A nonwoven fiber made of polylactide/natural rubber with a rubber content from 0 to 15 wt.% was obtained by electrospinning from a solution. The water sorption test showed that the addition of natural rubber into the polylactide matrix did not significantly affect the degree of water absorption of the fibers, which was in the range of 48.9–50.6%. The melt flow rate only increased by 0.5 g/10 min at a content of 15 wt.% natural rubber. The thermal characteristics after 120 days of degradation in distilled water and UV irradiation (50 h) at a wavelength of 365 nm were determined using differential scanning calorimetry. Changes in the values of the phase transition temperatures and the degree of crystallinity were determined. It was determined that the fiber samples from all compositions retained the propensity for photo- and hydrolytic degradation.

In this work, PLA/NR electrospun fibers were used as substrates for growing basil. Thermal characteristics of initial samples and after 60 and 220 days of degradation were determined using differential scanning calorimetry. In the process of disintegration, the melting and glass transition temperatures in PLA/NR composites decreased, and in PLA fibers these values increased slightly. TGA analysis in an argon environment confirmed the effect of NR on the thermal degradation of PLA/NR fibers. After exposure to the soil for 220 days, the beginning of degradation shifted to the low-temperature region. The dynamic characteristics of the fibers were determined by the EPR method. A decrease in the correlation time of the probe-radical in comparison with the initial samples was shown. FTIR spectroscopy was used to analyze the chemical structure before and after degradation in soil. In PLA/NR fibrous substrates, there was a decrease in the intensity of the bands corresponding to the PLA matrix and the appearance of N-H C-N groups due to biodegradation by soil microorganisms.

Plant diseases of an infectious nature are the reason for major economic losses in agriculture throughout the world. The early, rapid and non-invasive detection of diseases and pathogens is critical for effective control. Optical diagnostic methods have a high speed of analysis and non-invasiveness. The review provides a general description of such methods and also discusses in more detail methods based on the scattering and absorption of light in the UV, Vis, IR and terahertz ranges, Raman scattering and LiDAR technologies. The application of optical methods to all parts of plants, to a large number of groups of pathogens, under various data collection conditions is considered. The review reveals the diversity and achievements of modern optical methods in detecting infectious plant diseases, their development trends and their future potential.

Non-woven polylactide-natural rubber fiber materials with a rubber content of 5, 10 and 15 wt.% were obtained by electrospinning. The thermal, dynamic, and mechanical properties of the fibers were determined. It was shown that the average fiber diameter increased with adding of the NR content, while the linear and surface densities changed slightly. Using the differential scanning calorimetry, the thermal characteristics were obtained. It was found that the glass transition temperature of polylactide increased by 2–5 °C, and the melting temperature increased by 2–4 °C in the presence of natural rubber in the samples. By the method of electronic paramagnetic resonance at T = 50 and 70 °C it was determined that the mobility of the amorphous phase in PLA/NR fibers increased with the addition of NR. The adding of NR at a content of 15 wt.% increased the value of elongation at break by 3.5 times compared to pure PLA.

Fusarium and late blight (fungal diseases of cereals and potatoes) are among the main causes of crop loss worldwide. A key element of success in the fight against phytopathogens is the timely identification of infected plants and seeds. That is why the development of new methods for identifying phytopathogens is a priority for agriculture. The terahertz time-domain spectroscopy (THz-TDS) is a promising method for assessing the quality of materials. For the first time, we used THz-TDS for assessing the infection of seeds of cereals (oats, wheat and barley) with fusarium and potato tubers of different varieties (Nadezhda and Meteor) with late blight. We evaluated the refractive index, absorption coefficient and complex dielectric permittivity in healthy and infected plants. The presence of phytopathogens on seeds was confirmed by microscopy and PCR. It is shown, that Late blight significantly affected all the studied spectral characteristics. The nature of the changes depended on the variety of the analyzed plants and the localization of the analyzed tissue relative to the focus of infection. Fusarium also significantly affected all the studied spectral characteristics. It was found that THz-TDS method allows you to clearly establish the presence or absence of a phytopathogens, in the case of late blight, to assess the degree and depth of damage to plant tissues.