拮抗能を持つ放線菌を利用したフザリウム病害の抑制 : (第3報) 異なる土壌環境条件における微生物資材の土壌微生物相への影響とダイコン萎黄病に対する効果的施用法の検討

Control of Fusarium disease using antagonistic actinomycetes : 3. Effect of a microbial inoculum (material A) on microbial flora under some soil environmental conditions and development of effective method of application to radish yellows

Creators Takaki Shigeki

Creators Kitamura Akira

Creators Marumoto Takuya

Creators Ishida Daisaku

Creators Tanaka Shuhei

We developed a microbial inoculum (Material A) which contains 5 Actinomycetes isolates antagonistic against Fusarium oxysporum with an organic career. The career material was able to promote the activity of Actinomycetes in soil (Soil Microorganisms 38 : 41-48, 1992). In the present paper, the effects of the inoculum (Material A) on the soil microbial flora were investigated in relation to soil environmental conditions such as pH (pH5.3, 7.0, and 7.8), moisture level (MWHC20-80%), and temperature (20, 30, and 40℃). The application of the inoculum resulted in a high population density of Actinomycetes in soil irrespective of environmental factors, unless the soil moisture level was very low (20% MWHC). An effective method of application was also examined for controling radish yellows caused by Fusarium oxysporum f. sp. raphani. When radish plants were grown in soil infested with the pathogen, amendment of soil with the inoculum (Material A) decreased the desease severity. Especially, when the inoculum was applied to sterilized soil one week before the introduction of the pathogen and one or two weeks before the seeding of radish plants, the disease was almost completely suppressed. Continuous application of the inoculum (Material A) as well as that of crab shell seemed to promote the suppressive effect against the disease. The present results suggest that the microbial inoculum (Material A) suppressed radish yellows under various soil conditions and its effectiveness may be enhanced by the improvement of the method of application to soil.

[ISSN]0912-2184

[NCID]AN00352796