The purpose of this research is to study the effect of deep loosening of row spacings on the physical properties of the soil and yield of organic potatoes. Two variants of soil cultivation were used in row spacings: usual and 25 cm deep. The soil cultivation was carried out with a row-crop chisel cultivator. Its design was developed at the institute. Analysis of the data obtained as a result of experimental studies showed that deep loosening of row spacings had a positive effect on soil compaction both in the inter-row width and directly in the plough ridge. The soil compaction in the row spacing during normal tillage was in average above 20 %, and in the ridge by an average of 13 % compared to deep tillage. The assimilation of moisture by the soil with when using of deep loosening of row spacings also had a positive trend, especially under condition of a large amount of precipitation in a short period of time. Thus, with a loss of 34 mm, the soil in the variant with loosening the row spacings in a larger volume absorbed moisture and the moisture indicators increased sharply in layers, at 15 cm by 27 %, at 25 cm by 20 %, at 35 cm by 5 %. Potato yield increased by 8.7 % when using deep loosening of row spacings. The obtained results of experimental studies should be used as recommendations when carrying out technological operations aimed at caring for potato plantings.

The authors showed that a convenient, accurate and fast way of assessing the degree of influence of environmental factors on plants was needed to optimize photoculture. They emphasized the importance of non-destructive monitoring of crops physiological state of, for which they used phenomics technologies, for example, remote sensing using hyperspectral cameras.(Research purpose) To reveal the possibility of using hyperspectral imaging to determine the plant developmental stability.(Materials and methods) As a measure of the favorable impact of environmental factors on the growth and development of plants, their developmental stability was taken, numerically characterized by the fluctuating asymmetry value. The authors proposed to use vegetation indices determined from the leaf reflection spectra as a bilateral feature. The object of experimental research was juvenile cucumber plants. The studies were carried out in laboratory conditions. The spectral characteristics of cucumber leaves grown under different light quality of radiation were determined using a Specim IQ hyperspectral camera. Information on the spectral reflectances was extracted from the resulting data hypercube. As an example calculations were performed for Normalized Difference Vegetation Index.(Results and discussion) The authors revealed differences in the productivity indicators of plants grown under different light quality. They revealed a significant frequency of occurrence of Normalized Difference Vegetation Index asymmetry in two halves of the cucumber leaf surface. The fluctuating nature of this asymmetry was confirmed. They found that with a light quality providing a higher productivity of plants, lower values of fluctuating asymmetry were observed, which indicate greater stability of plant development.(Conclusions) The authors proposed a method for determining the plant developmental stability using a hyperspectral camera. The method was based on the assessment of the fluctuating asymmetry of vegetation indices calculated for points on the leaf surface, characterized by the same location conditions relative to the border of its left and right halves. A preliminary assessment of the possibility of determining the developmental stability by the results of phenotyping using the example of cucumber plants showed the feasibility of the method and its practical applicability.

Optical leaf properties serve as an important indicator of complex plant physiology under a broad range of environmental conditions. However, available relevant measuring instruments have several disadvantages. The study aimed to design a leaf photocolorimeter as a tool for a further comprehensive assessment of the impact of environmental factors on plants and optimisation of artificial plant lighting. The technical objective was to make this device user-friendly and improve its functional and ergonomic characteristics. The device had the following parts: the RGB LED block of BL-L515RGBC-CD type with the radiation peaks at 430 nm (blue), 525 nm (green) and 630 nm (red); a photodetector; a processor with Arduino UNO Rev3 board; LCD display; a keyboard; a power supply unit; a clamp; a thickness sensor; a lever; and a secure digital memory card. The measured leaf thickness, transmittances and optical density in spectral ranges, as well as the measurement time and sample identification record, formed a row in the database stored in the device's memory. Variation in the pigment content in cherry leaves, optical characteristics of plant leaves grown under natural conditions, and optical characteristics of tomato leaves under artificial lighting were measured in a set of experiments. The use of the device in the experiments provided for objective estimation of the plant leaf ageing process by the content of various pigments in the leaves. For this purpose, the specific optical density needed to be measured. The process estimation by leaf optical properties had a lower data variance and was more reliable than estimation by other biometric parameters. The designed device tests proved its wide capabilities in the rapid assessment of the growing plant status. Its practical application in greenhouse horticulture can help improve crop performance and yield quality.