The widespread dependence on synthetic fungicides to manage this pathogen has raised mounting concerns over environmental impacts and the emergence of resistant strains. In response, the researchers uncovered that almond trees host a rich and diverse fungal community, including native species capable of naturally suppressing the disease, pointing toward more sustainable and ecologically sound management strategies.
Almond (Prunus dulcis) is a high-value nut crop widely grown in the United States, Spain, Australia, Türkiye, and Morocco. Intensified production systems, including irrigation and high-density planting, have increased vulnerability to fungal diseases, particularly anthracnose. This disease, favored by wet springs and temperatures of 20–25 °C, infects flowers, leaves, branches, and young fruits, causing sunken lesions, fruit mummification, and significant yield losses. Control mainly depends on preventive fungicide applications during flowering and early fruit set. However, chemical strategies may disrupt beneficial microbiota, leave residues, and promote resistant pathogen strains, driving interest in sustainable biological control alternatives.
A study (DOI:10.48130/aee-0025-0015) published in Agricultural Ecology and Environment on 20 January 2026 by Madalena Ramos & Pedro Talhinhas, Universidade de Lisboa, reveals that native almond-associated fungi can serve as effective biological control agents against anthracnose, providing a sustainable alternative to chemical fungicides and advancing microbiome-based crop protection strategies.
Using a comprehensive isolation and screening approach, researchers first characterized the fungal communities associated with almond trees by collecting flowers, leaves, branches, and fruits from 16 cultivars and processing tissues with and without surface disinfection to distinguish endophytes from epiphytes. This strategy yielded 19,802 isolates, including 12,211 endophytes and 7,591 combined epiphytic/endophytic isolates, grouped into 39 genera across Ascomycota, Basidiomycota, and Mucoromycota. Colonization patterns varied by organ and cultivar: branches produced the highest number of isolates (6,015), fruits showed the highest endophytic colonization frequency (92.8%), and leaves and branches exhibited the greatest endophytic diversity (Shannon index up to 2.25). Cultivars ‘Lauranne’, ‘Soleta’, and ‘Belona’ harbored the richest and most diverse communities. Across both disinfection methods, Alternaria was the dominant genus, followed by Cladosporium, Rhizopus, Penicillium, and Trichoderma, while certain genera were exclusive to either disinfected or non-disinfected tissues, indicating ecological specialization. To evaluate biocontrol potential, 24 representative isolates were tested against Colletotrichum godetiae in dual culture assays. The results revealed striking differences in antagonistic capacity: Trichoderma viridescens, Neurospora intermedia, and Trichoderma citrinoviride achieved the highest mycelial inhibition (up to 83.69% on average and 91.61% at the final assessment), with T. viridescens reducing conidia production by 99.31% and rapidly overgrowing the pathogen. Two-way ANOVA confirmed significant effects of isolate identity and time on inhibition dynamics (p < 2 × 10⁻¹⁶). Some isolates, including Stemphylium vesicarium, Talaromyces amestolkiae, and Clonostachys chloroleuca, strongly suppressed sporulation (>92%) despite limited effects on colony growth, indicating distinct mechanisms targeting conidiogenesis. In contrast, certain Penicillium, Cladosporium, and Diaporthe isolates stimulated pathogen sporulation, producing more conidia than controls. Macroscopic observations further revealed diverse interaction types, including overgrowth, contact inhibition, distance inhibition, and mycelial replacement, highlighting the complexity of fungal–fungal interactions within the almond microbiome.
In conclusion, this study demonstrates that almond orchards possess a rich reservoir of native fungal antagonists that can function as natural defense agents against anthracnose. Endophytic species such as Trichoderma viridescens, T. citrinoviride, and Neurospora intermedia show strong potential as biofungicide candidates due to their adaptation to the host environment. Harnessing these fungi could reduce chemical inputs, protect beneficial microbiota, and promote more sustainable, resilient almond production systems.
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References
DOI
10.48130/aee-0025-0015
Original Souce URL
https://doi.org/10.48130/aee-0025-0015
Funding information
This work was funded by FCT – Fundação para a Ciência e a Tecnologia, I.P. (Grant No. 2021.05854.BD), and FCT – Fundação para a Ciência e Tecnologia, I.P. through project UID/04129/2025 (https://doi.org/10.54499/UID/04129/2025) of LEAF-Linking Landscape, Environment, Agriculture, and Food.
About Agricultural Ecology and Environment
Agricultural Ecology and Environment (e-ISSN 3070-0639) is a multidisciplinary platform for communicating advances in fundamental and applied research on the agroecological environment, focusing on the interactions between agroecosystems and the environment. It is dedicated to advancing the understanding of the complex interactions between agricultural practices and ecological systems. The journal aims to provide a comprehensive and cutting-edge forum for researchers, practitioners, policymakers, and stakeholders from diverse fields such as agronomy, ecology, environmental science, soil science, and sustainable development.