ABSTRACT
This chapter describes the suppressive effect of NB22 on the occurrence of crown and root rot and bacterial wilt of tomato caused by F. oxysporum and P. solanacearum. The experiment was planned to assess the effect of the amendment of organic matter to soil. The combination of NB22 treatment with steam sterilization was an effective method to suppress the disease of crown and root rot of tomato. Several methods have been demonstrated to utilize NB22 to draw its potentiality as an agent of biological control. Various types of composts have been developed with the specific effects of antagonism, competition, parasitism, elicitation of plant defense responses, or plant growth promotion. As for microbial antagonism, B. subtilis, which was isolated from compost, produces an antifungal peptide, iturin A and has a wide range of antifungal and antibacterial activities that can be used as a prominent biological control agent.
