The boxwood moth Cydalima perspectalis Walker is a dangerous adventive pest, the control of numbers and harmfulness of which cannot be carried out by traditional chemical insecticides in forest park sanitary, recreational, protected and resort areas. The article presents the dynamics of the development of the boxwood moth in the Perkalsky Arboretum in the period 2018-2023 and the results of laboratory tests of the spore-based entomopathogenic fungus Akanthomyces muscarius in the form of a wetting powder, strain G - 033 VIZR. The effectiveness of the preparative form was slightly lower than the effectiveness of the standard. It was established that boxwood moth caterpillars of older instars have higher resistance to entomopathogenic fungi compared to larvae of younger instars. The protective effect of entomopathogenic fungi is more pronounced at low and medium pest infestation of plants.

The activity of peroxidase, catalase and polyphenol oxidase in the buds of some Ficus genus genotypes with varying degrees of frost resistance from December to March for three years was studied. The activity of peroxidase was determined spectrophotometrically by the rate of benzidine oxidation reaction, polyphenol oxidase – colorimetrically in the presence of pyrocatechol and p-phenylenediamine, catalase – by the titrimetric method.

Analysis of changes in enzyme activity during the cold periods of the three years of the study showed that the activity of peroxidase and polyphenol oxidase depends on the specific weather conditions of the year. Catalase activity revealed species specificity and minimal dependence on weather conditions, increasing during the entire cold period over the course of three years of research. At the same time, the dynamics of the activity of these enzymes in the buds of resistant and unstable genotypes differed. It is assumed that these enzymes are involved in the implementation of protective mechanisms of the studied genotypes of the genus Ficus under lowtemperature stress. Throughout the entire study period, unstable genotypes differed from resistant genotypes by a higher level of activity of the studied enzymes in the buds. Indicators of the activity of peroxidase, catalase and polyphenoloxidase in the buds can be used as biochemical markers to assess the level of frost resistance of genotypes of deciduous species of the genus Fiсus.

For the first time, the geographical aspects of the study of ivy cultivars, a valuable ornamental foliage plant, are considered. The role of some countries in the creation of a modern assortment that number 1354 cultivars is analyzed. In total, 25 countries participated in ivy selection, which are divided into five groups according to their contribution. The main world centers of ivy selection have been identified, which include the USA, Great Britain and Germany. These countries account for 909 cultivars (71.35%). The second group consists of the Netherlands and Denmark with 215 cultivars (16.88%), the third is Japan, France, Russia (74 cultivars, 5.81%). Other countries play a minor role in ivy selection. The main centers of ivy selection were formed not only as a product of the powerful development of the market for ornamental plants, but also thanks to the active work of a pleiad of enthusiasts of this ornamental plant with commercial or research talents.

The effectiveness of actively increasing the reproduction of forest resources is possible only through the intensification of the entire forest growing cycle, covering every stage of silvicultural production. Today, the time has come to consider technologies for growing pine not only with an open root system (PMOC). Growing coniferous planting material in the open ground of forest nurseries is a rather labor-intensive process, largely dependent on external factors that change during the season. Modern technologies of silviculture production are focused on the mechanized execution of work on planting cultures and caring for them, which leads to certain features when placing planting sites. Moving on to silvicultural production of planting material with a closed root system (PMCS), this drawback is practically absent from planting material. Experiments carried out by many foresters in our country have shown that mycorrhizal pines develop many times faster than uninfected plants. Studying pine seedlings in a private nursery for growing seedlings with PMCS, we identified the most characteristic of three forms for mycorrhizae: forked, nodule and simple mycorrhizae. The root system of mycotrophic woody plants differs significantly from non-mycotrophic ones. This can be seen both morphologically and anatomically. We determined the “active” and total root surface of annual pine seedlings. The data obtained convince us that without the additional absorbing surface of the mycelium of the mycorrhizaforming fungus, the relatively small surface of the roots system would not be able to ensure the transfer of the required amount of water and plastic substances to the leaves during the two-rotation method of cultivation. An increase in the number of rotations affects to the formation of root systems of seedlings, and leads to lethal consequences - unformed seedlings do not tolerate the winter period in hardening areas. The growth ends of the roots initially have the ability to absorb water and plastic substances, however, the number of these rooting ends is very small. Water and plastic substances are absorbed mainly by short sucking roots entwined with mycorrhiza-forming hyphae. The sucking endings of roots, suberized and entwined with fungal hyphae, do not die off, but remain alive for a number of growing seasons. Under favorable conditions, it is possible for the mycorrhizal covers to break through with renewed growth by the root. In the conditions within the Prebaikalia region, Scots pine seedlings form mycorrhiza without the use of a mycorrhiza-forming agent, develop normally and meet the necessary parameters for seedlings with PMCS.

