Using combinations of biocontrol agents to control Botrytis cinerea on strawberry leaves under fluctuating temperatures

Experiments were conducted with Botrytis cinerea on strawberry leaves to investigate where combinations of commercially available biological control agents (BCAs) might control B. cinerea more effectively than individual BCAs. Specifically, we studied the persistence of biocontrol activities, spread of BCAs among leaves, and biocontrol efficacy in relation to application regimes: mixed versus single BCA, pre-versus post-inoculation application, and sequential versus simultaneous application. Three BCA products (Sentinel, Serenade and Trianum) were used for this study. Overall, Serenade did not significantly reduce sporulation of B. cinerea on strawberry leaf discs whereas Sentinel and Trianum gave a similar and significant biocontrol efficacy. Biocontrol efficacy remained almost unchanged 10 days after application at 20/20°C (day/night) or 24/16°C temperature regimes. In contrast, reduced biocontrol efficacy at 26/14°C suggests BCA survival was reduced under these conditions. Incidence of B. cinerea sporulation on leaf discs was ca. 60% higher on leaves that emerged after the BCA application than on leaves directly exposed to BCA, indicating insufficient amount of the BCA had managed to spread to new leaves. Combinations of BCAs, whether applied simultaneously or sequentially (48 h apart), did not improve disease control over the most effective BCA within the combination applied alone. This indicated possible antagonism or interference between the BCAs. Results suggested that there was significant antagonism for most combinations of the three BCAs tested and the degree of antagonism increased as the time from BCA application to pathogen introduction lengthened.     

Biocontrol of strawberry fruit infected by Botrytis cinerea: Effects on the microbial communities on fruit assessed by next‐generation sequencing

Fruit grey mould, caused by the fungus Botrytis cinerea, is known to be a harmful disease of strawberry at postharvest stage. However, effects of an application of biological control agents (BCAs) on strawberry fruit in terms of shift in the microbial community are still unknown. The present research aimed to investigate the effects of an application of BCAs on postharvest microbial populations present on strawberry fruits. Strawberry plants were sprayed with three kinds of BCA, RhizoVital 42 fl. (Bacillus amyloliquefaciens FZB42), Trianum‐P (Trichoderma harzianum T22) and Naturalis (Beauveria bassiana ATCC 74040), targeting Botrytis cinerea fungus. Control plots were composed of water and fungicide treatments. Microbial communities (bacteria and fungi) were analysed via next‐generation sequencing on an Illumina MiSeq. Analysis of 16S RNA and ITS rRNA sequences indicated that the BCAs application modified both bacterial and fungal community compositions and diversity. An application of two BCAs together had more effects on microbial community composition than a single application. These results suggest that BCAs can modify bacterial and fungal community composition and diversity on strawberry fruits, which may consequently improve the efficiency and establishment of these products on control of postharvest diseases of fruits, such as grey mould.     

Natural and released inoculum levels of entomopathogenic fungal biocontrol agents in soil in relation to risk assessment and in accordance with EU regulations

Entomopathogenic fungi being developed as biological control agents (BCAs) may have the potential to spread and become established in the environment. For registration purposes, the risks concerning their persistence have to be evaluated according to EU legislation which requires the decline of BCAs to acceptable background levels unless related risks are acceptable. In order to deal with this requirement, applicants of a BCA need to give information on its persistence and natural background levels. For risk assessors and registration authorities guidance on how to evaluate data on natural background levels of indigenously occurring species (=same species as the introduced BCA) is needed. For this purpose, an overview is presented on background levels of some indigenous fungi as well as persistence data of some applied fungal BCAs. Data were restricted to commerical species. It was found that for the species Metarhizium anisopliae, Beauveria bassiana and Beauveria brongniartii natural densities were relatively low and introduced strains of these fungi decreased gradually in time. Many factors were found in the literature, such as intrinsic, edaphic, biotic, climatic, and cultural factors, that could explain this decline.     

