Abstract
Application of lime to a carrot field soil significantly reduced the incidence of cavity spot disease on carrots. It also increased soil microbial activity and the number of colony forming units (cfu) of aerobic bacteria, fluorescent pseudomonads, Gram negative bacteria actinomycetes and significantly decreased the cfu of filamentous fungi and yeast. Liming also increased the cfu of nonstreptomycete actinomycetes. These were isolated using polyvalent Streptomyces phages and the dry heat technique to reduce the dominance of streptomycete actinomycetes on isolation plates. The species isolated included Actinoplanes, Micromonospora, Streptoverticillium, Nocardia, Rhodococcus, Microbiospora, Actinomadura, Dactylosporangium and Streptosporangium. The numbers of actinomycetes antagonistic to P. coloratum increased in soil amended with lime.