Effectiveness and Compatibility of Bacillus and Trichoderma in Increasing Disease Tolerance of Garlic to Basal Rot Caused by Fusarium oxysporum f.sp. cepae

Abstract

The main obstacle to garlic cultivation is the attack of Fusarium oxypsorum f. sp. cepae (FOCe) causes basal rot. Bacillus and Trichoderma are popular antagonist microorganisms that can act as biological control agents (BCA). This paper would like to report on the effectiveness and compatibility of Bacillus sp. and Trichoderma sp. as a biological control of basal rot of garlic based on laboratory and Greenhouse tests. The results of in vitro studies show that Bacillus and Trichoderma are potential antagonist agents through antibiosis and even Trichoderma through competition. Meanwhile, in vivo, the two biological control agents were not effective in reducing wilting intensity but effective in reducing basal rot intensity and increasing disease tolerance. Increasing disease tolerance is showed by the yield that is higher significantly than those control with no BCA. Bacillus sp. and Trichoderma sp. have been shown to be incompatible BCA based on both in vitro and in vivo tests, which are indicated by the effectiveness of the combination application being less effective than alone.

Suppressing pathogenic fungi associated with stored garlic bulbs causing cloves rot and decreasing disease development during storage by Bacillus subtilis and Trichoderma harzianum

“…However, T. harzianum isolates were more effective than isolates of B. subtilis. Such positive effects could be to the antagonistic activity of these bioagents against Fo and Fp, which were also similar to those stated by Ahir andMaharshi (2008), El-Babley, Hala (2012), Bjelić et al (2018), andPoromarto et al (2021), who applied the same bioagents on onion and/or garlic against Fusarium spp. and other fungal pathogens causing basil rot, black mold, and neck rot diseases in the field and storage.…”

“…The inhibitory effect of B. subtilis or T. harzianum against Fo and Fp could be attributed to the antibiotics and/or toxic substances secreted by these bioagents, limiting and inhibiting the fungal growth. Such results and others concerning the mode of action of these antagonistic bioagents were also reported by Samsudin and Magan (2016), Elshahawy et al (2017), Bjelić et al (2018), Poromarto et al (2021).…”