What does this research mean for the field?

Bacterial biocontrol treatments significantly reduce lesion severity caused by Botryosphaeria dieback in Vitis vinifera, with efficacy influenced by tissue type and season. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.SUPPORTS_CONSENSUS.

What question did this study set out to answer?

The aim is to evaluate the pathogenicity of Botryosphaeria species and the efficacy of bacterial biocontrol under different seasonal and tissue conditions.

March 1, 2026Open Access

Seasonal Effects on Pathogenicity and Biocontrol Management of Botryosphaeria in Vitis vinifera L. cv. Cabernet Sauvignon and Sauvignon Blanc Under Field Conditions

Key Points

The aim is to evaluate the pathogenicity of Botryosphaeria species and the efficacy of bacterial biocontrol under different seasonal and tissue conditions.
Field evaluation of pathogenicity and biocontrol efficacy in Vitis vinifera cultivars
Analysis of tissue types (young shoots and lignified arms) across seasons (autumn/winter and spring/summer)
Assessment of lesion development and biocontrol using native bacterial strains
Comparison of bacterial treatments with traditional fungicides
N. parvum exhibited more aggression in young shoots, while D. seriata caused severe lesions in lignified wood.
Higher lesion development was observed during spring/summer, particularly for N. parvum.
Biocontrol treatments significantly reduced lesion severity, especially in lignified arms.
Some bacterial strains matched or surpassed the effectiveness of the fungicide tebuconazole under high disease pressure.

Abstract

Grapevine trunk diseases, particularly Botryosphaeria dieback, pose a major threat to vineyard sustainability, a risk that is further intensified by climate variability and increasing environmental stress. This study evaluated pathogenicity and bacterial biocontrol efficacy against Neofusicoccum parvum and Diplodia seriata under vineyard conditions, analyzing the combined effects of cultivar (Vitis vinifera L. cv. Cabernet Sauvignon and Sauvignon Blanc), tissue type (young shoots and lignified arms), and phenological season (autumn/winter and spring/summer). Pathogenicity assays revealed clear tissue-age specialization: N. parvum was more aggressive in young shoots, whereas D. seriata caused the most severe vascular lesions in lignified wood. Seasonality further modulated disease expression, with higher lesion development during spring/summer, particularly for N. parvum in young shoots, while D. seriata maintained high aggressiveness in lignified tissues across both seasons. Berry assays provided a rapid initial assessment of isolate virulence but did not fully reflect pathogen behavior in woody tissue under field conditions. Biological treatments using native bacterial strains (Pseudomonas sp. AMCR2b, GcR15a, and Rhodococcus sp. PU4) significantly reduced lesion severity in V. vinifera under field conditions, although efficacy varied by tissue type and season. Biocontrol effects were generally more stable in lignified arms, and under high disease pressure, only the most robust strains maintained consistent protection, in some cases matching or surpassing the efficacy of the fungicide tebuconazole. These results show that both pathogenicity and biocontrol performance against Botryosphaeria dieback in V. vinifera under field conditions are strongly influenced by tissue type and season, supporting bacterial biocontrol as a sustainable component of integrated disease management in vineyards.

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