Trichoderma tomentosum and T. Afroharzianum as potential biocontrol agents for white rot disease Sclerotium cepivorum berk of garlic in Ambo, Ethiopia

Abstract

Garlic (Allium sativum) is a favourite spice in Ethiopia that is widely cultivated and used as food and in medicine. This experiment was  carried out for seven months in 2007. Some Trichoderma species were isolated from the soil in infected Allium sativum farms in three  villages in Ambo, Ethiopia and identified. Internal transcribed spacer regions (ITS1-2) of rDNA and the translation elongation factor 1-α  (eEF1a1) were generated from the isolates obtained using an ABI Prism 3100 Genetic Analyzer (Applied Biosystems). The species of fungi  were further evaluated for their activity against Sclerotium cepivorum using Weller’s and dual culture methods. AS1, AST1 and GS2 were  identified as Trichoderma tomentosum, AS2 as Hypocrea lixii and GS1 as Trichoderma afroharzianum. AS1, AS2 and GS2 parasitised S.  cepivorum and inhibited the growth of the pathogen while ATS1 and GS1 parasitised the pathogen only. AS1 showed the strongest  significant antibiosis of 3.75 mm while the significantly least antibiosis was by GS2. GS1 showed 100% parasitism on the 7^th day of  incubation.  These Trichoderma species inhibited the growth of the pathogens and can be useful in the production of fungicide for the  control of white rot disease of garlic.