Distribution of a model biocontrol agent (Serenade® MAX) in apple and pear by mason bees and bumble bees

1. Biocontrol agents (BCAs) are commonly sprayed on flowering pipfruit trees to prevent them from getting infected by various pathogens. By entomovectoring, BCAs can be directly delivered onto the flowers. However, we currently lack knowledge on the distribution dynamics of BCAs by pollinators.
2. Here, managed bees, both bumble bees (Bombus terrestris) and mason bees (Osmia bicornis and Osmia cornuta), were placed in the vicinity of flowering pipfruit trees (pear -‘Conference’, and apple—‘Svatava’ and ‘Jonagold’), and this allowed us to investigate the distribution of a model BCA, namely, Serenade® MAX, from spray-inoculated flowers of a centralized tree to non-inoculated flowers of surrounding receiver trees by bees in an experimental setup in outdoor conditions.
3. One hour after inoculation, we detected an enrichment of BCA in the flowers of the receiver trees and this for each tested pipfruit.
4. The distribution of BCA from treated to untreated flowers was homogenous between the receiver trees for ‘Svatava’, while significantly different loads were detected for both ‘Conference’ and ‘Jonagold’, which might be due to differences in environmental factors, and/or bee characteristics.
5. More research is needed to understand the distribution dynamics of BCAs by pollinators in field conditions, such as in commercial orchards or crop fields, and how this could result in an efficient control.

     

Field management of Sclerotinia stem rot of soybean using biological control agents

Biological control agents (BCAs) were evaluated for their efficacy on reducing the number of sclerotia of Sclerotinia sclerotiorum (Lib.) de Bary in the soil and on Sclerotinia stem rot in soybean production systems in Michigan. BCAs included Coniothyrium minitans CON/M/91–08 (Product name: Contans®WG), Streptomyces lydicus WYEC 108 (Actinovate®AG), Trichoderma harzianum T-22 (PlantShield®HC), and Bacillus subtilis QST 713 (Serenade®MAX). At two field locations, soil artificially infested with S. sclerotiorum sclerotia, was treated by incorporating the above BCAs in the topsoil before planting and boscalid was applied as a foliar fungicide at growth stage R1 as a positive control. C. minitans was the most effective BCA and reduced the disease severity index (DSI) by 68.5% and the number of sclerotia of S. sclerotiorum in the soil by 95.3%. S. lydicus and T. harzianum reduced DSI by 43.1% and 38.5% and sclerotia in soil by 90.6% and 70.8%, respectively. B. subtilis only had a marginal effect on S. sclerotiorum. Populations of Bacillus, Streptomyces, Trichoderma spp., and C. minitans collected from soil samples and at 3, 28, 71, and 169 days after BCA application indicated that the population of Streptomyces, Trichoderma spp., and C. minitans did not change significantly throughout the season, which may be the reason for their effectiveness.     

Evaluation of isolates of Trichoderma,Pseudomonas and Bacillus species as treatment for the control of post-harvest fungal rot disease of yam (Dioscorea spp.)

The efficacy of four biological control agents (BCAs): Trichoderma asperellum strain NGT158, T. longibrachiatum strain NGT167, Bacillus subtilis and Pseudomonas fluorescens for the management of post-harvest tuber rot among four yam species, Dioscorea rotundata, D. cayenensis, D. alata, and D. dumetorum was evaluated. Rotted yam tubers were collected across three agroecological zones in Nigeria to isolate six infecting fungal pathogens: Aspergillus niger, Lasiodiplodia theobromae, Rhizoctonia solani, Penicillium oxalicum, Fusarium oxysporum and Sclerotium rolfsii. The BCAs were isolated by serial dilution and rot inhibition of treated tubers was evaluated using destructive sampling method in vivo after six months of storage. Bacillus subtilis was generally most effective, especially when applied 24 h before the inoculation of test pathogens across the four yam species, with percent inhibition that ranged between 47.8 and 81.2%. However, the four BCAs showed good potential in the control of the fungal pathogens causing post-harvest yam rot.     

Effects on Diversity of Soil Fungal Community and Fate of an Artificially Applied Beauveria bassiana Strain Assessed Through 454 Pyrosequencing

The entomopathogenic fungus Beauveria bassiana is widely used as a biological control agent (BCA) for insect pest control, with fungal propagules being either incorporated into the potting media or soil or sprayed directly onto the foliage or soil. To gain a better understanding of entomopathogenic fungal ecology when applied as a BCA to the soil environment, a case study using tag-encoded 454 pyrosequencing of fungal ITS sequences was performed to assess the fate and potential effect of an artificially applied B. bassiana strain on the diversity of soil fungal communities in an agricultural field in India. Results show that the overall fungal diversity was not influenced by application of B. bassiana during the 7 weeks of investigation. Strain-specific microsatellite markers indicated both an establishment of the applied B. bassiana strain in the treated plot and its spread to the neighboring nontreated control plot. These results might be important for proper risk assessment of entomopathogenic fungi-based BCAs.     

