Bio-priming Seed Treatment for Biological Control of Pythium ultimum Preemergence Damping-off in sh2 Sweet Corn

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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FIELD PERFORMANCE OF BIO-PRIMING FOR PROTECTION OF sh2 SWEET CORN FROM PREEMERGENCE DAMPING-OFF CAUSED BY PYTHIUM ULTIMUM.

HortScience ◽

10.21273/hortsci.25.9.1110f ◽

1990 ◽

Vol 25 (9) ◽

pp. 1110f-1110

Author(s):

Nancy W. Callan ◽

James B. Miller ◽

Don E. Mathre

Keyword(s):

Pseudomonas Fluorescens ◽

Seed Treatment ◽

Field Experiments ◽

Sweet Corn ◽

Seedling Emergence ◽

Field Performance ◽

Pythium Ultimum ◽

Damping Off ◽

Corn Seed ◽

Seed Bacterization

Shrunken-2 supersweet (sh2) sweet corn is susceptible to preemergence damping-off caused by Pythium ultimum, especially when planted into cold soil. Bio-priming, a seed treatment which combines the establishment of a bioprotectant on the seed with preplant seed hydration, was developed to protect seeds from damping-off.In a series of field experiments conducted in Montana's Bitterroot and Gallatin Valleys, bio-priming or seed bacterization with Pseudomonas fluorescens AB254 protected sweet corn from P. ultimum damping-off. Bio-priming corn seed with P. fluorescens AB254 was comparable to treatment with the fungicide metalaxyl in increasing seedling emergence. Seedlings from bio-primed seeds emerged from the soil more rapidly than from nontreated seeds and were larger at three weeks postplanting. Seeds of sh 2 and sugary enhancer (se) sweet corn, as well as that of several sh 2 cultivars, were protected from damping-off by bio-priming.

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Field Performance of Sweet Corn Seed Bio-primed and Coated with Pseudomonas fluorescens AB254

HortScience ◽

10.21273/hortsci.26.9.1163 ◽

1991 ◽

Vol 26 (9) ◽

pp. 1163-1165 ◽

Cited By ~ 29

Author(s):

Nancy W. Callan ◽

Don E. Mathre ◽

James B. Miller

Keyword(s):

Pseudomonas Fluorescens ◽

Seed Treatment ◽

Field Experiments ◽

Sweet Corn ◽

Field Performance ◽

Pythium Ultimum ◽

Seedling Height ◽

Damping Off ◽

Corn Seed ◽

Degree Of Protection

In field experiments, bio-priming and coating with Pseudomonas fluorescens AB254 consistently protected sweet corn (Zea mays L.) seeds from preemergence damping-off caused by Pythium ultimum Trow. The bio-priming seed treatment was evaluated under various disease pressures and with seeds of three sweet corn genotypes: shrunken-2 supersweet (sh-2), sugary enhancer (se), and sugary (su). While no damping-off occurred in the su sweet corn, bio-priming protected sh-2 and se sweet corn seeds at a level equivalent to that obtained by treatment with the fungicide metalaxyl. Biopriming increased seedling height of all three sweet corn genotypes at 4 weeks post-planting. Coating of sweet corn seeds with P. fluorescens AB254 provided an equivalent degree of protection from damping-off under all but the most severe conditions.

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Seed Treatment with Ethanol Extract of Serratia marcescens is Compatible with Trichoderma Isolates for Control of Damping-off of Cucumber Caused by Pythium ultimum

Plant Disease ◽

10.1094/pdis-09-15-1039-re ◽

2016 ◽

Vol 100 (7) ◽

pp. 1278-1287 ◽

Cited By ~ 5

Author(s):

Daniel P. Roberts ◽

Dilip K. Lakshman ◽

Laurie F. McKenna ◽

Sarah E. Emche ◽

Jude E. Maul ◽

...

