Bacterial soft rot, caused by Pectobacterium carotovorum subsp. carotovorum (Pcc), is a major threat to potato production, leading to severe yield losses and postharvest decay. This study evaluated the efficacy of chitosan, a biodegradable and ecofriendly biopolymer, as an alternative to chemical fungicides for controlling soft rot. Seven Pcc isolates were obtained from naturally infected potato tubers in Assiut Governorate and their pathogenicity was confirmed. Chitosan at concentrations of 1–7 mg/ml and azoxystrobin plus difenoconazole (Dicore) at 2,000–10,000 ppm was tested both in vitro and in vivo. Chitosan completely inhibited bacterial growth at ≥4 mg/ml. In vivo, 24-hour immersion in chitosan or Dicore (10,000 ppm) reduced disease severity to 15.5%, while shorter exposure times resulted in higher infection rates. Under greenhouse conditions, disease severity decreased to 4–5.3% with chitosan or Dicore at 10,000 ppm, compared to 100% in untreated controls. These findings indicate that chitosan is a sustainable and eco-friendly alternative to chemical fungicides for managing bacterial soft rot in potatoes, reducing environmental risks while maintaining effective disease control.

Halfa grass (Desmostachya bipinnata) is an abundant lignocellulosic biomass with potential for thermochemical conversion and biochar production. This study investigated its physicochemical characteristics, pyrolysis kinetics, reaction mechanism, and thermodynamic behavior using an integrated experimental approach. Elemental analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to characterize the biomass and the derived biochar. Thermogravimetric analysis (TGA) was conducted under a nitrogen atmosphere at heating rates of 10, 20, and 30°C min⁻¹. The TG–DTG profiles revealed a typical multi-stage decomposition pattern associated with the degradation of hemicellulose, cellulose, and lignin fractions. The activation energy was determined using Flynn–Wall–Ozawa (FWO), Friedman (FM), Kissinger, and Vyazovkin (VYZ) methods. The average activation energies obtained from the FWO, FM, VYZ, and Kissinger methods were 144.28, 151.09, 150.79, and 156.00 kJ mol⁻¹, respectively, demonstrating good agreement among the applied kinetic approaches. The variation of activation energy with conversion confirmed that halfa grass pyrolysis proceeds through multiple overlapping reactions rather than a single elementary process. Master plot analysis indicated that diffusion-related models provided the closest agreement with the experimental data over different conversion ranges, although additional validation would be required for definitive mechanistic confirmation. Thermodynamic analysis revealed positive enthalpy and Gibbs free energy values, indicating that the decomposition process is endothermic and requires continuous energy input. FTIR and XRD analyses demonstrated substantial structural transformation during pyrolysis, including the decomposition of oxygen-containing functionalities and the formation of condensed aromatic carbon structures within the resulting biochar. These results provide valuable insight into the thermal decomposition behavior of D. bipinnata and contribute to a better understanding of its physicochemical and kinetic characteristics for future thermochemical conversion and biomass valorization applications.

Background Mosquitoes pose a significant threat as vectors for numerous human and animal diseases, particularly in tropical and subtropical regions, including Egypt. Given the prevalence of mosquito-borne diseases and the documented high densities of Culex pipiens in Assiut Governorate, there is a critical need for environmentally friendly mosquito management strategies. This study aimed to identify the morphogenetic and determine the enzymatic potential of native fungal isolates associated with mosquitoes in Assiut Governorate. Results Eight distinct fungal species were successfully characterized based on their morphological traits and ITS rDNA sequence data. These species were identified as Alternaria tenuissima, Trichoderma hamatum, Purpureocillium lilacinum, Geotrichum candidum, and four Fusarium species (F. oxysporum, F. solani, F. equiseti, and F. incarnatum). The results of enzymatic screening emphasize that twenty-two fungal isolates belonging to eight species had the biochemical machinery substantial for cuticle degeneration, with various levels of phospholipase, lipase, protease, and chitinase activities. The strongest synergistic enzymatic profiles were notably displayed by P. lilacinum and F. equiseti. Conclusion The extensive morphological and molecular description and enzymatic detection provide crucial promotion for evaluating the potential of these local fungal isolates for future sustainable insect pest management in the specific ecological context of Assiut Governorate.