scholarly journals Rotation and Cover Crop Effects on Soilborne Potato Diseases, Tuber Yield, and Soil Microbial Communities

Plant Disease ◽  
2010 ◽  
Vol 94 (12) ◽  
pp. 1491-1502 ◽  
Author(s):  
Robert P. Larkin ◽  
Timothy S. Griffin ◽  
C. Wayne Honeycutt
Keyword(s):  
Microbial Communities ◽  
Verticillium Wilt ◽  
Cover Crop ◽  
Common Scab ◽  
Tuber Yield ◽  
Soil Microbial Communities ◽  
Black Scurf ◽  
Winter Rye ◽  
Bacterial Populations ◽  
Soil Microbial

Seven different 2-year rotations, consisting of barley/clover, canola, green bean, millet/rapeseed, soybean, sweet corn, and potato, all followed by potato, were assessed over 10 years (1997–2006) in a long-term cropping system trial for their effects on the development of soilborne potato diseases, tuber yield, and soil microbial communities. These same rotations were also assessed with and without the addition of a fall cover crop of no-tilled winter rye (except for barley/clover, for which underseeded ryegrass was substituted for clover) over a 4-year period. Canola and rapeseed rotations consistently reduced the severity of Rhizoctonia canker, black scurf, and common scab (18 to 38% reduction), and canola rotations resulted in higher tuber yields than continuous potato or barley/clover (6.8 to 8.2% higher). Addition of the winter rye cover crop further reduced black scurf and common scab (average 12.5 and 7.2% reduction, respectively) across all rotations. The combined effect of a canola or rapeseed rotation and winter rye cover crop reduced disease severity by 35 to 41% for black scurf and 20 to 33% for common scab relative to continuous potato with no cover crop. Verticillium wilt became a prominent disease problem only after four full rotation cycles, with high disease levels in all plots; however, incidence was lowest in barley rotations. Barley/clover and rapeseed rotations resulted in the highest soil bacterial populations and microbial activity, and all rotations had distinct effects on soil microbial community characteristics. Addition of a cover crop also resulted in increases in bacterial populations and microbial activity and had significant effects on soil microbial characteristics, in addition to slightly improving tuber yield (4% increase). Thus, in addition to positive effects in reducing erosion and improving soil quality, effective crop rotations in conjunction with planting cover crops can provide improved control of soilborne diseases. However, this study also demonstrated limitations with 2-year rotations in general, because all rotations resulted in increasing levels of common scab and Verticillium wilt over time.

scholarly journals Effects of Crop Rotation and Biocontrol Amendments on Rhizoctonia Disease of Potato and Soil Microbial Communities

Agriculture ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 128 ◽  
Author(s):  
Robert P. Larkin ◽  
Marin T. Brewer
Keyword(s):  
Microbial Communities ◽  
Tuber Yield ◽  
Soil Microbial Communities ◽  
Stem Canker ◽  
Field Trials ◽  
Interactive Effects ◽  
Soil Microbial ◽  
Complex Interactions ◽  
Rhizoctonia Disease ◽  
Rotation Crops

Rotation crops and biocontrol amendments were investigated for suppression of Rhizoctonia solani on potato (Solanum tuberosum) and their interactive effects on soil microbial communities. Greenhouse trials were conducted to evaluate selected rotation crops, including barley, common and “Lemtal” ryegrass, clover, potato, and combinations of barley with ryegrass or clover, for their effects on populations of R. solani and Rhizoctonia disease. Potato and clover preceding potato resulted in higher disease severity than most other rotations, whereas ryegrass reduced stem canker severity. In addition, all ryegrass treatments resulted in substantially higher populations of R. zeae. Field trials evaluating selected biocontrol treatments in combination with different rotations were conducted at two locations in Maine. Potatoes were treated with the biocontrol organisms Laetisaria arvalis, Trichoderma virens, or Bacillus subtilis and planted following rotation crops of barley and ryegrass, barley and clover, or potato. The barley/ryegrass rotation significantly reduced incidence and severity of stem canker and increased tuber yield at one location. Efficacy of the biocontrol treatments varied by rotation and location, with L. arvalis and T. virens reducing black scurf in some rotations and increasing some aspects of tuber yield at one location. Soil microbial community characteristics differed among rotation crops and biocontrol treatments. Significant crop by biocontrol interactions were observed demonstrating the complex interactions among rotation crops, biocontrol treatments, and soil microbial communities, as well as indicating that biocontrol can be enhanced within beneficial rotations.

scholarly journals Management and Soil Conditions Influence Common Scab Severity on Potato Tubers Via Indirect Effects on Soil Microbial Communities

