LOW CARBON AMENDMENT RATES DURING ANAEROBIC SOIL DISINFESTATION (ASD) AT MODERATE SOIL TEMPERATURES DO NOT DECREASE VIABILITY OF SCLEROTINIA SCLEROTIORUM SCLEROTIA OR FUSARIUM ROOT ROT OF COMMON BEAN

Experiments were conducted to evaluate potential functional and mechanistic differences in the suppression of Sclerotinia sclerotiorum and S. minor and root-knot nematodes in muck soils by anaerobic soil disinfestation (ASD) using different carbon source amendments. Volatile compounds produced during ASD in muck soil amended with molasses, wheat bran, or mustard greens at 20.2 Mg/ha or a 2% ethanol solution significantly reduced the mycelial growth and number of sclerotia produced by both Sclerotinia spp. compared with the anaerobic control. In amended soils, acetic and butyric acids were detected in concentrations that reduced the viability of sclerotia of both pathogens. Higher concentrations of carbon dioxide were observed in ASD-treated soils, regardless of the amendment, than in the nonamended anaerobic control. Only amendment with wheat bran did not increase the production of methane gas during ASD compared with the controls. Meloidogyne hapla survival was completely suppressed in soils treated with ASD regardless of carbon source. Field trials were conducted in Ohio muck soil to assess survival of sclerotia of both Sclerotinia spp. The viability of sclerotia of both Sclerotinia spp. was significantly reduced in soil subjected to ASD amended with wheat bran (20.2 Mg/ha), molasses (10.1 Mg/ha), or wheat bran (20.2 Mg/ha) plus molasses (10.1 Mg/ha) compared with the controls. A consistent negative correlation between soil reduction and viability of sclerotia of both pathogens was observed. Wheat bran and molasses are both widely available amendments that can be used as ASD carbon sources for the management of soilborne pathogens in muck soils.

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Anaerobic soil disinfestation efficacy against Fusarium oxysporum is affected by soil temperature, and amendment type, rate and C:N ratio

Phytopathology ◽

10.1094/phyto-07-20-0276-r ◽

2020 ◽

Author(s):

Utsala Shrestha ◽

Bonnie H. Ownley ◽

Alexander Bruce ◽

Erin N. Rosskopf ◽

David Michael Butler

Keyword(s):

Soil Temperature ◽

Fusarium Oxysporum ◽

Wheat Bran ◽

Meta Analysis ◽

C:N Ratio ◽

Organic Amendments ◽

Field Studies ◽

Soil Disinfestation ◽

Anaerobic Soil Disinfestation ◽

Soil Temperatures

A meta-analysis of anaerobic soil disinfestation (ASD) efficacy against Fusarium oxysporum (Fo) and Fo f. sp. lycopersici (Fol) was conducted emphasizing effects of environment and organic amendment characteristics, and pot and field studies conducted on ASD amendment C:N ratio and soil temperature effects on Fol inoculum survival. In a pot study, two organic amendments, dry molasses-based or wheat bran-based applied at 4 mg C/g soil, with 40:1, 30:1, 20:1, and 10:1 C:N ratios, were evaluated against Fol at 15-25°C. This was followed by a pot study at temperature regimes of 15-25°C and 25-35°C, and two C:N ratios (20:1 and 40:1), and a field study at 40:1, 30:1, 20:1, and 10:1 C:N ratios, 30:1 C:N ratio at lower C rate (2 mg C/g soil), and an anaerobic control. Soil temperature above 25°C, and more labile amendments, increased ASD suppression of Fo/Fol in the meta-analysis. In pot studies, Fol survival was reduced for molasses-based mixtures at 20:1 and 30:1 C:N ratios, compared to wheat bran-based, but not compared to the anaerobic control. At 25-35°C, all ASD treatments suppressed Fol relative to controls. In the field, all ASD treatments reduced Fol survival compared to the anaerobic control, and 4 mg C/g soil amendment rates induced increased anaerobic conditions and higher Fol mortality compared to the 2 mg C/g soil rate. While amendment C:N ratios from 10 to 40:1 were similarly suppressive of Fo, lower temperatures reduced ASD effectiveness against Fo/Fol and further work is warranted to enhance suppression at soil temperatures below 25°C.

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On-farm evaluations of anaerobic soil disinfestation and grafting for management of a widespread soilborne disease complex in protected culture tomato production

Phytopathology ◽

10.1094/phyto-07-20-0288-r ◽

2020 ◽

Author(s):

Anna Louise Testen ◽

Marlia Bosques Martinez ◽

Alejandra Jimenez Madrid ◽

Loic Deblais ◽

Christopher Taylor ◽

...

