Control of avocado anthracnose by carposphere-associated Kosakonia cowanii VG1 for agricultural applications.

Abstract

Avocado anthracnose, a devastating fungal disease caused by Colletotrichum gloeosporioides and Colletotrichum acutatum, represents the most significant postharvest challenge for avocado production. This study evaluates the biocontrol potential of bacterial strains isolated from different niches within the avocado ecosystem, including fruits, roots, trunks and nectar. Among these isolates, the bacterium Kosakonia cowanii VG1, isolated from avocado carposphere, demonstrated the highest in vitro antagonistic activity, inhibiting mycelial growth and spore germination of both Colletrotrichum species by 70% and 65%, respectively. In vivo experiments with K. cowanii VG1 reduced disease severity by 60% in avocado fruits compared to untreated controls. Genomic analysis of K. cowanii VG1 revealed the absence of virulence factors, ensuring safety for human health. Additionally, fermentation analysis demonstrated that K. cowanii VG1 can be efficiently cultured at large scales. Additionally, a techno-economic evaluation showed that its production costs are competitive, ranging from $0.08-$0.15 per dose. These findings highlight the potential of K. cowanii VG1 as a promising, safe, and cost-effective biocontrol agent for managing avocado anthracnose, offering a sustainable alternative to synthetic fungicides.