New Delhi, Mar 17: Researchers from the Universidade de Lisboa have uncovered a promising ecological solution to combat anthracnose, a major fungal disease affecting almond (Prunus dulcis) production worldwide. The study, published in Agricultural Ecology and Environment (DOI: 10.48130/aee-0025-0015), highlights that almond trees host a rich and diverse fungal community, including native species capable of naturally suppressing the disease.
Anthracnose, which thrives in wet springs and moderate temperatures, can severely damage flowers, leaves, branches, and fruits, leading to sunken lesions, fruit mummification, and significant yield losses. Traditionally, control depends on preventive fungicide applications, but widespread chemical use raises environmental concerns, disrupts beneficial microbiota, and promotes resistant pathogen strains.
The research team conducted a comprehensive survey of fungal communities across 16 almond cultivars, collecting tissues from flowers, leaves, branches, and fruits. They identified 19,802 isolates across 39 genera, with branches producing the highest number of isolates and fruits showing the highest endophytic colonization. Alternaria, Cladosporium, Rhizopus, Penicillium, and Trichoderma were the dominant genera, while certain fungi were specific to either disinfected or non-disinfected tissues, indicating ecological specialization.
To evaluate biocontrol potential, 24 representative isolates were tested against Colletotrichum godetiae, the pathogen causing anthracnose. Trichoderma viridescens, Neurospora intermedia, and Trichoderma citrinoviride demonstrated exceptional antagonistic activity, inhibiting mycelial growth by up to 91.6% and reducing conidia production by over 99%. Other species, including Stemphylium vesicarium, Talaromyces amestolkiae, and Clonostachys chloroleuca, effectively suppressed sporulation, revealing diverse mechanisms of pathogen suppression.
The study concludes that almond orchards harbor a rich reservoir of native fungal antagonists that can serve as natural defense agents against anthracnose. Leveraging these endophytic species as biofungicides offers a sustainable alternative to chemical treatments, protecting beneficial microbiota and supporting resilient almond production systems.
This research represents a significant step toward microbiome-based crop protection, offering growers innovative, environmentally responsible tools to safeguard high-value nut crops while reducing reliance on synthetic fungicides.
