Beneficial microorganisms promote plant growth through different mechanisms, such as the production of plant hormones, the synthesis of 1-aminocyclopropane-1-carboxylic acid deaminase (ACCD), or, through volatile organic compounds (VOCs) emission. There are numerous studies describing a biostimulant action mediated by VOCs released by bacteria and filamentous fungi. However, in soil yeasts, research in this regard is still incipient. In a previous study, we present the stimulatory action of Solicoccozyma aeria YCPUC79 on tomato seedling growth by inoculating the rootzone with this yeast. The positive effect of S. aeria was related to the synthesis of indole acetic acid (IAA) and the presence of ACCD activity by the yeast. In the present study, we evaluated whether S. aeria is capable of emitting VOCs with biostimulant activity. For this, an experiment was conducted to test the release of VOCs in four treatments: S. aeria (Sa), tomato seedlings (T), tomato seedlings sharing the ambient with S. aeria but with no physical contact (TSa) plus a control with no yeast nor tomato seedlings (C). Tomato seedlings exposed to S. aeria in-oculum (TSa) presented 1.2-fold shorter main roots but increased the number of lateral roots by 80% compared to T. Regarding the analysis of VOCs, 59 compounds were identified excluding those found in the control treatment. These compounds represent twelve chemical families, in-cluding alcohols, esters, furans, hydrocarbons, ketones and terpenes. The treatment TSa shows an increased abundance of ketones, alcohols, esters, sulfur-containing compounds, and pyrazines in comparison to T treatment. Three compounds (butyl hept-4-yl ester-phthalic acid, (E)1.3-pentadiene and 1-propenylthiol) were exclusively present in the TSa treatment. This study provides, for the first time, information on a soil yeast capable of promoting the production of lateral roots in tomato through VOCs.

Sugarcane plays a crucial role in global sugar and ethanol production. Conventionally, sugar-cane propagation involves planting billets. However, Brazilian researchers have introduced the innovative pre-sprouted seedlings (PSS) method, widely used in the MEIOSI (Simultaneously Occurring Interrotational Method) system. Although MPB has several advantages over the con-ventional method, its sensitivity to water scarcity is a challenge. The study aimed to evaluate the survival and growth of PSS inoculated with Bacillus licheniformis and Bacillus subtilis under differ-ent water regimes. The experiment was conducted in the field in a randomized block in strips (split-block) using a 2×4 factorial scheme consisting of two inoculation conditions (with and without bacteria) and four water regimes (0%, 33%, 66%, and 100% of the ideal irrigation). The bacteria increased the PSS's survival and water use efficiency in the field. In addition, inocula-tion increased root and shoot growth, as well as the nutrient uptake such as N, P, Mn, Zn, and Cu, which resulted in a higher number of stalks per meter and, therefore, a higher multiplica-tion rate in the MEIOSI system. Inoculation proved to be a promising alternative for establishing PSS under water restriction.

In recent days, the adverse effect of climate change on soil properties in the agriculture sector is a dreadful reality worldwide. Climate change-induced abiotic stresses such as salinity, drought and temperature fluctuations are devastating the crops’ physiological responses, productivity and overall yield which is ultimately posing a serious threat to global food security and agroecosystems. The applications of chemical fertilizers and pesticides contribute towards further deterioration and rapid change in climate. Therefore, more careful, eco-friendly and sustainable strategies are required to mitigate the impact of climate-induced damage on agriculture sector. This paper reviews the recently reported damaging impacts of abiotic stresses on various crops along with two emerging mitigation strategies; biochar and biostimulants, in light of recent studies for combating the worsening impact of deteriorated environment and climate change on crops physiological responses, yields, soil properties, and environment. Here we highlighted the impact of climate change on agriculture and soil properties along with recently emerging mitigation strategies applying biochar and biostimulants, towards protecting the soil, agriculture and environment.