Biological control of onion leaf blight disease by bulb and foliar application of powder formulation of antagonist mixture

Abstract

Three antagonists: Pseudomonas fluorescens (Pf1), Bacillus subtilis and Trichoderma viride, were tested alone and in combination for suppression of onion leaf blight (Alternaria palandui) disease under glasshouse and field conditions. The average mean of disease reduction was 24.81% for single strains and 42.44% for mixtures. In addition to disease suppression, treatment with a mixture of antagonists promoted plant growth in terms of increased plant height and ultimately bulb yield. Though seed treatment of either single strain or strain mixtures alone could reduce the disease, subsequent application to root, leaves or soil further reduced the disease and enhanced the plant growth. The mixture consisting of Pseudomonas fluorescens Pf1 plus Bacillus subtilis plus Trichoderma viride was the most effective in reducing the disease and in promoting plant growth and bulb yield in greenhouse and field tests.     

Evaluation of arbuscular mycorrhiza and other biocontrol agents in managing Fusarium oxysporum f. sp. Cubense infection in banana cv. Neypoovan

Panama wilt of banana caused by Fusarium oxysporum f. sp. cubense (race 1) is a serious disease devastating the important cultivar Neypoovan (syn Elakki Bale AB) in southern India. Chemical control methods are not very effective in controlling the disease. The objective of this study was to evaluate biocontrol agents (BCAs) under controlled and field conditions for their efficacy against the pathogen and to detect and quantify the reduction in FOC population. Arbuscular mycorrhizal (AM) fungi, Trichoderma harzianum and Pseudomonas fluorescens were inoculated at the time of planting in single, dual and tripartite combinations allowing colonization up to 0, 45 and 90 days. Plants were challenged thereafter with 50 g of FOC inoculum multiplied on sorghum grains containing 1.5×10⁶ cfu g^?1. Uninoculated plants and those inoculated with pathogen only were controls. Plant growth parameters were measured and structural modifications in the roots were studied. FOC populations in the roots were determined by ELISA every month and final yield was recorded. At the end of 7 months, plants pre-inoculated with BCAs i.e., G. mosseae+T. harzianum and challenged with Fusarium under field conditions could sustain 61 and 70% improvement in plant height and girth, respectively, and 75% in bunch weight over plants not precolonised with BCAs but challenged with FOC which finally succumbed to the disease. ELISA study revealed Fusarium population was reduced to 0.58 OD in 7 months in G. mosseae and T. harzianum treatment compared to a level of 1.9 OD in Fusarium alone treated plants. Beneficial effect of BCAs may be due to the over all protection provided by them by causing physical modifications in the cell wall, growth promotion and through induction of disease resistance.     

Suppression of tan spot and plant growth promotion of wheat by synthetic and biological inducers under field conditions

Tan spot of wheat caused by Pyrenophora tritici‐repentis (Ptr) is a major leaf spot disease. No single control measure is likely to be successful in controlling tan spot and a fully integrated system of disease management is more likely to achieve a long‐term solution. Research to improve control efficacy has focused on fungicide improvement, resistant cultivars, the use of biological control agents (BCAs) mixtures and combinatorial approaches involving BCAs and plant resistance stimulants with complementary modes of action. Various biotic and abiotic agents can stimulate wheat defence mechanisms and so benefit resistance to Ptr infection. Among them, Trichoderma spp. have been widely used as antagonistic fungal agents against several pathogens as well as plant growth enhancers. Also, the synthetic agents acibenzolar‐S‐methyl (ASM) and thiamethoxam (TM) have provided broad‐spectrum disease and pest control as well as enhanced plant vigour against several fungal diseases. The aim of this research was to evaluate the effectiveness of two Trichoderma harzianum strains and two substances of synthetic origin (ASM and TM) on the suppression of tan spot and plant growth promotion of wheat plants. When BCAs, ASM and TM were applied to field plots on wheat cultivar Klein Escorpion, the severity of tan spot reduced and plant height, fresh weight, dry weight of shoots and dry weight of roots increased in comparison with the control. When applied prior to Ptr inoculation, ASM, TM and the strain Th1 of T. harzianum caused a reduction in necrotic lesions >50% compared to the control treatment. Seed treatment with TM resulted in a significant enhancement of plant height. Application of ASM significantly increased foliar fresh weight by 45% as compared to the control treatment, whereas foliar fresh weight increased 29% and 50% when TM and T. harzianum strain Th1 were applied as seed coating. Acibenzolar‐S‐methyl alone or combined with Th1 increased dry weight to >60%, whereas the effects of TM and Th1 on dry mass showed an increase that ranged from 57% to 25%. Plants treated with Th1 and both synthetic compounds achieved up to sixfold increment in root dry weight over the control.     

