Abstract

ORTEGA-AGUILAR, Blanca Lilia; ALARCON, Alejandro  and  FERRERA-CERRATO, Ronald. Effect of potassium bicarbonate on fungai growth and sclerotia of Sclerotium cepivorum and its interaction with Trichoderma. Rev. Mex. Mic [online]. 2011, vol.33, pp.53-61. ISSN 0187-3180.

The effect of potassium bicarbonate (KHCO₃) as an antifungal agent was tested on the fungal growth of Sclerotium cepivorum and Trichoderma strain R39. The growth of the fungal colony, the number and germination of sclerotia formed by S. cepivorum, as well as the antagonism of Trichoderma on the pathogen were evaluated in potato dextrose agar (PDA, Baker^®) culture media amended with seven concentrations of KHCO (2, 4, 6, 8, 10, 3 25 and 50 mM). At 50 mM, the growth of S. cepivorum was inhibited 34.5%, whilst for Trichoderma inhibition was 83.1%. At the concentrations of 10, 25 and 50 mM of KHCO₃ sclerotia formation by S. cepivorum was significantly inhibited (51.5%, 77.0% and 100%, respectively), likewise the sclerotia germination (18%, 78% and 86%, respectively). When both fungi were confronted in a KHCO₃ -enriched PDA, this chemical compound did not affect the antagonistic capability of Trichoderma towards the pathogen. After 144 h, Trichoderma showed an invasion of 70% over the colony of S. cepivorum, at 50 mM. The potential benefits of KHCO to inhibit both growth and development of S. cepivorum were 3 evident, since it reduced either fungal growth or both formation and germination of sclerotia.

Keywords : antifungal compound; antagonism; plant pathogen; biocontrol.