The effect of inoculation of seed with antagonists of Rhizoctonia solani on the growth of wheat

Abstract

Biological control of Rhizoctonia solani on wheat by seed inoculation with microorganisms was investigated. Initially inoculants were selected from bacteria and actinomycetes isolated from two soils and screened for antagonism to R. solani on agar. Of 148 isolates tested on agar, 96 were antagonistic to R. solani and of these 42 were added to pasteurized soil sown with peppers and inoculated with the pathogen. Seven isolates which controlled disease were screened further as seed inoculants of wheat in pasteurized and field soils inoculated with R. solani. Four inoculants, viz. Streptomyces griseus 2-A24 and three Bacillus subtilis isolates 1-B80, 1-B77 and 1-B68, significantly reduced symptoms caused by R. solani and also increased grain yield and dry matter of wheat. S. griseus 2-A24 and B. subtilis 1-B80 increased grain yield by 30% over controls. The magnitude of these differences suggests that biological control and growth stimulation are involved in yield increases.

Biological Control of Damping-Off of Tomato Seedlings and Cucumber Phomopsis Root Rot by Bacillus subtilis RB14-C

“…In the present study of the pouring treatment of the RB14-C cell suspension, in which culture fluid containing iturin A was removed, iturin A could not be detected from the treated soil and, accordingly, the occurrence of damping-off of tomato seedlings caused by R. solani could not be suppressed even though high-densities of RB14-C cells were applied. On the contrary, seed treatment of RB14-C cells at the time of germination reduced the disease occurrence as reported by other studies 10,11 . In addition, the anti-rhizoctonial effect of flutolanil was enhanced by the simultaneous application of the RB14-C cell suspension and the use of germinated seeds pre-treated with RB14-C cells.…”

Phytohormones and Antibiotics Produced by Bacillus subtilis and their Effects on Seed Pathogenic Fungi and on Soybean Root Development

“…The inhibitory effect of Bacillus subtilis on plant pathogenic fungi has been frequently reported in laboratory, greenhouse, and field studies (Merriman et al 1974;Pusey & Wilson 1984;Cubeta et al 1985;Bettiol & Kimati 1990;Bettiol et al 1994;Melo 1998). B. subtilis is able to synthesize more than 60 different types of antibiotics, mainly polypeptides, many of which possessing antifungal effects and belonging to the iturin family (Phae & Shoda 1991).…”

Biological control of Rhizoctonia solani on potatoes by antagonists. 1. Preliminary experiments with Verticillium biguttatum, a sclerotium-inhabiting fungus

“…Price et al (1971) treated seeds of wheat, oats and barley with Bacillus subtilis against Rhizoctonia, Pythium and Fusarium, and thus obtained higher yields. Merriman et al (1974) were able to reduce symptoms of R. solani in wheat substantially by inoculating the seed with Streptomyces griseus or Bacillus subtilis. In cotton, Howell and Stipanovic (1979) obtained effective protection against R. solani by treating seeds with Pseudomonas fluorescens.…”