Significance of ecology in the development of biocontrol agents against soil‐borne plant pathogens

Approaches to the development of inoculant biocontrol agents (BCAs) of soil‐borne pathogens are discussed. Based on an analysis of the success of Peniophora (Phlebia) gigantea and Agrobacterium radiobacter it is argued that most subsequent attempts to develop inoculant BCAs have failed because the organisms were selected for in vitro antagonism but were ecologically unsuited to the environments where pathogens grow. The reported modes of action of BCAs are reviewed and in some cases reinterpreted. It is argued that antibiosis and some types of mycoparasitism have not been shown to be direct mechanisms of biocontrol in vivo; they might, instead, facilitate competition for substrates or sites as the primary mechanism of control. The ecology of BCAs in general is reviewed, with emphasis on interactions in microsites and the design of appropriate screening strategies. Specific examples are used to illustrate these points.     

The use of yeasts for biological control of the plant pathogen Sclerotinia sclerotiorum

Yeasts are promising biological control agents(BCAs) for a number of plant diseases. Studieswere carried out to evaluate various adjuvantsand nutrients for their ability to supportgrowth of a yeast BCA (Cryptococcusalbidus). Hydroxyethylcellulose (HEC) andinvert emulsions were found to stimulate growthof C. albidus in vitro. Severalcommercial spray adjuvants were compatible withC. albidus although they did not markedlystimulate growth. Other adjuvants were lethalto the yeast. In controlled environmentand field trials, the yeasts C. albidusand Pichia anomala provided low levels ofcontrol of white mould, a disease of bean (Phaseolus vulgaris) caused by the fungus Sclerotinia sclerotiorum. However, they weregenerally inferior in performance when comparedto either the biocontrol fungus Epicoccumnigrum or to the fungicide iprodione.     

Potential of soil-derived fungal biocontrol agents applied as a soil amendment and a seed coating to control Verticillium wilt of sugar beet

Verticillium dahliae (Vd) is an emerging threat to sugar beet production. Control measures such as fungicides are not available and the utilisation of resistant cultivars is very limited. Hence, we explored the potential of two soil-derived fungal biocontrol agents (BCAs), Fusarium oxysporum F2 (FoF2) and Verticillium tricorpus 1808 (Vt1808), against Verticillium wilt of sugar beet. Pathogenicity tests revealed that Vd caused over 90% disease incidence and severity and led to a significant yield reduction, whereas BCAs neither inhibited nor promoted plant growth. Germination rate was higher in BCA-treated seeds compared to untreated ones. Viability of both BCAs was significantly reduced after six months of storage in liquid methylcellulose formulation (MC), while BCA concentrations remained stable on stored seeds treated with MC. In contrast, Vt1808 produced in sand-rye flour formulation remained 100% viable after storage. Similarly, post-storage analysis of the FoF2 talcum powder formulation revealed improved colony forming units, but increments were not significant. In vitro, both BCAs caused no growth inhibition zones and only insignificant Vd growth reductions were observed. In the greenhouse, soil amendment with a higher dose of FoF2:Vt1808 mixture resulted in substantial reductions of disease severity on the crown (33.3%), disease incidence (55.6%) and disease severity (68.8%) on the beet as well as an improved yield (32.9%). In contrast, seed coating did not reduce symptoms on the crown and on the beet. In the field, both BCAs did not provide significant disease reductions. Nevertheless, a promising result was achieved with the application of FoF2. Despite the need for improvement of the biocontrol activity, the results of this study demonstrate the suitability of the optimised BCA formulations for utilisation in commercial sugar beet production.     

