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Abstract Aims Incorporating biofertilizers, such as arbuscular mycorrhizal fungal (AM) fungal inoculants, into vineyard management practices may enhance vine growth and reduce environmental impact. Here, we evaluate the effects of commercially available and local AM fungal inoculants on the growth, root colonization, and nutrient uptake of wine grapes (Vitis vinifera) when planted in a field soil substrate. Methods and results In a greenhouse experiment, young wine grapes were planted in a field soil substrate and inoculated with one of three commercially available mycorrhizal inoculant products, or one of two locally collected whole soil inoculants. After 4 months of growth, inoculated vines showed no differences in plant biomass, colonization of roots by AM fungi, or foliar macronutrient concentrations compared to uninoculated field soil substrate. However, vines grown with local inoculants had greater shoot biomass than vines grown with mycorrhizal inoculant products. Conclusions Although effects from inoculations with AM fungi varied by inoculant type and source, inoculations may not improve young vine performance in field soils with a resident microbial community.

Abstract Aims The aim of this work was to evaluate the efficacy of an organosilicon-based, commercially available antimicrobial formulation in the My-shield® product line against bacterial surface contamination. Methods and results The antimicrobial product was tested in vitro for its long-term persistence on surfaces and effectiveness against Staphylococcus aureus biofilms in comparison to 70% ethanol and 0.1% or 0.6% sodium hypochlorite. Field testing was also conducted over 6 weeks at a university athletic facility. In vitro studies demonstrated the log reductions achieved by the test product, 70% ethanol, and 0.1% sodium hypochlorite were 3.6, 3.1, and 3.2, respectively. The test product persisted on surfaces after washing and scrubbing, and pre-treatment with this product prevented S. aureus surface colonization for up to 30 days. In comparison, pre-treatment with 70% ethanol or 0.6% sodium hypochlorite was not protective against S. aureus biofilm formation after seven days. The field test demonstrated that weekly applications of the test product were more effective at reducing surface bacterial load than daily applications of a control product. Conclusions The test product conferred greater long-term protection against bacterial growth and biofilm formation by S. aureus than ethanol and sodium hypochlorite. Even with less frequent applications, the test product maintained a high level of antimicrobial activity.

Abstract Aims The effects of a tropical forest logging road on soil C and N, and the compositions of Actinobacteria, Acidobacteria, and wood rot/lignin-degrading fungal (WRT/LD) decomposer communities were evaluated. Methods and results Soils from a healthy Costa Rican old growth forest before Hurricane Otto and from an adjacent, recently formed logging road built after Hurricane Otto were collected over 4 years and assessed for C and N metrics, and characteristics of the three decomposer communities determined by Illumina amplicon sequencing methods. The Logging Road negatively impacted the soil total organic C, respiration, biomass C, qCO2, and total N, while the Actinobacterial and Acidobacterial communities changed from stable compositions of copiotrophic taxa in the rich forest soil to stable compositions of oligotrophic taxa in the poor logging road soil, and the WRT/LD community changed from stable compositions of copiotrophic taxa in the forest soils to an unstable community of oligotrophic taxa with almost no overlap in genera between logging road soils. Conclusions The logging road negatively influenced 3 decomposer communities and associated C and N metrics, with the two bacterial communities taxonomically stabilizing, but the fungal community taxonomically diverging into an unstable composition over time. Monitoring efforts are on-going to provide local forest land managers with potential indicators of soil ecosystem damage and recovery.