Chloropicrin (Pic) and biofumigation are both considered effective chemical and non-chemical alternatives to methyl bromide, respectively, for controlling crop-limiting soil-borne pests and diseases. ...In this study, we evaluated the effects of Pic alone and ‘chloropicrin alternated with biofumigation’ (CAB) on the soil's physico-chemical properties and strawberry yield, as well as their effects on soil bacterial and fungal communities. The contents of NO3−-N, available phosphorus and potassium, and electrical conductivity were all significantly increased when CAB was used. In addition, CAB also significantly increased the strawberry marketable yield. High-throughput gene sequencing showed the species abundance of some soil bacteria and fungi was significantly increased such as the phyla Proteobacteria, Bacteroidetes, Actinobacteria and Ascomycota when CAB was used. However, CAB decreased the relative abundance of the phyla Firmicutes, Chloroflexi, Gemmatimonadete and Zygomycota. These results indicated that CAB could improve the physico-chemical properties of soil for strawberry production, increase the genetic diversity of microbes in the soil and enhance marketable fruit yield.
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•Our study introduced a new method of soil fumigation to reduce the use of chemical fumigants.•Chloropicrin alternated with biofumigation (CAB) can improve nutrient elements in chloropicrin fumigation plots.•Chloropicrin alternated with biofumigation (CAB) also increased strawberry yields•Chloropicrin alternated with biofumigation (CAB) significantly impacts soil bacterial and fungal community diversity.
•The VOCs could be employed as gaseous treatments in a process defined ‘biofumigation’.•These biobased products are an eco-chemical approach in postharvest disease control.•The VOCs can be applied as ...MAP, incorporated into edible films or in active packaging.•The VOCs play a key role against postharvest pathogens.
Significant postharvest losses occur during the supply chain of fresh produce. Postharvest decay is one of the main factors that determines losses and compromises the quality of fruit and vegetables. Traditionally postharvest decay control is achieved using chemical fungicides; however, the important concerns relating to environmental and human health require the development of novel methods for the control of postharvest decay. Furthermore, the consumer demand and the purchasing power are higher for fresh produce that are free from pesticide application. This review highlights the research literature based information on the application of microbial and plant volatile organic compounds (VOCs) to control postharvest decay, their practical applications in postharvest systems and the future perspectives. The volatile nature of VOCs could be potentially employed with success as gaseous treatments in a process defined ‘biofumigation’. Plant-produced volatiles including among others, aldehydes such as acetaldehyde, 2-E-hexenal and benzaldehyde, alcohols such as ethanol and acetic acid, essential oils (EOs) and isothiocyanates (ITCs) and microbial volatile organic compounds have been recognised as potential substances in preventing pathogenic infections in many horticultural commodities. However, some issues have to be well elucidated in order to admit these substances in a large-scale application to improve the competitiveness of the fresh produce at the quality stringent EU, USA, and the Japanese markets. The main concern are related to the registration process, but also VOCs degradation and residues in fruit, formulation and organoleptic impact, are aspects that have to be thoroughly considered prior to commercialisation of the selected VOC. Furthermore, VOCs could have an effective role for an eco-chemical approach in postharvest disease control since these biobased products, if compared to conventional ones, can offer clear environmental benefits due to their renewability, biodegradability and hypotoxicity.
Brassica plants play an important role in common agricultural practices, such as livestock feed or biofumigation, due to the bioactivity of the natural degradation products of glucosinolate ...metabolites. Therefore, the ability to survey comprehensive glucosinolate profiles for individual brassicas is essential for informing proper species selection for the intended application. Current methods for glucosinolate identification and quantification involve complex or unconventional procedures, and proper reference materials are not readily available. Therefore, researchers with limited resources that require glucosinolate profiles are at an extreme disadvantage. In this work, a simple and accurate HPLC-MS method was developed and validated to build preliminary glucosinolate profiles for three agriculturally relevant forage brassica varieties turnip (B. rapa L.), canola (B. napus L.), and rapeseed (B. napus L.). The average glucosinolate content across three herbage collection dates for canola, rapeseed and turnip were 2.9 ± 0.9 mg g−1, 6.4 ± 1.3 mg g−1, and 14 ± 3.4 mg g−1, respectively. GLS concentrations are reported in milligrams of glucosinolate, calculated as sinigrin equivalents, per gram of dry plant material. This semi-quantitative approach for reporting total GLS content in brassicas is accurate within 15%. Several minor individual glucosinolates were identified that have not been previously reported in canola, rapeseed and turnip species, including glucotropaeolin and 4-hydroxyglucobrassicin (canola), glucoraphanin and glucoberteroin (rapeseed), and glucosinalbin and glucobarbarin (turnip). This non-targeted screen of several forage brassica varieties demonstrates the inherent variation in both the individual glucosinolate content and the total glucosinolate profile among brassicas, and highlights the importance of such glucosinolate characterization in agricultural practices. Additionally, the method developed in this study can be used as a tool for researchers with limited resources to build accurate glucosinolate profiles of brassica plants.