Common bean (Phaseolus vulgaris L.) is an important crop for food security and for national economics for several countries worlwide. One of the most important factors of risk in common bean production is the fungal disease anthracnose caused by Colletotrichum lindemuthianum, which in some cases, causes complete yield losses; this kind of plant disease is usually managed through the application of chemical products such as fungicides, that are commonly not accepted by society, this rejection is based on the relationship of pesticides with health damage and environmental contamination. In order to help in solving this drawbacks, the present work propose the use of Electrochemically Activated Salt Solutions(EASS) as a safer pathogen control agent in crops due to it have shown an elicitor and biostimulant effect on plants such as tobacco and apple. With this background, this manuscript presented in vitro results of the evaluation of the inhibitory effect for multiple bean pathogens and in vivo results of EASS in the common bean-Colletotrichum pathosystem by in vitro evaluations of the inhibitory effect for multiple bean pathogens and in vivo evaluation of the infection severity and defense activation such as secondary metabolites production and antioxidant activity. EASS presence in growth media had strong inhibitory effect, at beginning of experiment, for some of the evaluated fungi. EASS showed effect against the development of the disease when applied in specific doses to prevent distress in plants.

The use of biostimulants consisting of plant growth promoting rhizobacteria (PGPR) is rapidly expanding in horticulture in recent years. In the current study, a novel mix of six Bacillus sp. strains was tested as a PGPR biostimulant in two experiments with zucchini squash (Cucurbita pepo L.) cultivated in the greenhouse soil and in an open field, respectively. In both experiments, seeds of the local landrace ‘Kompokolokytho’ and the commercial hybrid ‘ARO-800’ were either inoculated or non-inoculated with the PGPR biostimulant. The application of the six Bacillus sp. strains increased both the vegetative growth and the yield of zucchini squash, and these effects were associated with significantly higher shoot phosphorus levels in both experiments and both genotypes. Furthermore, at the end of the cultivation, the colony forming units of Bacillus sp. were appreciably higher in plants originating from inoculated compared to non-inoculated seeds, indicating that the tested mix of Bacillus sp can be successfully applied through seed inoculation. ‘ARO-800’ produced more vegetative and fruit biomass than ‘kompokolokytho’ under greenhouse cropping conditions, while in the open-field crop both genotypes performed equally, presumably because the local landrace is traditionally grown in open fields, and thus it is not well adapted to greenhouse cropping.

In order to ensure food security worldwide in the face of current climatic changes, a higher quality and quantity of crops is necessary to sustain the growing human population. By developing a sustainable circular economy and biorefinery approaches, we can move from a petroleum-based to a bio-based economy. Plant biostimulants have long been considered an important source of plant growth stimulants in agronomy and agro-industries with both macroalgae (seaweeds) and microalgae (microalgae). There has been extensive exploration of macroalgae biostimulants. A lack of research and high production costs have constrained the commercial implementation of microalgal biostimulants, despite their positive impact on crop growth, development and yields. The current knowledge on potential biostimulatory compounds, key sources and their quantitative information from algae is summarized in the present review. Our goal is to provide a brief overview of the potential for microalgal biostimulants to improve crop production and quality. A number of key aspects are discussed, including the biostimulant effects caused by microalgae extracts, as well as the feasibility and potential for cocultures and coapplication with other biostimulants and biofertilizers. This article also discusses the current knowledge, recent developments and achievements in extraction techniques, types of applications, timings of applications. Ultimately, this review highlights the potential for microalgal biostimulants for sustainable agricultural practices, the algal biochemical components contributing to these traits, and finally bottlenecks and involved prospects in commercializing microalgal biostimulants.

