Effect of Rooibos and Honeybush Tea Extracts Against Botrytis cinerea

  • G. Coetzee Department of Microbiology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
  • I.J. Marx Department of Microbiology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
  • M. Pengilly Department of Microbiology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
  • V.S. Bushula Department of Microbiology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
  • E. Joubert Post-Harvest & Wine Technology Division, ARC Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch 7599, South Africa
  • M. Bloom Department of Microbiology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa

Abstract

Green tea extracts from the indigenous South African rooibos (Aspalathus linearis) and honeybush (Cyclopia species)
plants were evaluated as potential antifungal agents against the plant pathogen Botrytis cinerea. When applied at 10
mg/ml, the tea extracts stimulated biomass production in B. cinerea by more than 3-fold after 24 hrs. This induction
could not be linked directly to the presence of selected micro- and macronutrients or antioxidants in the extracts,
suggesting a complex set of yet unidentified factors that may act synergistically to enhance cell growth. However,
when applied at 100 mg/ml, the A. linearis and C. genistoides extracts reduced spore germination of B. cinerea by
33.3% and 16.7%, respectively. This suggests that the tea extracts contain active compounds that should be further
investigated for their potential as natural anti-fungal agents.
Published
2016-12-13
Section
Articles