Mediterranean Plants as Potential Source of Biopesticides: An Overview of Current Research and Future Trends.

The development and implementation of safe natural alternatives to synthetic pesticides are urgent needs that will provide ecological solutions for the control of plant diseases, bacteria, viruses, nematodes, pests, and weeds to ensure the economic stability of farmers and food security, as well as protection of the environment and human health. Unambiguously, production of botanical pesticides will allow for the sustainable and efficient use of natural resources and finally decrease the use of chemical inputs and burden. This is further underlined by the strict regulations on pesticide residues in agricultural products and is in harmony with the Farm to Fork strategy, which aims to reduce pesticide use by 50% by 2030. Thus, the present work aims to compile the scientific knowledge of the last 5 years (2017-February 2023) regarding the Mediterranean plants that present biopesticidal effects. The literature review revealed 40 families of Mediterranean plants with at least one species that have been investigated as potential biopesticides. However, only six families had the highest number of species, and they were reviewed comprehensively in this study. Following a systematic approach, the extraction methods, chemical composition, biopesticidal activity, and commonly used assays for evaluating the antimicrobial, pesticidal, repellant, and herbicidal activity of plant extracts, as well as the toxicological and safety aspects of biopesticide formulation, are discussed in detail. Finally, the aspects that have not yet been investigated or are under-investigated and future perspectives are highlighted.

Herbicide Use in the Era of Farm to Fork: Strengths, Weaknesses, and Future Implications.

Climate change mitigation is a major concern of the European Union (EU). In 2019, the EU presented the European Green Deal (EGD), a new environmental strategy that aimed to neutralize climate change by 2050. Within its policy areas, the EGD included the Farm to Fork (F2F) Strategy that aims to reduce pesticide use by 50%, by 2030. This reduction was proposed due to the supposed negative effects of pesticides on the environment and its biota. Among the different pesticide groups (herbicides, fungicides, insecticides, etc.) though, herbicides are perhaps the hardest to reduce. This review aimed to shed light to any factors that might hinder the reduction of herbicide use; thus, the implementation of the Farm to Fork Strategy underlines some of its weaknesses and highlights key points of a viable herbicide reduction-related policy framework. The literature suggests that integrated weed management (IWM) consists perhaps the most suitable approach for the reduction of herbicides in the EU. Even though it is too soon to conclusively assess F2F, its success is not impossible.

Effect of land-use types on edaphic properties and plant species diversity in Mediterranean agroecosystem.

Land-use intensification, contrary to sustainable land management, has an impact on the healthiness of the environmental agroecosystem. To assess the environmental implications in abandoned land, olive groves and maize crops, the most sensitive and reliable edaphic indicators were measured to estimate plant species diversity and potentially toxic elements in soil, among different types of land-use. Species diversity presents a decrease in maize crops and olive groves compared to abandoned land. The families with the greatest species diversity were Poaceae, Asteraceae and Fabaceae in each land-use. From the results of the canonical correspondence analysis among species, sampling sites and selected environmental variables, a clear separation between species and sampling sites belonging to different types of land-use was found, presenting strong correlation with specific edaphic parameters (pH, Soil Organic Matter, Silt, Electrical Conductivity, Total Nitrogen, N O 3 - , P, K, Zn and Cu). Species diversity was reduced in maize crops due to anthropogenic interventions such as the excessive use of nitrogen and phosphate fertilizers and herbicides. Despite the fact that the lowest richness of plant species was found in olive groves, non-removal of crop residue preserves soil organic matter. In 7.4% of soil samples in olive groves, Cu total concentrations were over 100 mg kg-1 denoting polluted soils, while the potentially toxic concentrations of bioavailable copper fraction ( Cu DTPA ) probably lead to a decrease of species diversity. Future researches should therefore focus on the accumulation of toxic elements in agricultural land to preserve species diversity and a healthy environment.

Ternary [Al(2)O(3)-electrolyte-Cu(2+)] species: EPR spectroscopy and surface complexation modeling.

Cu(2+) binding on gamma-Al(2)O(3) is modulated by common electrolyte ions such as Mg(2+), SO(4)(2-), and PO(4)(3-) in a complex manner: (a) At high concentrations of electrolyte ions, Cu(2+) uptake by gamma-Al(2)O(3) is inhibited. This is partially due to bulk ionic strength effects and, mostly, due to direct competition between Mg(2+) and Cu(2+) ions for the SO(-) surface sites of gamma-Al(2)O(3). (b) At low concentrations of electrolyte ions, Cu(2+) uptake by gamma-Al(2)O(3) can be enhanced. This is due to synergistic coadsorption of Cu(2+) and electrolyte anions, SO(4)(2-) and PO(4)(3-)(.) This results in the formation of ternary surface species (SOH(2)SO(4)Cu)(+), (SOH(2)PO(4)Cu), and (SOH(2)HPO(4)Cu)(+) which enhance Cu(2+) uptake at pH<6. The effect of phosphate ions may be particularly strong resulting in a 100% Cu uptake by the oxide surface. (c) EPR spectroscopy shows that at pH<>pH(PZC) Cu(2+) may coordinate to two SO(-) groups. At pH<

Electrolyte ion effects on Cd2+ binding at Al2O3 surface: specific synergism versus bulk effects.

Cd(2+) binding on gamma-Al(2)O(3) was studied in the presence of the common electrolyte ions Mg(2+), SO(4)(2-), and NO(3)(-) at high and low concentrations. Direct measurements were performed for Cd(2+) as well as for electrolyte ion adsorption as a function of pH. The experimental data reveal that Cd(2+) binding on gamma-Al(2)O(3) is modulated by the electrolyte ions in a complex manner. At high electrolyte concentration, Cd(2+) uptake by gamma-Al(2)O(3) is inhibited. Theoretical analysis by a surface complexation model shows that this effect can be attributed partially to bulk, ionic strength, and effect of the electrolyte, but the most significant inhibition is due to direct competition between Mg(2+) and Cd(2+) ions for the [triple bond]SO(-) surface sites of gamma-Al(2)O(3). At low concentration of electrolyte ions, Cd(2+) uptake by gamma-Al(2)O(3) can be enhanced due to synergistic co-adsorption of Cd(2+) and electrolyte anions, particularly SO(4)(2-) and to a lesser extent NO(3)(-). The theoretical analysis shows that this co-adsorption is due to formation of ternary surface species ([triple bond]SOH(2)SO(4)Cd) and ([triple bond]SOH(2)NO(3)Cd) which enhance Cd-uptake at pH values well below the point of zero charge of the gamma-Al(2)O(3).