Prediction of Pest Insect Appearance Using Sensors and Machine Learning.

The appearance of pest insects can lead to a loss in yield if farmers do not respond in a timely manner to suppress their spread. Occurrences and numbers of insects can be monitored through insect traps, which include their permanent touring and checking of their condition. Another more efficient way is to set up sensor devices with a camera at the traps that will photograph the traps and forward the images to the Internet, where the pest insect's appearance will be predicted by image analysis. Weather conditions, temperature and relative humidity are the parameters that affect the appearance of some pests, such as Helicoverpa armigera. This paper presents a model of machine learning that can predict the appearance of insects during a season on a daily basis, taking into account the air temperature and relative humidity. Several machine learning algorithms for classification were applied and their accuracy for the prediction of insect occurrence was presented (up to 76.5%). Since the data used for testing were given in chronological order according to the days when the measurement was performed, the existing model was expanded to take into account the periods of three and five days. The extended method showed better accuracy of prediction and a lower percentage of false detections. In the case of a period of five days, the accuracy of the affected detections was 86.3%, while the percentage of false detections was 11%. The proposed model of machine learning can help farmers to detect the occurrence of pests and save the time and resources needed to check the fields.

Antimicrobial Activity of Selected Essential Oils against Selected Pathogenic Bacteria: In Vitro Study.

The worldwide problem of infectious diseases has appeared in recent years, and antimicrobial agents are crucial in reducing disease emergence. Nevertheless, the development and distribution of multidrug-resistant (MDR) strains in pathogenic bacteria, such as Escherichia coli, Staphylococcus aureus, Salmonella Typhi and Citrobacter koseri, has become a major society health hazard. Essential oils could serve as a promising tool as a natural drug in fighting the problem with these bacteria. The current study aimed to investigate the antimicrobial effectiveness of tea tree (Melaleuca alternifolia (Maiden and Betche) Cheel), rosemary (Rosmarinus officinalis L.), eucalyptus (Eucalyptus obliqua L'Hér.), and lavender (Lavandula angustifolia Mill) essential oils. The antimicrobial properties of essential oils were screened against four pathogenic bacteria, E. coli, S. aureus, S. Tyhpi, and C. koseri, and two reference bacterial strains, while for the testing, the agar well diffusion method was used. Gas chromatography (GC) and gas chromatography-mass spectrometric (GC-MSD) analyses were performed on essential oils. The obtained results showed that M. alternifolia essential oil is the richest in terpinen-4-ol, R. officinalis and E. oblique essential oils in 1,8-cineole, and L. angustifolia essential oil in α-terpinyl acetate. In addition, the main bioactive compounds present in the essential oil of tea tree are rich in α-pinene (18.38%), limonene (7.55%) and γ-terpinene (14.01%). The essential oil of rosemary is rich in α-pinene (8.38%) and limonene (11.86%); eucalyptus essential oil has significant concentrations of α-pinene (12.60%), p-cymene (3.24%), limonene (3.87%), and γ-terpinene (7.37%), while the essential oil of lavender is rich in linalool (10.71%), linalool acetate (9.60%), α-terpinyl acetate (10.93%), and carbitol (13.05%) bioactive compounds, respectively. The obtained results from the in vitro study revealed that most of the essential oils exhibited antimicrobial properties. Among the tested essential oils, tea tree was discovered to demonstrate the strongest antimicrobial activity. The recorded MIC of S. Typhi was 6.2 mg/mL, 3.4 mg/mL of C. koseri, 3.1 mg/mL of E. coli, and 2.7 mg/mL of E. coli ATCC 25922, compared to M. alternifolia. Similarly, only S. aureus ATCC 25923 showed antimicrobial activity towards R. officinalis (1.4 mg/mL), E. oblique (2.9 mg/mL), and L. angustifolia (2.1 mg/mL). Based on the obtained results, it is possible to conclude that tea tree essential oil might be used as an ecological antimicrobial in treating infectious diseases caused by the tested pathogens.

Phytotoxic effects of irrigation water depending on the presence of organic and inorganic pollutants.

Irrigation is one of the most important uses of surface waters in the agricultural region of Vojvodina province (Serbia). The aim of the study was to assess the quality of water from Stara Tisa meander, based on the levels of pollution with metals, volatile compounds (VOC), pharmaceuticals, pesticides, and pathogenic bacteria, on sunflower, cabbage, cucumber, maize, barley, buckwheat, sorghum, radish, beans, and white mustard. Microbiological analysis was carried out using the dilution method and phytotoxicity assay according to ISTA filter paper method (germination energy (GE), germination (G), root and shoot length, fresh and dry weight). The sample was slightly contaminated with domestic, industrial, and agricultural xenobiotics and had low levels of nitrogen substances, metals, and organic micropollutants. Pesticides, metolachlor, tebuconazole, propiconazole, imidacloprid, and thiametoxam were detected at levels exceeding the maximum admissible concentrations (MACs), i.e., the sum value for neonicotinoids. The number of saprophytic (2.27 × 10(6) CFU mL(-1)) and coliform bacteria (5.33 × 10(2) CFU mL(-1)) was very high. The total number of sulphite reducing clostridia (10 cells mL(-1)) and Escherichia coli (5 cells mL(-1)) was very low. The GE and G of all tested plants, except sunflower, were not influenced by the total chemism of water sample. However, it inhibited root lengths of sunflower, cucumber, maize, and barley and stimulated shoot lengths of all species except maize and white mustard. These results indicate that it can be used for irrigation of cabbage and radish from the chemical point of view, but the microbiological traits should be considered prior to consumption since they are consumed raw. The overall results suggest that water from Stara Tisa should be purified before using for agricultural purposes.