Keyword(s):

Biological Control ◽

Disease Control ◽

Seed Treatment ◽

Sandy Loam ◽

Ethanol Extract ◽

Pythium Ultimum ◽

Damping Off ◽

Integrated Disease Control ◽

Loam Soil ◽

Trichoderma Isolates

Environmentally friendly control measures for soilborne plant pathogens are needed that are effective in different soils when applied alone or as components of an integrated disease control strategy. An ethanol extract of Serratia marcescens N4-5, when applied as a cucumber seed treatment, effectively suppressed damping-off caused by Pythium ultimum in potting mix and in a sandy loam soil. Plant stand associated with this treatment was similar to that of seed treated with the chemical pesticide Thiram in the sandy loam soil. The N4-5 ethanol extract did not consistently provide significant disease control in a loam soil. The N4-5 ethanol extract was compatible with two Trichoderma isolates, not affecting in vitro or in situ colonization of cucumber by these biological control fungi. Control of damping-off of cucumber was never diminished when this ethanol extract was applied as a seed treatment in combination with in-furrow application of the Trichoderma isolates, and disease control was improved in certain instances with these combinations in the loam soil. Data presented here indicate that the N4-5 ethanol extract is compatible with certain beneficial fungi, suggesting that this extract can be used as a component of integrated disease control strategies featuring biological control fungi.

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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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Epidemiology of Pythium Damping-off and Aphanomyces Root Rot of Peas After Seed Treatment with Bacterial Agents for Biological Control

Phytopathology ◽

10.1094/phyto-83-1466 ◽

1993 ◽

Vol 83 (12) ◽

pp. 1466 ◽

Cited By ~ 37

Author(s):

J. H. Bowers

Keyword(s):

Biological Control ◽

Root Rot ◽

Seed Treatment ◽

Damping Off

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Beneficial Effects of Solid Matrix Chemo-priming in Okra

Plant Disease ◽

10.1094/pdis.2001.85.5.535 ◽

2001 ◽

Vol 85 (5) ◽

pp. 535-537 ◽

Cited By ~ 2

Author(s):

K. E. Conway ◽

R. Mereddy ◽

B. A. Kahn ◽

Y. Wu ◽

S. W. Hallgren ◽

...

Keyword(s):

Untreated Control ◽

Seed Treatment ◽

Seedling Emergence ◽

Pythium Ultimum ◽

Field Trials ◽

Solid Matrix ◽

Damping Off ◽

Untreated Seed ◽

Beneficial Effects ◽

Emergence And Reduction

Two field trials at Stillwater and Bixby, OK, evaluated the efficacy of solid matrix priming techniques, alone or in combination with fungicide seed treatment on seedling emergence and reduction of damping-off of okra in field soil naturally infested with Pythium ultimum. The following treatments were evaluated: thiram + carboxin (chemo-primed) (commercially applied), biological seed treatment (bio-primed) (Trichoderma harzianum isolate OK-110, 1 g suspended in 1% carboxymethylcellulose [CMC]), untreated seed (control), and a 1% CMC control. Chemo-primed seeds had a more uniform and faster emergence compared with untreated seeds at both field sites. Within 3 days, 92 and 78% of chemo-primed seeds had emerged at Stillwater and Bixby, respectively, compared with 84 and 71% emergence in the untreated control. Mean emergence of chemo-primed seeds was lower (P ≤ 0.05) than the untreated control. Chemo-primed seeds had greater vigor (P≤ 0.05) at both locations compared with either fungicide-treated or priming alone, at both locations. There were no differences (P ≤ 0.05) in yield among treatments at both locations. P. ultimum was consistently isolated from damped-off seedlings and surrounding soil at both locations. Isolates of P. ultimum were more pathogenic on okra in laboratory tests than isolates of Rhizoctonia spp., Fusarium spp., and other Pythium spp. also isolated from seed or soil.

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

Journal of Applied Microbiology ◽

10.1046/j.1365-2672.2002.01658.x ◽

2002 ◽

Vol 92 (6) ◽

pp. 1078-1086 ◽

Cited By ~ 62

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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Seed Treatment Using Pre-infiltration and Biocontrol Agents to Reduce Damping-off of Corn Caused by Species of Pythium and Fusarium

Plant Disease ◽

10.1094/pdis.1998.82.3.294 ◽

1998 ◽

Vol 82 (3) ◽

pp. 294-299 ◽

Cited By ~ 33

Author(s):

W. Mao ◽

R. D. Lumsden ◽

J. A. Lewis ◽

P. K. Hebbar

Keyword(s):

