Biological control of seedling damping-off and root rot of sugar beet plants

Abstract

Some fungal and bacterial bioagents as well as an Actinomycete isolate were screened for their antagonistic effects against S. rolfsii, R. solani, M. phaseolina, F. oxysporum and F. solani in vitro. Trichoderma hamatum, T. harzianum, T. pseudokningii, certain isolates of Bacillus subtilis and one isolate of Pseudomonas fluorescens were the most effective bioagents in suppressing the radial growth of the four pathogens, in general. Yet, they were less effective in retarding growth of Fusarium spp. as compared with the other pathogens under study. Studying biological control showed the possibility of controlling sugar beet damping-off and root rot by certain bioagents as T. hamatum, T. hazianum, Pseudomonas fluorescens and B. subtilis under greenhouse (S. rolfsii-infested soil) and field (natural infection) conditions. These treatments also caused and increase root yield per plot.