2020 ◽  
Vol 110 (5) ◽  
pp. 1049-1055
Author(s):  
Emily W. Lankau ◽  
Dianne Xue ◽  
Rachel Christensen ◽  
Amanda J. Gevens ◽  
Richard A. Lankau
Keyword(s):  
Microbial Communities ◽  
Indirect Effects ◽  
Common Scab ◽  
Soil Microbial Communities ◽  
Farm Management ◽  
Equation Modeling ◽  
Soil Conditions ◽  
Potato Market ◽  
Soil Microbial ◽  
Soil Bacterial

Common scab, caused by Streptomyces scabies and related species, is a potato tuber blemish disease that causes reductions in marketable yield worldwide. Evidence of suppression of common scab by indigenous soil microbial populations has been found in several studies. However, we lack a comprehensive understanding of how common scab severity relates functionally to potato varieties, farming systems, soil physical and chemical properties, and soil microbial communities. These factors may affect disease directly or indirectly by affecting one of the other variables. We performed a survey of 30 sampling locations across 12 fields in Wisconsin and used structural equation modeling to disentangle the direct effects of potato market classes, farm management (conventional versus organic), and soil physiochemical properties on common scab severity from their indirect effects mediated through soil bacterial and fungal communities. We found that, although potato market classes affected disease severity directly, the effects of farm management and soil physiochemistry were best explained as indirect, mediated by their impacts on soil bacterial communities. This suggests that evaluating the consequences of specific management practices for soil microbial communities may be useful for understanding disease pressure across fields.

scholarly journals Cover crop-driven shifts in soil microbial communities could modulate tomato early crop growth via plant-soil feedbacks

2021 ◽  
Author(s):  
Micaela Tosi ◽  
John Drummelsmith ◽  
Dasiel Obregón ◽  
Inderjot Chahal ◽  
Laura L. Van Eerd ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Cover Crops ◽  
Cover Crop ◽  
Crop Residues ◽  
Management Strategies ◽  
Soil Microbial Communities ◽  
Crop Productivity ◽  
Residue Management ◽  
Soil Microbial ◽  
Plant Soil

Abstract Sustainable agricultural practices such as crop diversification, cover crops and residue retention are increasingly applied to counteract detrimental effects of agriculture on natural resources. Since part of their effects occur via changes soil microbial communities, it is critical to understand how these respond to different practices. Our study analyzed five cover crop (cc) treatments (oat, rye, radish, rye-radish mixture and no-cc control) and two crop residue management strategies (retention/R+ or removal/R-) in an 8-year diverse horticultural crop rotation trial from ON, Canada. Cc effects were small but stronger than those of residue management. Radish-based cover crops tended to be the most beneficial for both microbial abundance and richness, yet detrimental for fungal evenness. Cc species, in particular radish, also shaped fungal and, to a lesser extent, prokaryotic community composition. Crop residues modulated cc effects on bacterial abundance and fungal evenness (i.e., more sensitive in R- than R+), as well as microbial taxa. Several microbial structure features, some affected by cc, were correlated with early tomato growth in the following spring (e.g., composition, taxa within Actinobacteria, Firmicutes and Ascomycota). Our study suggests that, whereas mid-term cc effects were small, they need to be better understood as they could be influencing crop productivity via plant-soil feedbacks.

scholarly journals Management of Verticillium Wilt of Potato with Disease-Suppressive Green Manures and as Affected by Previous Cropping History

Plant Disease ◽  
2011 ◽  
Vol 95 (5) ◽  
pp. 568-576 ◽  
Author(s):  
Robert P. Larkin ◽  
C. Wayne Honeycutt ◽  
O. Modesto Olanya
Keyword(s):  
Verticillium Wilt ◽  
Tuber Yield ◽  
Potato Crop ◽  
Soil Microbial Communities ◽  
Soil Microbiology ◽  
Disease Suppression ◽  
Green Manures ◽  
Soilborne Diseases ◽  
Soil Microbial ◽  
Disease Reduction