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•Glucosinolate determination by mass spectrometry.•Identification of glucosinolates in brassicas.•Simple and efficient method for building a glucosinolate profile.
One of the main phytosanitary problems inthe production of tomato(tomate or jitomatein spanish)(Solanum lycopersiconMill.),where soil is used as a growing medium,is Fusarium spp., chemical control is ...the method frequently used for its management; with important economic and environmental impacts. The objectives of this study were: to evaluate cabbage as a rotation crop and the incorporation of residues into the soil in the incidence of permanent wilting on tomato plants and the incidence ofFusariumspp., in the soil and evaluate thesuppression of Fusariumspp., by applying by-products of cabbage leaves and stems. The study was carried out in two stages: in the first the evolution of Fusariumspp.,was documentedin a commercial tomato cultivation, established under anti-aphid mesh conditions and cabbageas arotation crop, during the period 2012 to 2019. In the second stage, an aqueous extract and a dehydrated powder, obtained from residual cabbage leaves and stems, were evaluated. The results show that cabbage used as a rotation cropand the incorporation into the soil of residual leaves and stems reduced the incidence of permanent wilting on tomato cultivation and effectively suppressed Fusarium spp. Aswell,the dehydrated powder obtained from these residues showed a similar effect on the control of Fusariumspp., to thatobtained in treatments with sodium methyldithiocarbamate.
Uno de los principales problemas fitosanitarios en la producción de tomate o jitomate (Solanum lycopersiconMill.) donde se utiliza el suelo como medio de cultivo es Fusarium spp., el control químico es el método frecuentemente utilizado para su manejo; con impactos económicos y ambientales importantes. Los objetivos del presente estudio fueron: evaluar el repollo como cultivo de rotación y la incorporación de los residuos al suelo sobre la incidencia de la marchitez permanente en plantas de tomate e incidencia de Fusariumspp., en el suelo y evaluar la supresión de Fusariumspp., mediante la aplicación de subproductos de hojas y tallos de repollo. El trabajo se realizó en dos etapas: en la primera se documentó la evolución de Fusarium spp., en un cultivo comercial de tomate, establecido bajo condiciones de malla antiáfidos y repollo como cultivo de rotación, durante el periodo de 2012 a 2019. En la segunda etapa, se evaluó un extracto acuoso y un polvo deshidratado, obtenidos de hojas y tallos residuales de repollo. Los resultados muestran que el repollo utilizado como cultivo de rotación y la incorporación al suelo de las hojas y tallos residuales, redujeron la incidencia de marchitez permanente en el cultivo de tomate y suprimieron eficazmente Fusarium spp. Asimismo, el polvo deshidratado obtenido de estos residuos mostró un efecto similar sobre el control de Fusarium spp.,al obtenido en los tratamientos con metilditiocarbamato de sodio.
