The Influence of pH on Biodeterioration of a Tropical Timber Exposed to Mixed Cultures of Biocontrol and Wood-Rot Fungi

A laboratory investigation of the decay control potentials of Trichoderma viride and Penicillium sp. on the deterioration of obeche wood (Triplochiton scleroxylon). buffered at various pH. by wood-rot fungi ( Gloeophyllum sp. and Gloeophyllum sepiarium ), was carried out. Biomass determinations in carboxylmethyl cellulose broth at various pH showed that the biocontrol fungal strains exployed grew better as the pH approached neutral while the reverse was true for the wood-rot fungi. Deterioration of wood (buffered at various pH) simultaneously inoculated with the biocontrol and wood-rot fungi was more markedly reduced towards neutral pH than at lower pH values. Decay begun in wood initially infested with rot fungi before inoculation with biocontrol fungi was virtually halted at neutral pH. which was not the case in lower pH (2 and 3) buffered wood simultanecously inoculated with biocontrol and wood-rot fungi. A killing effect was indicated when the rot fungi failed to appear on potato–dextrose agar from interior sections of the wood blocks. Manipulation of pH may prove important in biological control of wood decay.     

Is Use of Both Pulpwood and Logging Residues Instead of Only Logging Residues for Bioenergy Development a Viable Carbon Mitigation Strategy?

This study adopts an integrated life-cycle approach to assess overall carbon saving related with the utilization of wood pellets manufactured using pulpwood and logging residues for electricity generation. Carbon sequestered in wood products and wood present in landfills and avoided carbon emissions due to substitution of grid electricity with the electricity generated using wood pellets are considered part of overall carbon savings. Estimated value of overall carbon saving is compared with the overall carbon saving related to the current use of pulpwood and logging residues. The unit of analysis is a hectare of slash pine (Pinus elliottii) plantation in southern USA. All carbon flows are considered starting from forest management to the decay of wood products in landfills. Exponential decay function is used to ascertain carbon sequestered in wood products and wood present in landfills. Non-biogenic carbon emissions due to burning of wood waste at manufacturing facilities, wood pellets at a power plant, and logging residues on forestlands are also considered. Impacts of harvest age and forest management intensity on overall carbon saving are analyzed as well. The use of pulpwood for bioenergy development reduces carbon sequestered in wood products and wood present in landfills (up to 1.6 metric tons/ha) relative to a baseline when pulpwood is used for paper making and logging residues are used for manufacturing wood pellets. Avoided carbon emissions because of displacement of grid electricity from the electricity generated using wood pellets derived from pulpwood fully compensate the loss of carbon sequestered in wood products and wood present in landfills. The use of both pulpwood and logging residues for bioenergy development is beneficial from carbon perspective. Harvest age is more important in determining overall carbon saving than forest management intensity.     

Molecular genetic tools to infer the origin of forest plants and wood

Most forest tree species exhibit high levels of genetic diversity that can be used to trace the origin of living plants or their products such as timber and processed wood. Recent progress to isolate DNA not only from living tissue but also from wood and wood products offers new opportunities to test the declared origin of material such as seedlings for plantation establishment or timber. However, since most forest tree populations are weakly differentiated, the identification of genetic markers to differentiate among spatially isolated populations is often difficult and time consuming. Two important fields of “forensic” applications are described: Molecular tools are applied to test the declared origin of forest reproductive material used for plantation establishment and of internationally traded timber and wood products. These applications are illustrated taking examples from Germany, where mechanisms have been developed to improve the control of the trade with forest seeds and seedlings, and from the trade with wood of the important Southeast Asian tree family Dipterocarpaceae. Prospects and limitations of the use of molecular genetic methods to conclude on the origin of forest plants, wood, and wood products are discussed.     

Impact of Norway spruce pre-degradation stages induced by Gloeophyllum trabeum on fungal and bacterial communities

In forest ecosystems, fungi are the key actors in wood decay. They have the capability to degrade lignified substrates and the woody biomass of coniferous forests, with brown rot fungi being common colonizers. Brown rots are typically involved in the earliest phase of lignocellulose breakdown, which therefore influences colonization by other microorganisms. However, few studies have focused on the impact of introducing decayed wood into forest environments to gauge successional colonization by natural bacterial and fungal communities following partial decay. This study aimed to address this issue by investigating the bacterial and fungal colonization of Norway spruce (Picea abies) wood, after intermediate and advanced laboratory-based, pre-decay, by the brown rot fungus Gloeophyllum trabeum. Using Illumina metabarcoding, the in situ colonization of the wood blocks was monitored 70 days after the blocks were placed on the forest floor and covered with litter. We observed significant changes in the bacterial and fungal communities associated with the pre-decayed stage. Further, the wood substrate condition acted as a gatekeeper by reducing richness for both microbial communities and diversity of fungal communities. Our data also suggest that the growth of some fungal and bacterial species was driven by similar environmental conditions.     

