scholarly journals Preliminary experiments into the use of Streptomyces spp. isolated from peat in the biological control of soil and seed-borne diseases in peat culture 

1982 ◽  
Vol 54 (5) ◽  
pp. 357-369 ◽  
Author(s):  
Risto Tahvonen
Keyword(s):  
Biological Control ◽  
Sugar Beet ◽  
Fusarium Culmorum ◽  
Fine Sand ◽  
Alternaria Brassicicola ◽  
Foot Rot ◽  
Damping Off ◽  
Sand Soil ◽  
Seeding Layer ◽  
Streptomyces Spp

Streptomyces spp. isolates obtained from peat effectively inhibited the growth of Alternaria brassicicola Wiltshire, Fusarium culmorum (W. G. Smith) Sacc., F. sulphureum Schlechtendahl, Pythium debaryanum auct. non Hesse and Rhizoctonia solani Kühn on PDA medium, but Streptomyces spp. isolates from fine sand soil were not effective against F. culmorum compared to the strains isolated from peat. Treatment of cauliflower seeds with Streptomyces spp. isolated from peat effectively controlled damping-off caused by A. brassicicola and R. solani when the seedlings were grown on either disinfected or fresh peat. Spraying the seeding layer of the peat substrate with a suspension of Streptomyces reduced the mortality of barley sprouts and foot rot caused by F. culmorum, and damping-off on sugar beet caused by P. debaryanum.

scholarly journals The biological control of seed-borne Alternaria brassicicola of cruciferous plants with a powdery preparation of Streptomyces sp.

1987 ◽  
Vol 59 (3) ◽  
pp. 199-208 ◽  
Author(s):  
Risto Tahvonen ◽  
Hanna Avikainen
Keyword(s):  
Biological Control ◽  
Brassica Species ◽  
Fine Sand ◽  
Alternaria Brassicicola ◽  
Damping Off ◽  
Streptomyces Sp ◽  
Seed Dressing ◽  
Dry Conditions ◽  
Cruciferous Plants ◽  
Different Origin

The effectiveness of a powdery preparation of a Streptomyces sp. isolate as a seed dressing agent against seed-borne Alternaria brassicicola on different Brassica species was investigated in the study. The preparation was made by freeze-drying and milling the biomass produced in a fermentor into a form suitable for use as a dusting agent. Seed dressing was 80—90 % successful in controlling damping-off from seeds artificially infected with A. brassicicola. The effectiveness of dressing remained unchanged on seeds stored under dry conditions for 5—6 weeks, but subsequently decreased slowly and was ca. 50 % six months after dusting. Streptomyces dressing controlled, in a manner comparable to chemical dressing with thiram, damping-off caused by Alternaria fungi on seedlings which were grown from commercial seed lots of different origin. The results of biological control of damping-off did not vary in the peat lots of different origin whose natural disease suppressivity varied considerably. The control result was the same or better than chemical dressing with thiram. The acidity of the substrate (pH 4.8—8.6) had no effect on the effectiveness of biological control. The results obtained against Alternaria damping-off were the same in other substrates clay, fine sand and mull as in peat.

Biological control of damping-off of sugar-beet and cotton with Chaetomium globosum or a fluorescent Pseudomonas sp.

1988 ◽  
Vol 34 (5) ◽  
pp. 631-637 ◽  
Author(s):  
D. Walther ◽  
D. Gindrat
Keyword(s):  
Biological Control ◽  
Sugar Beet ◽  
Seed Treatment ◽  
Pythium Ultimum ◽  
Chaetomium Globosum ◽  
Pseudomonas Sp ◽  
Damping Off ◽  
Antifungal Metabolites ◽  
Fluorescent Pseudomonas

Seed treatment with ascospores of Chaetomium globosum reduced damping-off of sugar-beet caused by seed-borne Phoma betae and soil-borne Pythium ultimum or Rhizoctonia solani in growth chamber experiments. Seed treatment with a fluorescent Pseudomonas sp. controlled Ph. betae and P. ultimum but not R. solani. Coating cotton seeds with ascospores controlled P. ultimum and R. solani damping-off. In some experiments, biological seed treatments were equally or more effective than seed treatment with captan. However, greater variability in disease control occurred with the antagonists than with captan. Fifty percent of freshly harvested ascospores of C. globosum germinated in 8 h on water agar. When ascospores were stored under air-dried conditions for 3 days to 2.5 years, germination increased to > 90%. Under same storage conditions, survival of Pseudomonas sp. was detected after 4 months. Antagonistic activities observed in vitro were hyphal coiling of C. globosum on R. solani, and mycostasis was induced by C. globosum or Pseudomonas sp. on agar and soil. The presumed cause of mycostasis is the diffusible antifungal metabolites which may also be involved in the biological control of damping-off.

scholarly journals Biological control of cucumber and sugar beet damping-off caused by Pythium ultimum with bacterial and fungal antagonists

2002 ◽  
Vol 92 (6) ◽  
pp. 1078-1086 ◽  
Author(s):  
D.G. Georgakopoulos ◽  
P. Fiddaman ◽  
C. Leifert ◽  
N.E. Malathrakis
Keyword(s):  
Biological Control ◽  
Sugar Beet ◽  
Pythium Ultimum ◽  
Damping Off
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