Screening tomato-associated bacteria for biological control of grey mold on tomato

Aiming at discovering effective biocontrol agents (BCAs) against grey mold on tomato caused by Botrytis cinerea Pers., we selected 819 bacterial isolates from the surface as well as the interior of the roots, stems, and leaves of tomato plants grown in B. cinerea-infested fields. In a dual-culture assay, 116 isolates (14.16%) showed antagonism against B. cinerea and fewer ones against five additional tomato-associated fungal pathogens – Pythium ultimum, Phytophthora capsici, Fusarium oxysporum f. sp. lycopersici, Sclerotinia sclerotiorum and Ralstonia solanacearum. Thirty-one isolates with antagonism to B. cinerea and at least one of the five additional pathogens were assessed for their efficacy in controlling grey mold on tomato in a greenhouse test. Thirteen of them attained the efficacy over 50% and were subjected to the second greenhouse test, in which 12 isolates consistently accomplished the biocontrol efficacy over 50%, with isolates ABc28 and ABc22 achieving the efficacy of 66.71% and 64.90%, respectively. Under greenhouse conditions, the above two as well as isolates ABc2, ABc11 and ABc17 increased tomato biomass by more than 20% in comparison with the control. The 12 antagonistic isolates accomplishing the biocontrol efficacy over 50% in both greenhouse tests were considered potential BCAs against grey mold, which were identified as Pseudomonas spp., Pantoea spp., Bacillus spp. and Chryseobacterium spp. Ten of them were found to produce at least one of the three hydrolytic enzymes (protease, cellulase and chitinase) and/or siderophore, which might be involved in their mechanisms of suppressing the disease. Based on the origin of these 12 strains, the leaf tissue, especially the leaf interior, of tomato plants grown in a B. cinerea-infested field appears to be a good source of potential BCAs against grey mold.     

High-throughput assay for optimising microbial biological control agent production and delivery

Lack of technologies to produce and deliver effective biological control agents (BCAs) is a major barrier to their commercialisation. A myriad of variables associated with BCA cultivation, formulation, drying, storage and reconstitution processes complicate agent quality maximisation. An efficient assay using a 96-well microplate format to allow an integrated approach to optimising these process variables is presented. The assay involves growing the BCA of interest in flasks or fermentors, formulating cells harvested from growth cultures, delivering microlitre droplets of formulated cells to microplate wells, air-drying droplets, storing plates, reconstituting dried cells and monitoring the rate of cell growth to a specified yield using a plate-reading spectrophotometer. Spectrophotometer assessments of cell activity were significantly correlated with microdilution plate viable cell enumeration. Relevant variables (culture harvest age, cultivation and formulation ingredients, storage atmosphere and temperature) were tested with each step of the assay process to view their individual and combined impact on resultant microbial activity. The utility of this method to evaluate many treatments was demonstrated on seven strains of Pseudomonas fluorescens and Enterobacter cloacae known to suppress fungal diseases of wheat and potatoes.     

Evaluation of biocontrol agents and potassium silicate for the management of powdery mildew of zucchini

Investigations were conducted under greenhouse and field conditions to evaluate the effects of potential biocontrol agents (BCAs) and soluble silicon (Si) on powdery mildew of zucchini caused by Podosphaera xanthii. Five BCAs were applied as foliar sprays to zucchini leaves and Si was drenched weekly into the rhizosphere of these plants.In the greenhouse, all BCAs provided significant control of powdery mildew with fungal isolates, reducing disease levels by up to 90%. Si alone reduced powdery mildew by as much as 35% and improved the efficacy of most of the biocontrol agents. Higher disease pressure reduced the efficacy of Si on powdery mildew but did not affect the performance of the BCAs. In the field, a disease reduction of 10–70% was achieved by BCAs and Si. Lower temperatures and high humidity ranges were suitable for optimal performances. The efficacy of the bacterial BCA, Serratia marcescens – B15 and silicon diminished at temperatures above 25 °C. The fungal BCAs (Clonostachys rosea – EH and Trichothecium roseum – H20) were better suited to higher temperatures (25–30 °C) and were tolerant of low RH values. Application of K₂SiO₂ to zucchini roots increased the level of Si in the leaves, which was responsible for suppression of the disease.     