Antioxidants and iron chelators inhibit oxygen radical generation in fungal cultures of plant pathogenic fungi

Eutypa dieback and Esca are serious fungal grapevine trunk diseases (GTDs). Eutypa dieback is caused by Eutypa lata (Elata), and is often associated Phaeoacremonium minimum (Pmin), and Phaeomoniella chlamydospora (Pch) which are also important contributors to Esca disease.Understanding the complex pathogenesis mechanisms used by these causative fungi may potentially lead targeted treatments for GTDs in the future. Elata has been reported as a wood decay “soft rot” fungus and understanding of Elata’s pathogenesis chemistries can aid in controlling GTDs. Recent work that suggests that Pmin and Pch may contribute to pathogenesis by stimulating hydroxyl radical generation via secretion of low molecular weight phenolic metabolites. Building on these findings, we tested a hypothesis that antioxidants and chelators, and biocontrol agents that have been reported to secrete antioxidants and low molecular weight chelators, may inhibit the growth and activity of these fungi. Butylated hydroxy anisole (BHA) and butylated hydroxytoluene (BHT) were tested as antioxidant/chelators. BHA was found to be a highly effective control measure for the three pathogenic fungi tested at concentrations >0.5 mM. The biocontrol species Bacillus subtilis and Hypocrea (Trichoderma) atroviride were also tested, with both H. atroviride and B. subtilis effectively inhibiting growth of the three GTD fungi.     

Assessment of the biocontrol potential of a Trichoderma viride isolate: Part II: Protection against soft rot and basidiomycete decay

A previous paper reported on the establishment of a field and fungal cellar trial set up to determine the biocontrol potential of a specific Trichoderma isolate against wood decay fungi. This paper reports on the analyses used to examine the protective effect of the selected isolate, and presents results indicating an initial protective effect against both basidiomycetes and soft rot fungi. The parameters assessed in the field and fungal cellar trials were soft rot decay, basidiomycete decay, Trichoderma colonisation, moisture content and nitrogen content. The results of these analyses show that the introduction of a biological control agent has had a significant effect on moisture content, decay and nitrogen content. A protective effect has been observed against soft rot and basidiomycete decay fungi in field samples.     

Accurate forest projections require long‐term wood decay experiments because plant trait effects change through time

Whether global change will drive changing forests from net carbon (C) sinks to sources relates to how quickly deadwood decomposes. Because complete wood mineralization takes years, most experiments focus on how traits, environments and decomposer communities interact as wood decay begins. Few experiments last long enough to test whether drivers change with decay rates through time, with unknown consequences for scaling short‐term results up to long‐term forest ecosystem projections. Using a 7 year experiment that captured complete mineralization among 21 temperate tree species, we demonstrate that trait effects fade with advancing decay. However, wood density and vessel diameter, which may influence permeability, control how decay rates change through time. Denser wood loses mass more slowly at first but more quickly with advancing decay, which resolves ambiguity about the after‐life consequences of this key plant functional trait by demonstrating that its effect on decay depends on experiment duration and sampling frequency. Only long‐term data and a time‐varying model yielded accurate predictions of both mass loss in a concurrent experiment and naturally recruited deadwood structure in a 32‐year‐old forest plot. Given the importance of forests in the carbon cycle, and the pivotal role for wood decay, accurate ecosystem projections are critical and they require experiments that go beyond enumerating potential mechanisms by identifying the temporal scale for their effects.     

