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In recent years, a new phenomenon of early olive drop is causing production losses in olive groves throughout northern Italy. To analyze the possible causes, field and laboratory trials were performed to assess the involvement of fungal pathogens and insect pests in this disease. External and internal symptoms of fungal infections or insect-feeding activities were researched. Fungi present in healthy and dislodged olives were investigated. The relationship between olives that fell and Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) infestation was assessed in a controlled infestation trial, and the effectiveness of an insecticidal strategy in reducing early olive drop was tested in open field conditions. A comparable number of fungi, mostly endophytes, were isolated and identified from both healthy and dislodged olives. The damage observed on dislodged olives was primarily ascribed to pentatomids feeding activity. Six stink bugs species were found in olive canopies, that is, the invasive H. halys, which was by far the most abundant, and Acrosternum heegeri Fieber, Nezara viridula (Linnaeus), Palomena prasina (Linnaeus), Piezodorus lituratus (Fabricious), and Rhaphigaster nebulosa (Poda). Halyomorpha halys caused intense fruit drop in the controlled infestation trial, and its infestation level significantly correlated with the number of olives that fell. Native stink bugs, present in much lower population compared to H. halys, could also partially contribute to early drop of olives. Insect proof net significantly reduced the early olive drop disease, while insecticide applications only partially reduced the stink bugs population density and, proportionally, early olive drop., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America.)

Plant diseases caused by Pseudomonas syringae are essentially controlled in the field with the use of copper-based products and antibiotics, raising environmental and safety concerns. Antimicrobial peptides (AMPs) derived from fungi may represent a sustainable alternative to those chemicals. Trichogin GA IV, a non-ribosomal, 11-residue long AMP naturally produced by the fungus Trichoderma longibrachiatum has the ability to insert into phospholipidic membranes and form water-filled pores, thereby perturbing membrane integrity and permeability. In previous studies, peptide analogs modified at the level of specific residues were designed to be water-soluble and active against plant pathogens. Here, we studied the role of glycine-to-lysine substitutions and of the presence of a C-terminal leucine amide on bioactivity against Pseudomonas syringae bacteria. P. syringae diseases affect a wide range of crops worldwide, including tomato and kiwifruit. Our results show that trichogin GA IV analogs containing two or three Gly-to-Lys substitutions are highly effective in vitro against P. syringae pv. tomato (Pst), displaying minimal inhibitory and minimal bactericidal concentrations in the low micromolar range. The same analogs are also able to inhibit in vitro the kiwifruit pathogen P. syringae pv. actinidiae (Psa) biovar 3. When sprayed on tomato plants 24 h before Pst inoculation, only tri-lysine containing analogs were able to significantly reduce bacterial titers and symptom development in infected plants. Our results point to a positive correlation between the number of lysine substitutions and the antibacterial activity. This correlation was supported by microscopy analyses performed with mono-, di- and tri-Lys containing analogs that showed a different degree of interaction with Pst cells and ultrastructural changes that culminated in cell lysis., Competing Interests: Declaration of competing interest The authors declare the absence of any conflict of interest., (Copyright © 2023. Published by Elsevier Inc.)

Botrytis cinerea is a well-known plant pathogen responsible for grey mould disease infecting more than 500 plant species. It is listed as the second most important plant pathogen scientifically and economically. Its impact is particularly severe in grapes since it affects both the yield of grape berries and the quality of wines. While various methods for detecting B. cinerea have been investigated, the application of Oxford Nanopore Technology (ONT) for complete ribosomal operon sequencing, which has proven effective in human and animal fungal research and diagnostics, has not yet been explored in grapevine ( Vitis vinifera ) disease research. In this study, we sequenced complete ribosomal operons (∼5.5 kb amplicons), which encompass the 18S, ITS1, 5.8S, ITS2, and 28S regions, from both pure cultures of B. cinerea and infected grapevine leaf samples. Minimap2, a sequence alignment tool integrated into the EPI2ME software, served as a taxonomy classifier, utilizing the custom reference database FRODO. The results demonstrate that B. cinerea was detectable when this pathogen was not the dominant fungal species in leaf samples. Additionally, the method facilitates host DNA-free sequencing and might have a good potential to distinguish other pathogenic and non-pathogenic fungal species hosted within grapevine's infected leaves, such as Alternaria alternata, Saccharomyces cerevisiae, Saccharomyces boulardii, Mucor racemosus, and Ascochyta rabie. The sequences were uploaded to the NCBI database. Long amplicon sequencing method has the capacity to be broadened to other susceptible crops and pathogens, as a valuable tool for early grey rot detection and mycobiome research. Future large-scale studies are needed to overcome challenges, such as comprehensive reference databases for complete fungal ribosomal operons for grape mycobiome studies., (© The Author(s) 2024. Published by Oxford University Press.)