Disease Control ◽

Plant Height ◽

Root Rot ◽

Seed Treatment ◽

Pythium Ultimum ◽

Biocontrol Agents ◽

Infested Soil ◽

Damping Off ◽

Fresh Weight ◽

Inoculum Rate

Bioassays were conducted in a greenhouse at 18°C to determine the effectiveness of a seed treatment used in combination with biocontrol agents for the reduction of corn damping-off caused by species of Pythium and Fusarium. Corn seeds were infiltrated with tap water, drained, air-dried, and then coated with biomass of an antagonistic fungus, Gliocladium virens isolate Gl-3, or an antagonistic bacterium, Burkholderia cepacia isolates Bc-B or Bc-1, or a combination of Gl-3 with each of the bacterial isolates. A nonsterile field soil was infested with a combination of pathogens: Pythium ultimum, P. arrhenomanes, and Fusarium graminearum at 2 inoculum rates (1× and 4×). Pre-infiltration enhanced (P ≤ 0.05) disease control with most treatments at both inoculum rates. Treatments with biocontrol agents alone or in combination, as well as the fungicide captan, effectively reduced the disease at a pathogen inoculum rate of 1×, resulting in greater (P ≤ 0.05) seedling stands, plant height, and fresh weight, and lower (P ≤ 0.05) root rot severity compared with untreated seeds in infested soil. At a pathogen inoculum rate of 4×, stands were lower (P ≤ 0.01) and root-rot severity was higher (P ≤ 0.01) compared to those at 1× for all treatments. Nevertheless, coating seeds with all biocontrol agents (alone or in combination), except with Bc-1 alone, reduced disease (P ≤ 0.05) compared to untreated seeds in infested soil. At both inoculum rates of 1× and 4×, coating seeds with Gl-3 + Bc-B was more effective (P ≤ 0.05) in disease control than any other treatment, resulting in stands, growth rate (plant height and fresh weight), and root rot severity similar to plants from untreated seeds in noninfested soil. In addition, when the exudate from a 2-h infiltration of corn seed was added to the seeds during seed coating, seedling stand was often lower and root rot severity was often higher than those from infiltrated seeds (P ≤ 0.05). These results indicated that the infiltration process removed certain exudates, including nutrients and/or stimulants (not detected in this study) that might be utilized by pathogens to initiate seed infection. A thin-layer chromatography (TLC) profile of the exudates showed the presence of eight amino acids and three major carbohydrates.

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Greenhouse Evaluation of Seed and Drench Treatments for Organic Management of Soilborne Pathogens of Spinach

Plant Disease ◽

10.1094/pdis-93-12-1281 ◽

2009 ◽

Vol 93 (12) ◽

pp. 1281-1292 ◽

Cited By ~ 18

Author(s):

Jaime A. Cummings ◽

Carol A. Miles ◽

Lindsey J. du Toit

Keyword(s):

Seed Treatment ◽

Pythium Ultimum ◽

Organic Production ◽

Compost Tea ◽

Damping Off ◽

Seed Treatments ◽

Greenhouse Study ◽

Greenhouse Evaluation ◽

Equivalent Control ◽

Bacillus Pumilis

The efficacy of 14 seed and drench treatments for control of soilborne damping-off pathogens in organic production of spinach was evaluated in a greenhouse study. The efficacy of each treatment was compared with nontreated seed and seed treated with a conventional fungicide for control of Fusarium oxysporum f. sp. spinaciae, Pythium ultimum, and Rhizoctonia solani. Two experimental seed treatments, GTG I and GTG II (each comprised of a proprietary organic disinfectant and the latter also containing Trichoderma harzianum T22), provided equivalent control to the conventional fungicide, mefenoxam, against P. ultimum in one trial and significant reduction of damping-off in the second trial. Natural II and Natural X (Streptomycete products), and Subtilex (Bacillus subtilis) seed treatments each suppressed damping-off significantly in one of the two trials. For R. solani, GTG I and Natural II seed treatments reduced damping-off as effectively as a drench with the fungicide Terraclor (pentachloronitrobenzene). A soil drench with Prestop (Gliocladium catenulatum) suppressed postemergence wilt caused by F. oxysporum in both trials; a compost tea drench and seed treatment with Yield Shield (Bacillus pumilis) each suppressed postemergence wilt in only one of two trials. GTG I and GTG II significantly increased seed germination compared to nontreated seed. No treatment was effective against all three pathogens, and some treatments exacerbated damping-off.

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