Keyword(s):

Root Rot ◽

Black Dot ◽

Tomato Production ◽

Soil Disinfestation ◽

Soilborne Disease ◽

Disease Complex ◽

Anaerobic Soil Disinfestation ◽

Corky Root ◽

High Tunnels ◽

Corky Root Rot

Tomato production in Ohio protected culture systems is hindered by a soilborne disease complex consisting of corky root rot (Pyrenochaeta lycopersici), black dot root rot (Colletotrichum coccodes), Verticillium wilt (Verticillium dahliae), and root-knot (Meloidogyne hapla and M. incognita). In a survey of 71 high tunnels, C. coccodes was detected in 90% of high tunnels, while P. lycopersici (46%), V. dahliae (48%) and Meloidogyne spp. (45%) were found in nearly half of high tunnels. Anaerobic soil disinfestation (ASD) with wheat bran (20.2 Mg/ha) plus molasses (10.1 Mg/ha) and grafting onto ‘Maxifort’ or ‘Estamino’ rootstocks were evaluated in high tunnels on five farms. In post-ASD bioassays using trial soils, root and taproot rot severity were significantly reduced following ASD, and root-knot galling was also reduced by ASD. Soilborne pathogenic fungi were isolated less frequently from bioassay plants grown in ASD-treated soils than control soils. Similar results were observed in tomato plants grown in high tunnels. Root rot was significantly reduced by ASD in nearly all trials. Corky root rot severity was highest in non-grafted plants grown in non-treated soils, while the lowest levels of corky root rot were observed in Maxifort-grafted plants. Black dot root rot severity was higher or equivalent in grafted plants compared to non-grafted plants. Root-knot severity was lower in plants grown in ASD-treated soils in high tunnels compared to plants grown in control soils, but grafting did not significantly decrease root-knot severity. However, soil treatment did not significantly impact yield, and grafting led to inconsistent impacts on yield.

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Improved nutrient status and Fusarium root rot mitigation with an inoculant of two biocontrol fungi in the common bean (Phaseolus vulgaris L.)

Rhizosphere ◽

10.1016/j.rhisph.2019.100172 ◽

2019 ◽

Vol 12 ◽

pp. 100172 ◽

Cited By ~ 2

Author(s):

Pierre Eke ◽

Louise Nana Wakam ◽

Patrick Valère Tsouh Fokou ◽

Therese Virginie Ekounda ◽

Kuleshwar Prasard Sahu ◽

...

Keyword(s):

Phaseolus Vulgaris ◽

Common Bean ◽

Root Rot ◽

Nutrient Status ◽

Phaseolus Vulgaris L ◽

Fusarium Root Rot ◽

The Common ◽

Biocontrol Fungi

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Carbon Source and Soil Origin Shape Soil Microbiomes and Tomato Soilborne Pathogen Populations During Anaerobic Soil Disinfestation

Phytobiomes Journal ◽

10.1094/pbiomes-02-18-0007-r ◽

2018 ◽

Vol 2 (3) ◽

pp. 138-150 ◽

Cited By ~ 12

Author(s):

Anna L. Testen ◽

Sally A. Miller

Keyword(s):

Carbon Source ◽

Wheat Bran ◽

Root Rot ◽

Bacterial Communities ◽

Soilborne Diseases ◽

Soil Disinfestation ◽

Anaerobic Soil Disinfestation ◽

Soil Bacterial Communities ◽

Soil Origin ◽

Soil Bacterial

Soilborne disease complexes are an emerging constraint in protected culture tomato production systems in the Midwestern United States. Diseases in these complexes include Verticillium wilt (Verticillium dahliae), black dot root rot (Colletotrichum coccodes), corky root rot (Pyrenochaeta lycopersici), and root knot (Meloidogyne spp.). Anaerobic soil disinfestation (ASD) may be a viable, environmentally benign strategy for managing these complexes. Soils from two farms in Ohio were used to determine the impacts of ASD, using wheat bran, molasses, or ethanol as carbon sources, on soilborne diseases and soil bacterial communities. ASD with wheat bran or ethanol amendments led to significantly reduced tomato root rot severity, while nematode galling damage was significantly reduced following ASD with any carbon source compared with nontreated controls. When ethanol was used as a carbon source in ASD, the colonization of tomato roots by P. lycopersici and C. coccodes was observed less frequently than in control roots. A high throughput sequencing approach was used to characterize soil bacterial communities following ASD. Carbon source and soil origin influenced the composition of bacterial communities in soils treated with ASD. Bacterial community diversity decreased following ASD with wheat bran in all soils tested and following ASD with ethanol in soils from one farm. The abundance of bacteria in the phylum Firmicutes generally increased significantly following ASD, while the abundance of those in the phyla Acidobacteria, Actinobacteria, Chloroflexi, and Plantomycetes generally decreased following ASD. These findings provide insight into the impacts of ASD on microbial communities and soilborne diseases and will be used to optimize ASD as a tool for Midwestern vegetable growers.

