Purpose. Morphological and organoleptic evaluation of oyster mushroom strains for selection of highly productive cultivars assortment with valuable consumer properties for winter and summer cultivation and suitability for sale in fresh or processed form were investigated. Methods. The scheme of the experiment included six strains of oyster mushrooms belonging to two species: Pleurotus ostreatus (5 strains: 2301, Z, 2316, 2456, 431) and P. pulmonarius (2314). Laboratory, laboratory-industrial and statistical methods are used. Results. The dynamics of agrochemical parameters of substrates obtained by the method of aerobic fermentation in the high layer proved their optimality according to the main criteria and compliance to regulatory documentation. The biological efficiency of the strains was in the range of 40–78.9%. The highest weight of clusters was found in the “summer” strain 431 (430.7 g). The highest weight of the fruiting body was determined for the strain 2301 (15.2 g), the lowest – for the 2456 (3.3 g). Conclusions. The values of biological efficiency of strains was determined. The highest average values for the first flush of fruiting had strains 2316 (78.9%) from the “winter” group (A) and 431 (78.4%) from the “summer” group (B). According to the results of statistical analysis, significant differences were revealed between the studied strains in the main morphological indicators of clusters. It was found that the mass of clusters of «winter» cultivars is much less dependent on the strain type (220.8–273.4 g) than that of «summer» cultivars (83.4–430.7 g). The index of the asymmetry coefficient of the cluster, which can be useful for calculating the required container sizes was proposed. It was determined that the morphological features of fruiting bodies had significant differences in all studied parameters. In particular, the A group strains differed in size and weight. It was proposed the index of weight loss of the crop coefficient, which shows the ratio between the cap and stipe of the fruiting body and make it possible to predict the amount of mushroom raw material that will be sold in the form of caps, and the amount of raw material that can be processed into minced mushroom, powder and others. The best coefficient was obtained for the fruiting bodies of strain 2314 (0.87), and the worst – for 2456 (0.59), which, accordingly, is not recommended for sale by individual fruiting bodies. It was found that the fruiting bodies of high-yielding strains 2316 and 431 had a number of organoleptic defects.

Purpose. Considering ways to solve issues related to soil cover study at the institutions for plant varieties examination. Methods.Fieldandanalytical ones. Results. Issues are identified that arise during soil sampling at institutions for plant varieties examination within the state system of plant varieties protection. The author considered in detail the current soil sampling techniques for agrochemical tes­ting for humus, nitrogen (compounds to be easily hydrolyzed), mobile P2O5, exchangeable K2O, hydrolytic acidity and others. Attention was paid to violation of methodological requirements concerning the time of soil sampling and number of samples for agrochemical testing at the experimental field, to the lack of devices for meteorological observation and appliances for soil and leaf diagnostics. The article also touches upon the issues associated with the study of soil cover at fields with scientifically-based crop rotation that belong to institutions for plant varieties examination within the state system of plant varieties protection. Conclusions. It should be necessary to follow recommended practice when sampling at elementary sites for agrochemical testing and performing all operations in accordance with crop cultivation flowcharts. General recommendations for agrochemical testing of fields in case of conventional crop rotations in farms are not suitable for fields with scientifically-based crop rotations at institutions for plant varieties examination.