TY - GEN

T1 - Wine Yeast as Potential Biological Control Agent Against Downy Mildew of Grapevine (Plasmopara viticola)

AU - Behrendt, Rikke Adelsten

AU - Toldam-Andersen, Torben

AU - Arneborg, Nils

AU - Collinge, David B.

AU - Jensen, Birgit

N1 - Conference code: 21

PY - 2024

Y1 - 2024

N2 - Organic fruit growing still depends heavily on the use of copper-based fungicides. One of the most prominent examples of destructive diseases is downy mildew of grapevine. To avoid the environmental impact of copper accumulation, sustainable alternatives for preventing downy mildew epidemics are needed, such as biological control agents (BCAs). Yeasts are fierce competitors in natural systems and represent promising candidates as BCAs. In this study, greenhouse trials were carried out to test the efficacy of three strains of yeast against P. viticola, namely, Pichia kluyveri A, P. kluyveri B, and Saccharomyces cerevisiae S101. A novel leaf-fertiliser Aqua-Hort® was also tested. This contains a copper microdose that could reduce pollution with copper. All yeasts and the copper treatment reduced disease severity of downy mildew significantly when applied once before inoculation with P. viticola sporangia. The highest efficacy was obtained with copper. Moreover, application of P. kluyveri B reduced the number of indigenous fungi in the phyllosphere of grapevines significantly, compared to S. cerevisiae. The results indicate fungal interactions and a putative killer activity by P. kluyveri. Conclusively, indigenous grapevine yeast showed potential as a BCA against P. viticola.

AB - Organic fruit growing still depends heavily on the use of copper-based fungicides. One of the most prominent examples of destructive diseases is downy mildew of grapevine. To avoid the environmental impact of copper accumulation, sustainable alternatives for preventing downy mildew epidemics are needed, such as biological control agents (BCAs). Yeasts are fierce competitors in natural systems and represent promising candidates as BCAs. In this study, greenhouse trials were carried out to test the efficacy of three strains of yeast against P. viticola, namely, Pichia kluyveri A, P. kluyveri B, and Saccharomyces cerevisiae S101. A novel leaf-fertiliser Aqua-Hort® was also tested. This contains a copper microdose that could reduce pollution with copper. All yeasts and the copper treatment reduced disease severity of downy mildew significantly when applied once before inoculation with P. viticola sporangia. The highest efficacy was obtained with copper. Moreover, application of P. kluyveri B reduced the number of indigenous fungi in the phyllosphere of grapevines significantly, compared to S. cerevisiae. The results indicate fungal interactions and a putative killer activity by P. kluyveri. Conclusively, indigenous grapevine yeast showed potential as a BCA against P. viticola.

M3 - Article in proceedings

SP - 51

EP - 57

BT - Proceedings of the 21st International Conference on Organic Fruit- Growing

T2 - International Conference on Organic Fruit-Growing 2024

Y2 - 19 February 2024 through 21 February 2024

ER -