Use of Trichoderma harzianum and Gliocladium vitens for the Biological Control of Post-emergence Damping-off and Root Rot of Cucumbers Caused by Pythium ultimum

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.

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Biological Control of Damping-off of Cucumber caused by Pythium ultimum with a Root-Colonization-Deficient strain of Escherichia coli

Journal of Phytopathology ◽

10.1111/j.1439-0434.1997.tb00419.x ◽

1997 ◽

Vol 145 (8-9) ◽

pp. 383-388 ◽

Cited By ~ 19

Author(s):

D. P. Roberts ◽

P. D. Dery ◽

P. K. Hebbar ◽

W. Mao ◽

R. D. Lumsden

Keyword(s):

Escherichia Coli ◽

Biological Control ◽

Root Colonization ◽

Pythium Ultimum ◽

Damping Off

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Resistance of the Soybean Cultivar Archer to Pythium Damping-Off and Root Rot Caused by Several Pythium spp.

Plant Disease ◽

10.1094/pdis-92-5-0763 ◽

2008 ◽

Vol 92 (5) ◽

pp. 763-766 ◽

Cited By ~ 19

Author(s):

G. D. Bates ◽

C. S. Rothrock ◽

J. C. Rupe

Keyword(s):

Root Rot ◽

Seed Quality ◽

Developmental Stages ◽

Pythium Ultimum ◽

Soybean Cultivar ◽

Damping Off ◽

Maturity Group ◽

Group V ◽

Disease Symptoms ◽

Group I

Archer, a maturity group I soybean cultivar with demonstrated flood tolerance and resistance to Pythium ultimum, was compared with Hutcheson, a widely planted maturity group V cultivar in Arkansas, for resistance to P. ultimum, P. irregulare, P. aphanidermatum, P. vexans, and group HS. Emergence and establishment assays demonstrated that Archer had greater emergence and fewer disease symptoms after 10 days for all pathogenic species of Pythium than did Hutcheson. Archer also demonstrated higher root weights and fewer disease symptoms compared with Hutcheson in assays conducted for 6 weeks. Similar results were found using two different seed lots of the cultivars, suggesting that the results were not due to seed quality differences. This study indicates that resistance in Archer to Pythium damping-off and root rot compared with Hutcheson is robust, with efficacy over a number of Pythium spp. and a range of plant developmental stages.

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