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Given its high nutritional value and capacity to grow in harsh environments, quinoa has significant potential to address a range of food security concerns. Monitoring the development of phenotypic traits during field trials can provide insights into the varieties best suited to specific environmental conditions and management strategies. Unmanned aerial vehicles (UAVs) provide a promising means for phenotyping and offer the potential for new insights into relative plant performance. During a field trial exploring 141 quinoa accessions, a UAV-based multispectral camera was deployed to retrieve leaf area index (LAI) and SPAD-based chlorophyll across 378 control and 378 saline-irrigated plots using a random forest regression approach based on both individual spectral bands and 25 different vegetation indices (VIs) derived from the multispectral imagery. Results show that most VIs had stronger correlation with the LAI and SPAD-based chlorophyll measurements than individual bands. VIs including the red-edge band had high importance in SPAD-based chlorophyll predictions, while VIs including the near infrared band (but not the red-edge band) improved LAI prediction models. When applied to individual treatments (i.e. control or saline), the models trained using all data (i.e. both control and saline data) achieved high mapping accuracies for LAI (R2 = 0.977–0.980, RMSE = 0.119–0.167) and SPAD-based chlorophyll (R2 = 0.983–0.986, RMSE = 2.535–2.861). Overall, the study demonstrated that UAV-based remote sensing is not only useful for retrieving important phenotypic traits of quinoa, but that machine learning models trained on all available measurements can provide robust predictions for abiotic stress experiments. [ABSTRACT FROM AUTHOR]

Background: The red palm weevil (RPW), Rhynchophorus ferrugineus (Coleoptera: Curculionidae), overruns date palm ranches in most Oases of Saudi Arabia and causes massive economic losses. Integrated pest management (IPM) of the RPW by biocontrol agents of bacterial isolates was the primary aim of the present study. Results: Thirty-seven bacterial isolates were isolated from the larvae of R. ferrugineus, which were collected from infested Phoenix dactylifera trees growing in different parts of Saudi Arabia. 16S rDNA sequencing showed that the isolated bacteria were: Serratia marcescens, Klebsiella pneumoniae and Bacillus thuringiensis. The potential of these isolates was tested against R. ferrugineus in the laboratory. The use of these three isolates showed significant mortality percentages against R. ferrugineus. The highest reduction in mortality was recorded at the concentration of 1 × 108 CFU/ml; B. thuringiensis isolate displayed the highest potency in mortal percentage rate (100%), 4 days post-treatment, followed by S. marcescens isolate after 5 days, and then K. pneumoniae isolate after 6 days. Conclusions: These results suggest that the use of these bacterial isolates was very useful in in vitro experiments, and it may consider those bacterial strains of interest as a potential biocontrol agent of R. ferrugineus. [ABSTRACT FROM AUTHOR]

Background: Tomato yield and quality are influenced by multiple factors, including conditions during cultivation, post-harvest handling and storage. Botrytis cinerea, the fungal pathogen causing gray mold disease, poses a significant threat to tomato production. This disease poses a serious challenge to tomato cultivation on a global scale, leading to significant crop losses and compromising food supply security. The purpose of this study was to assess the efficacy of three different bacterial bioagents, namely Pseudomonas fluorescens, Bacillus amyloliquefaciens and Pseudomonas chlororaphis, against B. cinerea. Results: From the rhizosphere of a tomato field, 22 bacterial isolates were collected. Among them, three isolates, designated as 1, 8 and 11, displayed notable antagonistic effects against Botrytis cinerea during in vitro testing and were selected for further analysis. The bacteria were identified as Pseudomonas fluorescens, Bacillus amyloliquefaciens and P. chlororaphis through 16S rRNA gene sequencing. The experiments demonstrated that these three isolates significantly inhibited the growth of the pathogenic fungus and promoted plant growth, with B. amyloliquefaciens emerging as the most effective inhibitor, displaying the highest antifungal activity. In vitro and greenhouse experiment suggest that the bacterial isolates hold considerable promise as natural antagonists for managing gray mold disease in tomatoes. The study further recommends using all three isolates for controlling the gray mold, with B. amyloliquefaciens showing the most significant potential, evidenced by its consistently lower disease severity scores, achieving the highest % efficacy (85.75) compared to control. Conclusions: The study emphasizes the significant potential of P. fluorescens, B. amyloliquefaciens and P. chlororaphis as effective bioagents to control tomato gray mold disease, B. cinerea. By directly targeting the fungal pathogen, these isolates provide an effective strategy for mitigating the adverse impacts of gray mold, contributing to higher crop yield and quality. Further research needs on open field trials and commercialization strategies for large-scale application of these bacterial bioagents. [ABSTRACT FROM AUTHOR]

Ectoparasitic arthropods are a diverse element of the Saudi fauna. Due to this, a survey of ectoparasites associated with rodents was conducted as a preliminary study in five districts of Hail region of northern Saudi Arabia for the first time. Ectoparasites extracted from 750 rodents were sampled and identified by recording their frequency of appearance. Results revealed that 1,287 ectoparasites infested 316 of the captured rodent hosts. These ectoparasites parasitized on four species of rodents including three species of rats Rattus rattus rattus, Rattus rattus frugivorus, and Rattus rattus alexandrinus and one species of mouse Acomys dimidiatus (Rodentia: Muridae). The ectoparasites belong to four different groups: ticks, fleas, lice, and mites. Ticks were the highest in the number, while fleas were the lowest among all the extracted ectoparasite groups. The collected ectoparasitic arthropods consisted of seven species. Ticks were of two species: Rhipicephalus turanicus and Rhipicephalus sanguineus (Acari: Ixodidae), fleas were of two species: Xenopsylla cheopis and Xenopsyllus conformis mycerini (Siphonaptera: Pulicidae), lice was a single species: Polyplax serrata (Anoplura: Hoplopleuridae), and mites were of two species: Laelaps nuttali and Laelaps echidninus (Mesostigmata: Laelapidae). The findings of the study showed that the intensity of infestation was varied between rodent host sexes, wherein females had the highest rate of parasitic infestation, and the parasitic index of appearance was very high for one group of parasites (i.e., ticks). The parasitic prevalence was 42.13 % on rodents, and mites were the most prevalent parasite species. Overall, this study was carried out to establish baseline data for ectoparasite-infested rodents in Hail region, Saudi Arabia, and may help for appropriate planning to control zoonotic diseases in this area. [ABSTRACT FROM AUTHOR]

Correction to: COVID-19 pandemic: impacts on bees, beekeeping, and potential role of bee products as antiviral agents and immune enhancers B Correction to: Environmental Science and Pollution Research (2022) 29:9592-9605 b https://doi.org/10.1007/s11356-021-17643-8 Funding The Deanship of Scientific Research (DSR) at King Abdulaziz University, Jeddah, Saudi Arabia has funded this project, under grant no. (FP-219-42 H). The authors, therefore, thanks DSR, King Abdulaziz University for financial and scientific supports. [Extracted from the article]