The fruits of Prunus domestica L. are a healthy food product for humans, both fresh and processed. Plum genotypes from various natural regions significantly enrich the source material with sources and donors of valuable traits when used in breeding. The plum collection of the Nikita Botanical Gardens (FSBI "NBG-NSC") contains more than 200 cultivars from various growing regions. In addition to domestic cultivars, it includes introduced cultivars from 13 countries of Europe and America, from Russia and the countries of the former UIS, which amounts to 66.8% of the total number of genotypes.

Cultivars of different origins differ in tree crown habitus, ripening time, weight and taste of fruits, yield, time of fruiting, resistance to low negative temperatures, field resistance to drought and tolerance to various fungal pathogens.

When performing the studies, we were guided by generally accepted methodological recommendations. As a result of many years of study, cultivars have been selected that are sources of valuable economic and biological traits that can be used in breeding to improve the quality of fruits, increase productivity and adaptability to unfavorable environmental stress factors. 76 cultivars with a complex of valuable traits have been identified. 17 cultivars were selected - with very large fruits, seven - with ultra-early fruit ripening, 14 – with very late ripening, eight cultivars characterized by a small crown habit, 18 - high early fruitfulness, 21 – high self-fertility; 25 – high and regular yield, eight – high resistance to drought, 21 – high frost resistance. Involving selected cultivars with certain economically valuable traits in hybridization will increase the efficiency of the breeding process to create new competitive cultivars for industrial horticulture and resolve issues of import substitution.

Modern forestry requires effective methods for studying seed productivity and quality of seeds formed under various growth conditions. Deciduous woody plants seeds, as a rule, are characterized by deep dormancy, they also differ in a variety of sizes and shapes, what makes them difficult objects for determining the number of full-fledged seeds in a batch that do not have external defects and signs of the presence of live pests or their larvae. The method of microfocus radiography (X-ray) is one of the innovative, reliable and fast methods for etermining the quality of seeds. The report presents the results of an X-ray assessment of the quality of seeds
formed in 2022 by trees of various species of maple (Acer) and elm (Ulmus) growing in the arboretum of the Botanical Garden of the Samara University. The share of full-fledged seeds for Acer species increased in the following order: A. mono (33.2%) <A. pseudosieboldianum (33.3%) <A. platanoides (43.9%) <A. pseudoplatanus (46.4%) <A. negundo (58 .2%) <A. campestre (68.2%) <A. saccharinum (96.4%). Species of the elm genus, which characterized by the rapid formation of an exceptionally large number of seeds, had a significant proportion of them turn out to be empty-grained. We found that the proportion of full-fledged seeds was slightly higher in the local species Ulmus laevis (about 22%) and lower in the two introduced species U. minor (less than 10%) and U. pumila (10%). For a number of species, damage to seeds by insects was revealed.

The article presents data on the results of repeated freezing of flower buds of 30 zoned peach cultivars of NBG breeding. Cultivars with very high, high and medium frost resistance have been identified. In general, according to experience, out of nine cultivars belonging to the North Chinese group, five (55.6%) were isolated - with high and very high frost resistance of flower buds, and out of 21 cultivars of the Iranian group – 14 (66.7%) frost-resistant samples, which shows a higher frost resistance of the Iranian eco-geographical group cultivars. Determining the frost resistance of flower buds made it possible to substantiate the placement of cultivars in the agro-climatic regions of the Crimea. Nine cultivars with an average level of frost resistance are recommended to be placed in favorable agro-climatic regions. For unfavorable areas, 21 cultivars with very high and high frost resistance of flower buds are recommended, which can also be successfully grown in favorable agro-climatic regions of the Crimea.

The materials of IGS, COCERAL, USDA, etc. were analyzed by economic-statistical, abstract-logical, expert methods source for the development of "malting barley-beer" value chains in the leading EU-27 +UK countries. There is a gradual reduction in the acreage of EU-27+UK barley (10.5 million hectares in 2022), and gross harvest (52.2 million tons), including 8-9 million tons produced for malting. Recommendations of the European programs: C.B.M.O., VLB, MBC, with evaluation of agronomic and qualitative indicators in dynamics and production, play a decisive role for the commercial success of the cultivar. The commercial success of the cultivar is judged by the breeding areas and the amount of royalties. Breeding programs are concentrated in France (RAGT, Limagrain, Secobra), Germany (KWS, Breun, Saaten Union), Denmark (Sejet, Nordic Seed). Due to the possible departure of foreign companies from the Russian Federation, the creation of national program of variety assessment is required.