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Identification of Quantitative Trait Loci Conditioning Resistance to Fusarium Root Rot in Common Bean

Crop Science ◽

10.2135/cropsci2005.0028 ◽

2005 ◽

Vol 45 (5) ◽

pp. 1881-1890 ◽

Cited By ~ 44

Author(s):

Belinda Román-Avilés ◽

James D. Kelly

Keyword(s):

Quantitative Trait Loci ◽

Common Bean ◽

Quantitative Trait ◽

Root Rot ◽

Fusarium Root Rot ◽

Trait Loci

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Mycorrhiza consortia suppress the fusarium root rot ( Fusarium solani f. sp. Phaseoli ) in common bean ( Phaseolus vulgaris L.)

Biological Control ◽

10.1016/j.biocontrol.2016.10.001 ◽

2016 ◽

Vol 103 ◽

pp. 240-250 ◽

Cited By ~ 18

Author(s):

Pierre Eke ◽

Gael Chatue Chatue ◽

Louise Nana Wakam ◽

Rufin Marie Toghueo Kouipou ◽

Patrick Valère Tsouh Fokou ◽

...

Keyword(s):

Phaseolus Vulgaris ◽

Common Bean ◽

Fusarium Solani ◽

Root Rot ◽

Phaseolus Vulgaris L ◽

Fusarium Root Rot

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Synergy of Anaerobic Soil Disinfestation and Trichoderma spp. in Rhizoctonia Root Rot Suppression

Frontiers in Sustainable Food Systems ◽

10.3389/fsufs.2021.645736 ◽

2021 ◽

Vol 5 ◽

Author(s):

Ram B. Khadka ◽

Sally A. Miller

Keyword(s):

Carbon Source ◽

Rhizoctonia Solani ◽

Wheat Bran ◽

Root Rot ◽

Carbon Sources ◽

Chicken Manure ◽

Treated Soil ◽

Soil Disinfestation ◽

Anaerobic Soil Disinfestation ◽

Rhizoctonia Root Rot

Potential synergy between anaerobic soil disinfestation (ASD) and Trichoderma spp. in suppression of Rhizoctonia root rot in radish was evaluated. A split-plot design with three replications was used; main plots were Trichoderma harzianum T22, Trichoderma asperellum NT25 and a non-Trichoderma control. Subplots were ASD carbon sources wheat bran, molasses, chicken manure, and mustard greens and two non-amended controls: anaerobic (covered and flooded) and aerobic (not covered or flooded). Carbon sources and Rhizoctonia solani inoculant were mixed with soil, placed in pots, and flooded, followed by drenching Trichoderma spore suspensions and sealing the pots in zip-lock bags. After 3 weeks, bags were removed, soil was aired for 1 week and radish “SSR-RR-27” was seeded. Rhizoctonia root rot severity and incidence were lowest in radish plants grown in ASD-treated soil amended with wheat bran, molasses, or mustard greens across all Trichoderma treatments. Disease severity was lower in radish plants treated with NT25 than with T22 or the non-Trichoderma control across all ASD treatments, and in radish grown in ASD-treated soil amended with wheat bran plus NT25 compared to ASD-wheat bran or NT25 alone. Rhizoctonia solani populations were significantly reduced by ASD treatment regardless of carbon source, while Trichoderma populations were not affected by ASD treatment with the exception of ASD-mustard greens. The interactions of either Trichoderma isolate and ASD with most carbon sources were additive, while T22 with ASD-molasses and NT25 with ASD–wheat bran interactions were synergistic in reducing disease severity. One interaction, T22 with ASD-chicken manure was antagonistic. Enhancement of ASD efficacy in suppressing soilborne diseases such as Rhizoctonia root rot by additional soil amendment with Trichoderma spp. during the process appears to be dependent on both Trichoderma isolate and ASD carbon source.

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