Microbial-based biostimulants containing arbuscular mycorrhizal fungi (AMF), Trichoderma fungi and plant growth-promoting rhizobacteria (PGPR) have been applied in an open-field tomato cultivation. A two-years field experiment (2020-2021) was performed in Southern Italy on “Heinz 1534” processing tomato hybrid, using three commercial formulations characterized by different microbial consortia (MIC: Glomus spp., Rhizophagus spp., Bacillus spp., Streptomyces spp., Pichia spp., Trichoderma spp.; EKO: Glomus spp., Bacillus spp., Streptomyces spp., Pseudomonas spp., Arthrobotrys spp., Monacrosporium spp., Paecilomyces spp., Myrothecium spp., Trichoderma spp.; FID: Glomus spp., Bacillus spp., Trichoderma spp.) and comparing them to untreated control (CTRL). The effect of growing season and microorganism-based treatments on yield, technological traits and functional quality of tomato fruits was assessed. The year of cultivation (Y) affected yield (with lower fruit weight, higher marketable to total yield ratio and higher % of total defected fruits in 2020), and technological components (higher dry matter, total acidity, total soluble solids in 2020). During the first year of the trial, all evaluated treatments (MIC, EKO and FID) enhanced soluble solids content by 10%, on average, compared to CTRL. Sucrose and lycopene contents were influenced both by the microbial-based treatments and the growing season (greater values found in 2021 with respect to the first year). Y factor also significantly affected all evaluated metabolites contents, except for tyrosine, essential (EAA) and branched-chain (BCAAs) amino acids. Over two years of field trial, FID biostimulant enhanced the contents of proteins (+53.71%), alanine (+16.55%), aspartic acid (+31.13%), γ-aminobutyric acid (+76.51%), glutamine (+55.17%), glycine (+28.13%), monoethano-lamine (+19.57%), total amino acids (+33.55), essential amino acids (+32.56%) and branched-chain amino acids (+45.10%) compared to the untreated control. Our findings highlighted the valuable effect of FID microbial inoculant in boosting several primary metabolites (proteins and amino acids) in the fruits of processing tomato crop grown under Southern Italy environmental condi-tions, although no effect on yield and its components was appreciated.

Entomopathogenic fungi perform important functions in the ecosystem as natural antagonists of insects, which can be used in agriculture. Interestingly, recent studies showed a significant promotion of tested plants growth in the presence of fungi. We hypothesize that some of various compounds produced by entomopathogenic fungi can positively affect plant development. To test this hypothesis, fungal extracts of entomopathogenic fungus Beauveria bassiana were prepared at different conditions of temperature and pH. In addition to determination of the ammonium nitrogen content, the composition of extracts was analyzed by elemental ICP-OES. Then, their effect on the wheat germ growth was studied using various extract concentrations. After experiments, tested plants were measured, weighed, and the chlorophyll content was determined. Finally, the impact of extracts on the selected G+ and G- bacteria growth was examined to exclude the possibility of interference with soil microorganisms. The highest length of the wheat shoot was obtained for the use of 10-times diluted extract (10%) at pH 10 obtained at 20°C. In contrast, addition of 10% extract (pH 10) obtained at 75°C resulted in the shortest shoot. Generally, the extracts obtained at 75°C showed phytotoxic properties leading to lower values of shoot length and fresh weight in comparison to the control group. Our preliminary results are the first confirming the potential of fungal water extracts as factors promoting plant growth. Further detailed study should be carried out to confirm the effects in real environment conditions. Also, the consistency of the plant growth stimulation across different entomopathogenic fungi, and agriculturally used plant species should be tested.

The Douro Demarcated Region (DDR) has peculiar edaphoclimatic characteristics that provide a suitable terroir for premium wine production. As climate change effects continue to emerge, ensuring productivity and quality becomes increasingly important for viticulturists, as those directly determine their profits. Cultural approaches, such as the use of biostimulants, are actively being developed to mitigate abiotic stress. The main objective of this work was to assess the effect of foliar sprays of a seaweed (Ascophyllum nodosum) based extract (ANE) and glycine betaine (GB) on grape berry quality, bioactive compounds, and antioxidant activity. A trial was installed in a commercial vineyard (cv. Touriga Franca) in the Douro Superior (Upper Douro) sub-region of the Douro Demarcated Region. In 2020, a total of three foliar sprayings were performed during the growing season, namely at pea-size, bunch closure, and veraison. There was a positive effect of both biostimulants (ANE and GB) on the physiological and biochemical performance of cv. Touriga Franca exposed to summer stress. In general, the GB 0.2% spraying was the most promising treatment for this grape cultivar, as it increased berry quality, the concentration of bioactive compounds (total phenolics, flavonoids and ortho-diphenols), and the antioxidant activities. These results revealed the efficacy of biostimulants sprayings as sustainable viticultural practice, improving berry quality under summer stress conditions.

Keywords: Trichoderma sp., biogenic selenium nanoparticles, capping biomolecules, bio-corona, agriculture, plant biostimulants, phytopathogens, physicochemical properties, bioactivity mechanism