Association between myxomycetes and the decay stage of coarse woody debris in an evergreen broadleaf forest in warm temperate Japan

Myxomycetes inhabit coarse woody debris in varying stages of decay; however, their ecology in the dead wood of evergreen broadleaf trees is not well known. In this study, we examined the relationships between myxomycete species and the decay stage of wood from fallen trees in an evergreen broadleaf forest in Japan. Myxomycete species richness and abundance were calculated for eight stages of decay in fallen logs, according to the appearance and wood hardness of log portions. A total of 70 myxomycete species (including varieties) were found on the logs. Moderately decayed wood was the preferred habitat of myxomycetes (57 species; 81% of the total) and most species inhabited moist decayed wood. Analysis by nonmetric multidimensional scaling enabled the differentiation of myxomycete assemblages, with five groupings recognized across the progression of decay. Forty-two species preferred a particular decay stage, represented by the decay index. Physarum viride and Stemonitis splendens particularly preferred the less-decayed wood and Stemonitopsis typhina var. similis especially inhabited the well-decayed wood. Species from the order Physarales dominated the less-decayed wood, whereas Trichiales and Liceales species dominated the softer well-decayed wood. Myxomycetes diversity was high in and varied among logs with various stages of decay in a typical Japanese evergreen forest.     

Wood decomposition is more strongly controlled by temperature than by tree species and decomposer diversity in highly species rich subtropical forests

While the number of studies on the role of biodiversity on ecosystem functioning is steadily increasing, a key component of biogeochemical cycling in forests, dead wood decay, has been largely neglected. It remains widely unknown whether and how dead wood decay is affected by diversity loss in forests. We studied the hierarchical effects of tree species diversity on wood decay rates in a subtropical forest landscape in southeast China via its influence on fungal OTU richness and invertebrate diversity using piecewise structural equation models. The experiment was conducted in natural forest plots that span a wide gradient of tree species diversity embedded in a heterogeneous topography. To account for interactions between macro‐invertebrates and fungi, that potentially modify the influence of tree biodiversity and climate on dead wood decay, we compared a macro‐invertebrate exclusion treatment with a control treatment that allowed access to all types of decomposers. Diversity effects of trees on wood decay rates were mostly negative and mediated by the diversity of macro‐invertebrates. However, the effects of tree species diversity or fungal OTU richness and macro‐invertebrate diversity on wood decay rates were comparatively weak. Temperature affected decay rates positively and had the strongest influence in all treatments. While the exclusion of macro‐invertebrates did not lead to a reduction of wood decay rates, our results suggest that they may however have a mediating role in the process. In the presence of invertebrates the predictability of wood decay rates was higher and we observed a tendency of a stronger temperature control. Our results suggest that there is evidence for diversity effects on wood decomposition, but the temperature control is still more important. Thus, an increase in mean annual temperature will increase carbon and nutrient turnover through wood decomposition in subtropical forest irrespective of biotic composition.     

Monitoring indole alkaloid production by Penicillium digitatum during infection process in citrus by Mass Spectrometry Imaging and molecular networking

Green mold, caused by Penicillium digitatum, is the most destructive post-harvest disease in citrus. Secondary metabolites produced by fungal phytopathogens have been associated with toxicity to their respective host through the interaction with a wide range of cell targets. Natural products have also been described as important molecules for biocontrol and competition in their respective environment. For P. digitatum, the production of indole alkaloids, tryptoquialanines A and B, have been reported. However, their biological role remains unknown. Mass Spectrometry Imaging (MSI) technique was applied here for the first time to monitor the secondary metabolites produced on the orange surface during infection in order to gain insights about the P. digitatum-citrus interaction mechanisms. Through the combination of MSI and molecular networking it was possible to report, for the first time, the production of tryptoquivalines and fumiquinazolines by P. digitatum and also the accumulation of tryptoquialanines on the fruit surface from 4 to 7 d post inoculation. P. digitatum was also evaluated concerning the ability to sinthesize indole alkaloids in vivo in the different citrus hosts. The biological role of tryptoquialanines was investigated and tryptoquialanine A was submitted to insecticidal bioassays that revealed its high toxicity against Aedes Aegypti, suggesting an important insecticidal action during orange decay.     