The ability of disease-suppressive rotation crops to reduce potato disease problems and increase crop productivity in a field with prior severe Verticillium wilt, as well as the potential influence of previous cropping history on disease suppression, was evaluated over three field seasons in Maine. Disease-suppressive rotations consisted of: (i) a high-glucosinolate mustard blend (‘Caliente 119’) as a mixture of white mustard (Sinapis alba) and oriental mustard (Brassica juncea) with known biofumigation potential and (ii) a sorghum-sudangrass hybrid. Each were grown as single-season green manures followed by a subsequent potato crop. These rotations were compared with a standard barley rotation and a barley rotation followed by chemical fumigation with metam sodium as controls. Both green manure rotations significantly reduced (average reductions of 25 and 18%, respectively) Verticillium wilt in the subsequent potato crop compared with the standard barley control but were not as effective as chemical fumigation (35% reduction). The mustard blend also reduced other soilborne diseases (black scurf and common scab) better than all other rotations. Mustard blend and chemical fumigation treatments increased tuber yield relative to the barley control by 12 and 18%, respectively. However, by the second rotation cycle, disease levels were high in all rotations, and only chemical fumigation resulted in substantial disease reduction (35%). Rotations also had significant effects on soil microbiology, including soil bacterial and fungal populations and microbial community characteristics based on fatty acid profiles. However, only chemical fumigation significantly reduced soil populations of Verticillium spp. and increased general soil microbial activity. Previous cropping history did not significantly affect disease reduction, tuber yield, or soil microbial communities. This research indicates the potential for using disease-suppressive rotations for managing Verticillium wilt and other soilborne diseases but also indicates that multiple years of disease-suppressive crops may be needed to substantially reduce disease in heavily infested fields.

scholarly journals Soil Microbial Communities in Corn Fields Treated with Atoxigenic Aspergillus flavus

Soil Systems ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 35 ◽  
Author(s):  
Krishna B. Bhandari ◽  
Scott D. Longing ◽  
Charles P. West
Keyword(s):  
Microbial Communities ◽  
Aspergillus Flavus ◽  
Methyl Esters ◽  
Soil Microbial Communities ◽  
Aflatoxin Contamination ◽  
Bacterial Populations ◽  
Soil Microbial Community Structure ◽  
Soil Microbial ◽  
Corn Fields ◽  
And Control

Aspergillus flavus refers to a diverse group of saprophytic soil fungi that includes strains producing aflatoxins (toxigenic strains) in the kernels of corn (Zea mays L.) and other crops, causing pre-harvest and post-harvest aflatoxin contamination. Some A. flavus strains are atoxigenic, and the introduction of such strains into the crop environment helps reduce toxigenic aflatoxin contamination. Corn growers in Texas have used the product FourSure™, which contains four atoxigenic strains of A. flavus; however, effects on soil microbial communities associated with these applications are unknown. We compared soil fungal and bacterial communities in corn fields treated with FourSure™ to nearby untreated (control) corn fields in Texas during the summer of 2019. Analysis of soil microbial community structure showed that total fatty acid methyl esters (FAMEs), fungal, and bacterial populations were not significantly different (p = 0.31) between the FourSure™-treated and control fields, yet corn fields located in the northern counties had more (p < 0.05) Gram—bacteria, actinobacteria, and total bacteria than fields in the southernmost county. The Gram—bacteria and actinobacteria were positively correlated (p = 0.04; r = 0.48 and 0.49, respectively) with soil water content. Similar fungal and bacterial abundances between FourSure™-treated and control fields indicated that atoxigenic A. flavus had no negative effects on soil microbial communities.

scholarly journals Breaking continuous potato cropping with legumes improves soil microbial communities, enzyme activities and tuber yield

PLoS ONE ◽  
2017 ◽  
Vol 12 (5) ◽  
pp. e0175934 ◽  
Author(s):  
Shuhao Qin ◽  
Stephen Yeboah ◽  
Li Cao ◽  
Junlian Zhang ◽  
Shangli Shi ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Enzyme Activities ◽  
Tuber Yield ◽  
Soil Microbial Communities ◽  
Soil Microbial

Soil microbial communities under cacao agroforestry and cover crop systems in Peru

2017 ◽  
Vol 120 ◽  
pp. 273-280 ◽  
Author(s):  
Jeffrey S. Buyer ◽  
Virupax C. Baligar ◽  
Zhenli He ◽  
Enrique Arévalo-Gardini
Keyword(s):  
Microbial Communities ◽  
Cover Crop ◽  
Soil Microbial Communities ◽  
Soil Microbial

scholarly journals SOIL MICROBIAL COMMUNITIES AS AFFECTED BY A COMMERCIAL ORGANIC FERTILIZER AND SUNN HEMP AS A COVER CROP IN ORGANIC SWEET PEPPER PRODUCTION IN PUERTO RICO

1969 ◽  
Vol 99 (1) ◽  
pp. 53-57
Author(s):  
Ana Negrete ◽  
Elide Valencia-Chin ◽  
Verónica Acosta-Martínez
Keyword(s):  
Puerto Rico ◽  
Microbial Communities ◽  
Cover Crop ◽  
Organic Fertilizer ◽  
Soil Microbial Communities ◽  
Sweet Pepper ◽  
Soil Microbial ◽  
Sunn Hemp

SOIL MICROBIAL COMMUNITIES AS AFFECTED BY A COMMERCIAL ORGANIC FERTILIZER AND SUNN HEMP AS A COVER CROP IN ORGANIC SWEET PEPPER PRODUCTION IN PUERTO RICO

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