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One of the main effects of applying biostimulants to grapevines is an increase in berry phenolic compound content. In the current study, grapes treated at veraison with abscisic acid (ABA), benzothiadiazole (BTH) and chitosan (CHT) were vinified. Treated grapes, compared to untreated grapes (the control), resulted in wines with a significantly higher concentration of anthocyanins and phenolic content. Furthermore, in a descriptive sensory analysis, wines made from treated grapes were found to have significantly more intense fruity notes and aroma and better overall mouthfeel quality.

This work investigates the effects of an organic fertilizer enriched in Ca and Mg and two bacterial inoculants, applied alone and in combination, on soil fertility, plant growth, nutrition, and production of secondary metabolites, namely, acemannan and total phenolic compounds (TPCs), by Aloe vera (Aloe barbadensis Miller), under field cultivation. The first inoculum consisted of five native bacterial strains (Pseudomonas sp., Enterobacter sp., and three strains of Pantoea sp.), characterized in vitro as putative plant growth promoters, isolated from local organic farming fields of Aloe vera. The second inoculant was a commercial product (BACTILIS-S and HUMOFERT) and consisted of three Bacillus species: B. pumilus, B. amyloliquefaciens, and B. subtilis. The organic fertilizer (HUMO-CAL M-8O) was a mixture of humic and fulvic acids, with an additional CaCO3 (40% w/w) and MgO (4% w/w). The most significant increase in the content of acemannan and TPCs was detected under single application of the organic fertilizer, which was linked to enhanced concentration of Mg and Ca in the leaf gel. The concentration of acemannan tended to be increased with the combined application of the organic fertilizer and microbial inoculants. TPCs were significantly increased in both single and combined treatments, seemingly related to Fe concentration in the leaf rinds.

Nitrogen nutrition is one of the most effective cultural practices in vineyards. The vine nitrogen status influences the berries’ quality characteristics and the produced wines. The current study investigated the effect of traditional nitrogen fertilization in the form of ammonium sulfate compared to nitrogen fertilization coupled with the nitrification inhibitor 3,4-Dimethylpyrazole phosphate (DMPP) on the agronomic characteristics of grapes and the produced wines of the white variety Savvatiano from a productive vineyard in the Attiki region. Must and wine quality was evaluated by a chemical analysis and sensorial evaluation by trained panelists. The different forms of nitrogen fertilizers did not significantly affect the aroma and sensory profile in contrast to unfertilized grapevines. In addition, the applied fertilization increased some important aroma compounds in the wine, compared to no fertilization. The significance of this work is to add information about the effect of nitrogen fertilization on the wine volatile composition of the Greek white grapevine Savvatiano.

Plants establish symbiotic relationships with soil bacteria or fungi, which colonize the plant root and provide the plant with inorganic nutrients, in exchange for photosynthesis products. Legume plants associate with both arbuscular mycorrhizal fungi (AMF) and the nitrogen-fixing soil bacteria called rhizobia. During the legume-rhizobium symbiosis, biological nitrogen fixation takes place in specific plants organs formed on the root, called nodules. Using the model legume Lotus japonicus, we studied the establishment of the legume-rhizobia-AMF tripartite symbiosis. We examined how the AM fungus Rhizophagus irregularis and the rhizobium Mesorhizobium loti affected one another during the colonization of the same legume roots, by performing co-inoculations. Moreover, we monitored the effect of the co-inoculation on the general plant performance. According to our results, the presence of M. loti had no effect on the root colonization by R. irregularis. However, root colonization by R. irregularis had a positive effect on the formation of root nodules. This study aims to enhance our understanding on how the plant selects, combines and controls its symbionts, towards to a more efficient use of legume plants in agroecosystems.

This work investigates the effect of plant species (Eucalyptus camaldulensis vs. Arundo donax) on carbon (C) turnover during wastewater application to the land. The study was carried out in 40-liter pots under field conditions and plant species were treated either with pre-treated municipal wastewater or freshwater. Plant species had a strong effect on soil organic matter with pots planted with E. camaldulensis showing greater values than pots planted with A. donax. In accordance, greater respiration rates were measured in E. camaldulensis pots compared to those planted with A. donax. The respiration rate followed a decreasing trend with the progress of the season for both species. These findings suggest differences in soil microbial community composition and/or activity in the rhizosphere of plant species. Minor effects of plant species or effluent were observed in dissolved organic carbon, protein, and hexoses content. In conclusion, the results of the present study reveal an important role of plant species on C cycling in terrestrial environments with potential implications on the sequestration of C and release of nutrients and pollutants.