Understanding the components that shape the rhizosphere community is vital for sustainable disease management. This study evaluated an integrated Verticillium wilt management in eggplant and its ...influence on the soil microbiome. Six treatments; Self-rooted (control; CLA) and sole grafted (CLB) eggplants, Brassica + Self-rooted plant (BrA), and Brassica + Grafted plants (BrB), with Biochar (10 t/ha) + Brassica + Self-rooted plant (BBrA) and Biochar (10 t/ha) + Brassica + Grafted Plant (BBrB) were used. Soil microbiome was characterized using high-throughput sequencing. The grafted treatments significantly reduced the Verticillium abundance, disease index and improved the yield of eggplant compared with CLA (18.13 t/ha), with BBrB (41.54 t/ha) as the best treatment. Results showed that treatments CLB, BrB, and BBrB stimulated more beneficial microbes, especially Arthrobacter, Bacillus, and Sphingomonas for bacteria; and Mortierella, Tausonia, and Chaetomium for fungi. Treatment BBrB was biomarked by phylum Chloroflexi (o_SBR1031), Acidobacteria, Planctomycetes, and Patescibacteria, but only Chloroflexi (o_SBR1031) was found in BrB, and none of them in CLB and treatment BBrB also contained more biomarkers than other treatments. Similarly, the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis revealed that treatment BBrB contained more genes (17.5%) regulating disease resistance followed by BrB (17.3%) and CLB (16.6%) treatments. In conclusion, grafting with Brassica (biofumigation) under a biochar regime could reduce eggplant Verticillium wilt. This study expands knowledge on how soil microbiota can be enhanced using integrated disease management practices to exploit sustainable food production.
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•Suppression of Verticillium wilt disease with different control methods was studied.•The combination of grafting, biochar, and brassica manuring significantly increased eggplant yield.•The genera Bacillus, Sphingomonas, and Arthrobacter increased in the rhizosphere with grafting.•Integrated control methods may be required for the long-term management of Verticillium wilt disease.
•Mixture of volatiles produced by the antagonist S. cerevisiae inhibits P. citricarpa.•Volatiles reduce mycelial growth, germination and appressorium formation of conidia.•Production of ...3-methyl-1-butanol is the main responsible for the biocontrol activity.•Biofumigation of fruits with S. cerevisiae reduces the citrus black spot at postharvest.
Volatile organic compounds (VOCs) from microbial origin are relevant in biological interactions and are considered promising environmentally safer fumigant agents to control postharvest diseases of fruits. The antagonist yeast Saccharomyces cerevisiae produces VOCs able to inhibit the development of plant pathogens, including the filamentous fungus Phyllosticta citricarpa, causal agent of citrus black spot. Thus, it was evaluated the effectiveness of VOCs produced by S. cerevisiae to control P. citricarpa in orange fruits stored in sealed glass containers. The exposure of P. citricarpa growing on potato-dextrose-agar to the synthetic mixture of VOCs, originally identified from S. cerevisiae, affected negatively the phytopathogen. Individually, 3-methyl-1-butanol and 2-methyl-1-butanol were the most effective VOCs inhibiting completely the mycelial growth and the germination and appressorium formation by conidia. Seven-day fumigation of orange fruits carrying quiescent infections of P. citricarpa, employing the VOC-producing S. cerevisiae or 3-methyl-1-butanol at 0.33μlml−1 of air space, controlled the development of new lesions close to 90%, even after removing the fruits from the VOC influence. Therefore, the biological fumigation of citrus fruits with S. cerevisiae or the use of formulations based on their VOCs are promising ecofriendly approaches to control citrus black spot during storage and shipment.
The use of green manure and biofumigant crops within cropping rotations is a common practice for increasing soil fertility, organic carbon levels, improving soil aggregation and preventing erosion. ...These practices aim to increase the resilience of agricultural soils to degradation and protect important ecosystem services. However, knowledge of how soil microbial communities respond to biofumigation and green manuring at fine time scales is lacking, and this information is required to determine when organic amendments produce their maximum effect and how long their effects last.
This study compared how a winter-grown ryegrass green manure (Lolium multiflorum, var. Tetila) and brassica biofumigant (Brassica juncea, var. Caliente 199) affected the bacterial, fungal and non-fungal eukaryote communities of an intensively cropped temperate vegetable production soil. The aim was to determine the timing, magnitude and duration of ryegrass green manuring and brassica biofumigation's effects on the microbial community dynamics of the bulk soil. We analysed the soil microbial communities with high throughput amplicon sequencing of soil DNA extracts at key times within one growing season, focussing on the period around incorporation, to determine how the communities changed in response to the treatments.
Ryegrass and biofumigant green manure crops both had significant effects on the soil microbial ecosystem, and the fungal and non-fungal eukaryote communities were more responsive than the bacteria. Community change in the biofumigant and ryegrass treated plots was greatest in the weeks immediately after incorporation and slowly receded with time. However, the fungal and non-fungal eukaryote communities of all treatments remained significantly different to each other at the end of the experiment 35 weeks post-incorporation. We also found that soil pH was variable across the site and strongly related to differences in bacterial, fungal and eukaryote community structure.