Biocontrol of Postharvest Rhizopus Decay of Peaches with Pichia caribbica

A new yeast antagonist, Pichia caribbica, isolated in our laboratory from the soil collected from unsprayed orchards, was evaluated for its biocontrol capability against Rhizopus stolonifer on peaches and the possible mechanisms involved. The decay incidence and lesion diameter of Rhizopus decay of peaches treated by P. caribbica were significantly reduced compared with the control fruits, and the higher the concentration of P. caribbica, the better the efficacy of the biocontrol. Rapid colonization of the yeast in peach wounds stored at 25 °C was observed. In peaches, the activities of peroxidase (POD), catalase (CAT), and phenylalanine ammonia-lyase (PAL) were significantly induced by P. caribbica treatment compared to those of the control fruits. All these results indicated that P. caribbica has a great potential for the development of commercial formulations to control postharvest Rhizopus decay of peaches. Its modes of action were based on competition for space and nutrients with pathogens, inducement of activities of defense-related enzymes such as POD, CAT, and PAL of peaches.     

Simulated nitrogen deposition affects wood decomposition by cord-forming fungi

Anthropogenic nitrogen (N) deposition affects many natural processes, including forest litter decomposition. Saprotrophic fungi are the only organisms capable of completely decomposing lignocellulosic (woody) litter in temperate ecosystems, and therefore the responses of fungi to N deposition are critical in understanding the effects of global change on the forest carbon cycle. Plant litter decomposition under elevated N has been intensively studied, with varying results. The complexity of forest floor biota and variability in litter quality have obscured N-elevation effects on decomposers. Field experiments often utilize standardized substrates and N-levels, but few studies have controlled the decay organisms. Decomposition of beech (Fagus sylvatica) blocks inoculated with two cord-forming basidiomycete fungi, Hypholoma fasciculare and Phanerochaete velutina, was compared experimentally under realistic levels of simulated N deposition at Wytham Wood, Oxfordshire, UK. Mass loss was greater with P. velutina than with H. fasciculare, and with N treatment than in the control. Decomposition was accompanied by growth of the fungal mycelium and increasing N concentration in the remaining wood. We attribute the N effect on wood decay to the response of cord-forming wood decay fungi to N availability. Previous studies demonstrated the capacity of these fungi to scavenge and import N to decaying wood via a translocating network of mycelium. This study shows that small increases in N availability can increase wood decomposition by these organisms. Dead wood is an important carbon store and habitat. The responses of wood decomposers to anthropogenic N deposition should be considered in models of forest carbon dynamics.     

Modification of wood with Si compounds to limit boron leaching from treated wood and to increase termite and decay resistance

In this study, we tested tetraethoxysilane and methyltriethoxysilane as modifying silicon-based compounds for their potential to limit boron leachability from modified wood and to increase biological durability of the wood against fungi and termites. Both the silane compounds were used in silane state where acidified ethanol was added and stirred at ambient temperature for 30 min. We used two different processes for preservative treatments: double treatment and single treatment. In double treatment, the specimens from sugi wood were first treated with boric acid at 1% concentration and subsequently treated with the silanes. In single treatment, boric acid was mixed with the silane compounds in the silane state yielding 1% boric acid concentration. Subsequent to the treatments, wood specimens were subjected to laboratory leaching tests, and leachates were analyzed for boron content with an inductively coupled plasma (ICP) spectrometry. ICP analyses showed that silane treatments were able to limit boron leaching from treated wood by about 40% in all cases for each silane compound. Wood specimens were then subjected to laboratory termite and decay resistance tests using the subterranean termites, Coptotermes formosanus, and the wood decaying fungi, Fomitopsis palustris and Trametes versicolor. Termite and fungal decay resistance tests revealed that resistance of modified wood with the silane and boron compounds increased when compared to untreated and boron-only treated wood specimens. More in-depth studies on the mechanisms of interactions between the silicon compounds, boron elements and wood components are in progress.     

Edge effects on moisture reduce wood decomposition rate in a temperate forest

Forests around the world are increasingly fragmented, and edge effects on forest microclimates have the potential to affect ecosystem functions such as carbon and nutrient cycling. Edges tend to be drier and warmer due to the effects of insolation, wind, and evapotranspiration and these gradients can penetrate hundreds of metres into the forest. Litter decomposition is a key component of the carbon cycle, which is largely controlled by saprotrophic fungi that respond to variation in temperature and moisture. However, the impact of forest fragmentation on litter decay is poorly understood. Here, we investigate edge effects on the decay of wood in a temperate forest using an experimental approach, whereby mass loss in wood blocks placed along 100 m transects from the forest edge to core was monitored over 2 years. Decomposition rate increased with distance from the edge, and was correlated with increasing humidity and moisture content of the decaying wood, such that the decay constant at 100 m was nearly twice that at the edge. Mean air temperature decreased slightly with distance from the edge. The variation in decay constant due to edge effects was larger than that expected from any reasonable estimates of climatic variation, based on a published regional model. We modelled the influence of edge effects on the decay constant at the landscape scale using functions for forest area within different distances from edge across the UK. We found that taking edge effects into account would decrease the decay rate by nearly one quarter, compared with estimates that assumed no edge effect.     

