RESEARCH & EVENTS
Lessons in pathology and almond production from Spain and Portugal
Hedge-pruned almond trees in Portugal.
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By Brittany Oswald IN May this year, I joined 20 Australian delegates on a tour of almond production regions in Spain and Portugal. This trip was valuable from the perspective of a plant pathologist. Although the tour covered a range of topics, the high disease pressure, shifting EU regulations and evolving management strategies were highlighted, and may inform Australia’ s approach to future challenges concerning invasive pests and production constraints. Hedge pruning, high- and superhigh-density orchard plantings were a major focus. These systems were promoted for their potential to improve water-use and chemical-use efficiency. Smaller canopies allowed
In A Nutshell- Spring 2025 Vol 26 Issue 3
better airflow and spray coverage, reportedly reducing fungal disease incidence and severity. However, both systems involve higher orchard establishment costs and more ongoing pruning requirements than conventional systems. These practices were controversial and were not suitable for every grower. The importance of tailoring orchard design and management practices to local conditions was highlighted. Pathogen populations and disease pressures also differed markedly between regions. In Australia, hull rot is the main concern according to census results and disease surveys, while in Mediterranean orchards, anthracnose is the primary yieldlimiting disease. Constriction canker caused by Diaporthe amygdali also poses significant concern. The presence of red leaf blotch( Polystigma amygdalum) and almond leaf scorch( Xylella fastidiosa) in parts of Europe serves as a reminder of potential threats to Australia’ s biosecurity. Observing the management practices applied for these diseases, including welltimed sprays, and quarantine and eradication practices, offers valuable insight should an incursion occur in Australia. Following the tour, I worked in the laboratory of Professor Carlos Agustí- Brisach at the University of Córdoba( southern Spain). As part of project AL22002, we compared
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