•Green manure incorporation affects soil microbial communities within days.•Brassica biofumigant affected soil microbiome more than a standard green manure.•Soil microbiome changes persisted for 8 months post green manuring/biofumigation.•Soil fungi and eukaryote communities were more responsive than bacteria.
Brassica crop rotations have been associated with the reduction of pathogens, due to both the production of volatile sulfur compounds and changes in soil microbial community composition. In this ...research Brassica carinata, as break crop green manure, was evaluated for the control of common root rot and Fusarium foot rot of durum wheat in a complete randomized experimental scheme. Field trials were performed on seven farms, in some of the most representative areas of cereal production in Sicily, from 2011 to 2013. A total eradication of Bipolaris sorokiniana and Microdochium nivale populations following the B. carinata break crop, as compared to wheat monoculture, was found in all experimental fields. Fusarium culmorum population reduction ranged between 90% and 66%, with an average of 82% considering all field trials data. Symptoms or signs of common root rot were absent on wheat plants grown after the B. carinata break crop but were detectable on the wheat monoculture. Both incidence and severity of Fusarium foot rot were also reduced, by an average of 40.6% and 56.3%, respectively, following the B. carinata break crop in six of the seven field trials. After B. carinata break crop, wheat plant growth showed significant increases in height and weight, with an average increase of 48.3% and 49.0% respectively. Durum wheat grain yield was also significantly greater following the Brassica green manure, with increases ranging from 9.5% to 62.2%, as compared to wheat monoculture. B. carinata break crop green manure was also characterized by interesting results in terms of disease management in comparison to controls. These results suggest that the use of Brassicas such as B. carinata, as a break crop green manure, may potentially provide significant reduction of pathogens and disease development as well as improvement in grain yield of the succeeding crop.
•Effects of Brassica carinata for management of root and foot rot of wheat were evaluated.•Results show improvements in terms of pathogen and disease inhibition.•B. carinata increased grain yield of the succeeding crop.
Nurseries producing apple and rose rootstock plants, apple orchards as well as rose production often experience replanting problems after several cultivations at the same site when a chemical soil ...disinfectant is not applied. The etiology of apple and rose replanting problems is most likely caused by soil-borne pathogen complex, defined as "replant disease (RD)". Symptoms typical of RD are reduced shoot and root growth, a smaller leaf area, a significant decrease in plant biomass, yield and fruit quality and a shorter life span. In our previous study, we showed that RD symptoms were reduced when apple rootstock M106 were grown in RD soils treated either with the soil fumigant Basamid or after biofumigation by incorporating
or
or by growing
under field conditions compared to untreated control soil. The present study aimed at identifying potential bacterial and fungal taxa that were affected by different soil treatments and linking bacterial and fungal responders to plant performance. Miseq® Illumina® sequencing of 16S rRNA gene fragments (bacteria) and ITS regions (fungi) amplified from total community DNA extracted from soil samples taken 4 weeks after treatments were performed. Soil properties and culture history of the two RD sites greatly influenced soil microbiomes. Several bacterial genera were identified that significantly increased in treated soils such as
(
, both sites),
(Basamid, both sites),
(Basamid and
, site A) and
(
, site K and
, site A) that were also significantly and positively correlated with growth of apple M106 plants. Only few fungal genera, such as
and
, were significantly promoted in soils treated with
and
(both sites). The least pronounced changes were recorded for bacterial as well as fungal communities in the RD soils planted with
. The detection of bacterial and fungal genera that were significantly increased in relative abundance in response to the treatments and that were positively correlated with plant growth suggests that management of the soil microbial community could contribute to overcome the apple RD encountered at affected sites.
Biofumigation is used to control soil-borne plant diseases, and it has paramount importance to reduce the cost of chemical fumigants. Information about the field control efficacies and impacts of ...Brassica-based biofumigation (BBF) on soil bacterial and fungal microbiota is scattered in the literature. Therefore, this review summarizes and discusses the nature and the underlying causes of soil bacterial and fungal community dynamics in response to BBF. In addition, the major factors influencing the interaction between a biofumigant and soil microbiota are discussed. The pros and cons of BBF to soil microbiota and the subsequent impacts on sustainable farming practices are also highlighted.
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