Fungi associated with galleries of the emerald ash borer

The emerald ash borer (EAB) is an exotic forest pest that has killed millions of ash trees in the United States and Canada, resulting in an ecological disaster and billions of dollars in economic losses of urban landscape and forest trees. The beetle was first detected in Michigan in 2002 and has spread through much of the Eastern and Midwestern U.S., reaching Minnesota in 2009. Since then, it has spread across the state and poses a great risk to the more than 1 billion ash trees in Minnesota. The larval stage of EAB creates wounds on trees as they feed on the inner bark, causing disruption of water and sap flow that results in tree death. The fungal community associated with EAB larval galleries is poorly understood and the role these fungi may play in tree death is not known. This study describes fungi isolated from EAB larval galleries sampled throughout the main geographic areas of Minnesota where ash is affected by EAB. Fungal cultures were identified by extracting genomic DNA and sequencing the ITS region of the rDNA. Results from 1126 isolates reveal a diverse assemblage of fungi and three functional guilds comprised of canker pathogens, wood decay, and entomopathogenic fungi. The most common canker-associated genera were Cytospora followed by Phaeoacremonium, Paraconiothyrium, Coniothyrium, Nectria, Diplodia, and Botryosphaeria. Fungi in the Basidiomycota were nearly all wood decay causing fungi and many were species of pioneer colonizing genera including Sistotrema, Irpex, Peniophora, Phlebia and Ganoderma. Some of these fungi seriously affect urban trees, having the potential to cause rapid wood decay resulting in hazardous tree situations. Several entomopathogenic genera with the potential for biological control of EAB were also isolated from galleries. Purpureocillium was the most commonly isolated genus, followed by Beauveria, Clonostachys, Lecanicillium, Akanthomyces, Cordyceps, Microcera, Tolypocladium, and Pochonia. The results identify important fungal functional guilds that are occupying a new niche in ash trees resulting from EAB and include fungi that may accelerate decline in tree health, increase hazard tree situations, or may provide options for biological control of this destructive invasive insect.     

Relationships among wood‐boring beetles,fungi, and the decomposition of forest biomass

A prevailing paradigm in forest ecology is that wood‐boring beetles facilitate wood decay and carbon cycling, but empirical tests have yielded mixed results. We experimentally determined the effects of wood borers on fungal community assembly and wood decay within pine trunks in the southeastern United States. Pine trunks were made either beetle‐accessible or inaccessible. Fungal communities were compared using culturing and high‐throughput amplicon sequencing (HTAS) of DNA and RNA. Prior to beetle infestation, living pines had diverse fungal endophyte communities. Endophytes were displaced by beetle‐associated fungi in beetle‐accessible trees, whereas some endophytes persisted as saprotrophs in beetle‐excluded trees. Beetles increased fungal diversity several fold. Over forty taxa of Ascomycota were significantly associated with beetles, but beetles were not consistently associated with any known wood‐decaying fungi. Instead, increasing ambrosia beetle infestations caused reduced decay, consistent with previous in vitro experiments that showed beetle‐associated fungi reduce decay rates by competing with decay fungi. No effect of bark‐inhabiting beetles on decay was detected. Platypodines carried significantly more fungal taxa than scolytines. Molecular results were validated by synthetic and biological mock communities and were consistent across methodologies. RNA sequencing confirmed that beetle‐associated fungi were biologically active in the wood. Metabarcode sequencing of the LSU/28S marker recovered important fungal symbionts that were missed by ITS2, though community‐level effects were similar between markers. In contrast to the current paradigm, our results indicate ambrosia beetles introduce diverse fungal communities that do not extensively decay wood, but instead reduce decay rates by competing with wood decay fungi.     

