The European Union is promoting regulatory changes to ban fungicides because of the impact their use has on the ecosystem and the adverse effects they can pose for humans. An ecofriendly alternative to these chemicals to fight against fungal species with low toxicity is essential oils and their compounds extracted from aromatic plants. The purpose of this study was to evaluate the in vitro antifungal capacity of the botanical compounds eugenol, carvacrol, thymol, and cinnamaldehyde, and the synergy or antagonism of their mixtures, against Botryotinia fuckeliana and Rhizoctonia solani. Different bioassays were performed at doses of 300, 200, 150, and 100 µg/mL using pure commercial compounds and their combination in potato dextrose agar culture medium. Growth rate and the mycelium growth inhibition parameters were calculated. Phenolic compounds and their combination inhibited the development of species at the different concentrations, with fungicidal or fungistatic activity shown under almost all the tested conditions. When comparing the growth rates of the species in the control plates and treatments, the statistical analysis showed that there were statistically significant differences. The mixture of compounds improved fungicidal activity against the studied species and at a lower concentration of monoterpenes.

Melon is a global crop with a value of USD 31 billion. However, up to 30% of yield is lost due to phytopathogens. Essential oils are a sustainable approach to crop protection and storage, enhancing food security and reducing agricultural losses. We evaluated the antifungal potential of clove essential oil and pure eugenol against Alternaria alternata, Curvularia hawaiiensis, Fusarium oxysporum f. sp. lycopersici (FOL), Fusarium solani f. sp. cucurbitae (FSC), Rhizoctonia solani, and Verticillium dahliae in vitro. We also evaluated the resistance of melons, including eugenol-poor Cucumis melo cv. vedrantais (CMV) and eugenol-rich C. melo cv. makuwa (CMM), to infection caused by FOL and FSC. Chemical analysis of clove oil reveals that eugenol was the main compound, at 89.28%. Clove oil and eugenol at 300 μg/mL reduced the growth of all fungal species. Pure eugenol exhibited the strongest antifungal activity, with 95–100% growth inhibition. Eugenol-rich melons did not show necrosis or internal rot when inoculated with FSC, and had minimal lesions, while eugenol-poor melons revealed more advanced rot symptoms. Clove oil and eugenol are antifungal alternatives that may improve food safety. These findings demonstrate the high potential of eugenol to reduce postharvest losses in melon and contribute to future breeding programmes aimed at developing contamination-resistant cultivars.

Arundo donax is a plant native to Asia and is considered an invader species in the Mediterranean region and many tropical zones in the world. These invader plants can be collected to produce a biomass, which can be converted to ash by combustion. The scope of the study is to assess the use of these ashes (Arundo donax straw ash [ADSA]) as supplementary cementing material due to their relatively high silica content. Electron microscopy studies on dried and calcined samples of different plant parts (cane, sheath leaf and leaf) were carried out. Some different cellular structures were identified in the spodogram (remaining skeleton after calcination). Major silica content was found in leaves and sheath leaves. The main element in all the ashes studied, together with oxygen, was potassium (22 to 46% depending on the part of the plant). Chloride content was also high (5–13%), which limits their use to non-steel reinforced concrete. The pozzolanic reactivity of ADSA was assessed in pastes by thermogravimetric analysis and in mortars with ordinary Portland cement based on compressive strength development. Excellent results were found in terms of reactivity.

Soil stabilization using cementing materials is a well-known procedure for earth-based building blocks preparation. For the selected binding materials, innovation usually focuses on low carbon systems, many of which are based on alkaline activation. In the present paper, blast furnace slag (BFS) is used as a mineral precursor, and the innovative alkali activator was olive stone biomass ash (OBA). This means that the most important component in CO₂ emissions terms, which is the alkali activator, has been replaced with a greener alternative: OBA. The OBA/BFS mixture was used to prepare compacted dolomitic soil blocks. These specimens were mechanically characterized by compression, and water strength coefficient and water absorption were assessed. The microstructure of blocks and the formation of cementing hydrates were analyzed by field emission scanning electron microscopy and thermogravimetry, respectively. The final compressive strength of the 120-day cured blocks was 27.8 MPa. It was concluded that OBA is a sustainable alkali activator alternative for producing BFS-stabilized soil-compacted blocks: CO₂ emissions were 3.3 kgCO₂/ton of stabilized soil, which is 96% less than that for ordinary Portland cement (OPC) stabilization.