A baseline study using Plantwise information to assess the contribution of extension services to the uptake of augmentative biological control in selected low- to lower- middle- income countries

The uptake of augmentative biological control agents (BCAs) is still limited, particularly in many low- to lower- middle- income countries. This study focuses on factors that affect the uptake of BCAs for arthropod pests by national extension partners (NEPs) in Plantwise—an agricultural development programme facilitating the establishment of plant clinics where farmers can obtain diagnosis and plant health advice. Using data generated by NEPs, BCA recommendations in extension material and given by extension workers in Ghana, Kenya, Zambia, India, Nepal and Pakistan were analysed. The rate of BCA recommendation ranged from 13.0 (Zambia) to 61.1% (India) in extension materials and from 0.0 (Zambia) to 18.2% (India) in recommendations given by extension workers. Knowledge, availability and price were identified as the main factors affecting the uptake of BCAs by NEPs. This baseline study gives novel insight into the potential of NEPs to facilitate the use of BCAs.     

Optimization of different application methods of multi-facial bacterial and fungal antagonists against sheath blight pathogen of rice,Rhizoctonia solani AG1-IA

Relative effectiveness of seven different application methods of five native bacterial and fungal biocontrol agents (BCAs) and one fungicide (azoxystrobin) was evaluated against Rhizoctonia solani, under pot and field conditions on rice cultivar Pusa Sugandha-5. Plants grown in pots infected with R. solani suffered a 30%–49% decrease in plant growth and yield of grain. However, treatment with BCAs reduced the adverse effect of the pathogen but significantly varied with the treatment schemes. Amongst the treatments, soil application (SA) at 20 + 40 days after planting (DAP) followed by foliar application (FA) at 60 DAP was recorded as most efficacious, and reduced the severity of disease by 42–68%, resulting in a 21–36% plant growth promotion and yield enhancement. Treatment comprising SA 20 + FA 40 DAP was next in effectiveness but statistically equal to seed priming (SP) + SA 40 DAP of treatment. Amongst the BCAs, Pseudomonas putida was shown to be the most efficient, trailed by Trichoderma harzianum, P. fluorescens, T. viride and Bacillus subtilis. Field trials under naturally infested fields have also validated the effectiveness of P. putida. The SA 20 + 40 + FA 60 DAP with P. putida and T. harzianum were found quite effective and decreased the disease severity and incidence (40–81%), and improved the grain yield (42–72%). Relatively lower ShB control was recorded with SA 20 + FA 60 DAP, however, it was statistically at par with SA 20 DAP treatment and equal to SA 20 + FA 40 DAP.     

Development of Australian commercial producers of invertebrate biological control agents from 1971 to 2014

The Australian industry producing invertebrate biological control agents (BCAs) commercially was described for the first time through interviews with company owners, citrus pest management researchers and citrus growers. This industry started with citrus pest management in 1971. Over 40 years it expanded from one company and one commercial BCA to peak at nine companies operating from 2002 to 2010. A period of consolidation resulted in five companies producing 36 commercial BCAs in 2014. Annual gross sales were <AU$10 million compared to >AU$400 million spent on insecticides. Barriers to industry growth included high costs of developing new commercial BCAs partly due to regulatory costs associated with importation of new BCAs into Australia, and low adoption of commercial BCAs due to limited access to information and training. The industry responded to these barriers by collaborating with stakeholders to develop new commercial BCAs, and developing an accreditation scheme to build technical capacity and encourage adoption.     

Biological control of rice sheath blight using hyphae-associated bacteria: development of an <Emphasis Type="Italic">in planta</Emphasis> screening assay to predict biological control agent performance under field conditions

A pathogenicity assay for in planta screening of biological control agents (BCAs) towards sheath blight in rice was developed, and used to evaluate a panel of Rhizoctonia solani Kühn hyphae-associated bacteria for their ability to control sheath blight under screenhouse conditions. The best performing BCA, Burkholderia sp. strain A-7.3, was selected for field trials. Disease incidence and disease severity were significantly reduced leading to a significant grain yield increase of 7%. Furthermore, R. solani sclerotia formation and sclerotia viability were significantly reduced, thus lowering the reservoir for primary infections in the next crop cycle. The paper presents a reliable pathogenicity assay that can be used to test BCA performance under different scenarios e.g. plant variety and soil conditions, and help predict translation of results obtained under screenhouse conditions to field performance. Furthermore, it supports the hypothesis that hyphae-associated bacteria are a promising source of niche-specific BCAs towards fungal pathogens.