Molecular database for classifying Shorea species (Dipterocarpaceae) and techniques for checking the legitimacy of timber and wood products

The extent of tropical forest has been declining, due to over-exploitation and illegal logging activities. Large quantities of unlawfully extracted timber and other wood products have been exported, mainly to developed countries. As part of the export monitoring effort, we have developed methods for extracting and analyzing DNA from wood products, such as veneers and sawn timbers made from dipterocarps, in order to identify the species from which they originated. We have also developed a chloroplast DNA database for classifying Shorea species, which are both ecologically and commercially important canopy tree species in the forests of Southeast Asia. We are able to determine the candidate species of wood samples, based on DNA sequences and anatomical data. The methods for analyzing DNA from dipterocarp wood products may have strong deterrent effects on international trade of illegitimate dipterocarp products. However, the method for analyzing DNA from wood is not perfect for all wood products and need for more improvement, especially for plywood sample. Consequently, there may be benefits for the conservation of tropical forests in Southeast Asia.     

Modeling decay rates of dead wood in a neotropical forest

Variation of dead wood decay rates among tropical trees remains one source of uncertainty in global models of the carbon cycle. Taking advantage of a broad forest plot network surveyed for tree mortality over a 23-year period, we measured the remaining fraction of boles from 367 dead trees from 26 neotropical species widely varying in wood density (0.23–1.24 g cm⁻³) and tree circumference at death time (31.5–272.0 cm). We modeled decay rates within a Bayesian framework assuming a first order differential equation to model the decomposition process and tested for the effects of forest management (selective logging vs. unexploited), of mode of death (standing vs. downed) and of topographical levels (bottomlands vs. hillsides vs. hilltops) on wood decay rates. The general decay model predicts the observed remaining fraction of dead wood (R ² = 60%) with only two biological predictors: tree circumference at death time and wood specific density. Neither selective logging nor local topography had a differential effect on wood decay rates. Including the mode of death into the model revealed that standing dead trees decomposed faster than downed dead trees, but the gain of model accuracy remains rather marginal. Overall, these results suggest that the release of carbon from tropical dead trees to the atmosphere can be simply estimated using tree circumference at death time and wood density.     

Melding ecology,classical weed biocontrol,and plant microbial ecology can inform improved practices in controlling invasive plant species

Early research leading to the successful biological control of invasive species such as Opuntia spp., and Hypericum perforatum set examples and provided data useful for research programs that would follow. However, this early work failed to become established as a source of applicable principles for later workers in weed biocontrol. Recently, retrospective and parallel studies have been suggested as a means to reengage with earlier work to derive useful ideas and data to enhance future programs in weed biocontrol. Parallel studies by workers in plant community ecology on the nature of feedback elicited by plant species in their invaded and native range have shown the importance of soil microbial communities in effecting feedback. Retrospective reexamination of previous studies would likely provide clues to other insect–plant pathogen interactions in addition to those described by the author and others. The effects of invasive species in profoundly altering soil microbial communities point to the need for further studies on key microbial species contributing to or driving the impact of biocontrol. These collective data suggest that the desired goal of selecting for and utilizing stronger biocontrol agents to reduce nontarget effects and to increase the impact of biological control programs would be best served by prerelease studies that assess the propensity of a candidate agent for direct or indirect interaction with other agents. This could be assessed through the use of survival analysis. Overall, parallel empirical and retrospective studies should be a necessary part of how biological control is practiced.     

Screening of antagonistic yeast strains for postharvest control of Penicillium expansum causing blue mold decay in table grape

Blue mold decay caused by Penicillium expansum is one of the most important postharvest diseases of grapes, leading to considerable economic losses. Regarding the increasing demand for pesticide-free foods, this study aimed to find potential yeast strains for biological control of blue mold on table grapes. A total of 50 yeast strains were screened for antagonistic activity against P. expansum using the dual culture method and six strains significantly inhibited the fungal growth. All six yeast strains (Coniochaeta euphorbiae, Auerobasidium mangrovei, Tranzscheliella sp., Geotrichum candidum, Basidioascus persicus, and Cryptococcus podzolicus) reduced the fungal growth (29.6–85.0%) and the decay degree of wounded grape berries inoculated with P. expansum while G. candidum was found to be the most efficient biocontrol agent. On the basis of antagonistic activity, the strains were further characterized by in vitro assays involving inhibition of conidial germination, production of volatile compounds, iron competition, production of hydrolytic enzymes, biofilm-forming capacity, and exhibited three or more putative mechanisms. To our knowledge, the yeasts are reported for the first time as potential biocontrol agents against the blue mold of grapes but more study is required to evaluate their efficiency related to field application.