pruning (3-4 years, i. e. larger branches) when compared to more frequent pruning (1-2 years, i. e. twigs); heavy application of farmyard manures; higher N and P application rates both from organic and mineral fertilisers.