The article presents the results of studying of introduced apple varieties on the principle components of winter hardiness with the use of artificial freezing method.

The following varieties have been identified: the Gloster and Celeste apple varieties of German selection, the Ligol and Szampion Reno varieties of Polish selection, the Early Geneva variety of American selection, which have the genetic potential for resistance in the I and IV components of winter hardiness, and are also capable of withstanding frosts up to –20 °C in the autumn-winter period and restoring frost resistance when the temperature drops to –25 °C after thaws at +7 °C at the level of the standard highly winter-hardy Common Antonovka variety. Tissue damage to annual branches and vegetative buds did not exceed 1 point then. These genotypes are valuable breeding material when selecting parental pairs for creating varieties with the specific parameters and for state variety testing.

The studies to assess the early fruiting and growth rate of new Belarussian apple varieties, in particular the Aksamit and the Palanez varieties included in the State Register of Agricultural Plant Varieties in 2021, as well as the Krapach and the Ranak varieties, currently being tested by the State Inspectorate for Testing and Protection of Plant Varieties, on clonal rootstock with different growth vigor – 54-118 (semi-dwarf), М-26 and 62-396 (dwarf) were carried out in the garden of Department of Fruit Growing Technology in 2021–2023.

In the second year after planting, only trees of the Aksamit variety on the dwarf rootstock 62-396 began to bear fruit, when 100 % of the accounting trees began to bear fruit and an average yield of 1.65 kg/tree was obtained.

In the third year after planting, trees of the Krapach and Aksamit varieties began to bear fruit on all the studied root-stocks, trees of the Palanez variety began to produce fruits on dwarf rootstocks M-26 and 62-396, and trees of the Ranak variety began to produce fruits only on the dwarf rootstock 62-396.

In the varietal section, trees of the Aksamit and Krapach varieties were characterized by greater growth vigor, while trees of the Ranak variety were characterized by the least growth vigor. The apple trees of the studied varieties on semi-dwarf rootstock 54-118 were more vigorous (in terms of the cross-sectional area of the trunk (CSSA) and the growth rate of the trunk).

The Kalyadnaya is a new late-ripening pear variety of Belarusian selection suitable for dessert use. The variety was obtained at the RUE ‘Institute of Fruit Growing’ as a result of hybridization of the introduced Osnovyanska and Jūrate (2007) varieties. The variety is early-fruiting (enters into the commercial fruiting in the 3rd year on the Seedling Vinevki seed rootstock), resistant to scab and septoria, moderately susceptible to bacterial canker, productive (21 t/ha), suitable for long-term storage of fruits (up to 120 days under normal atmospheric conditions), has high commodity and taste qualities of fruits (average fruit weight – 210 g, marketability – 95 %). The profitability of the new variety is 157 %. The variety was submitted for state variety testing in 2023.

The research was carried out in the Biotechnology Department of the RUE ‘Institute of Fruit Growing’ in 2021–2023. The objects of the study were apple stem pitting virus (ASPV) and apple chlorotic leaf spot virus (ACLSV), along with apple trees of Papirovka Belsad, Champion, Redcraft, Aksamit, Belana, Antonovka common varieties, pear trees of Bere Alexander Luka and Conference varieties, reliably infected with the studied viruses. During different periods of the vegetation growing season, the presence or absence of viruses in leaves, buds, shoots, flowers, fruits, and seeds was assessed by ELISA and PCR (two modifications). It has been established that ACLSV and ASPV are present in varying amounts in plant organs during the vegetation period; their detection depends on the diagnostic methods used. The lack of stable results when diagnosing apple trees for ASPV using the PCR method with primers SPs635/SPas721 and the TaqMan probe SPp662 makes it impossible to recommend it for identifying plants affected by the virus.

The research was carried out in the Biotechnology Department and the Nursery Growing Department of the RUE ‘Institute of Fruit Growing’ in 2018–2023. Taking into account the phytosanitary recommendations of the European and Mediterranean Plant Protection Organization (EPPO), as well as quarantine and phytosanitary requirements of the Eurasian Economic Union, improved collections of fruit crops in Belarus have been updated, in particular: 22 varieties and 2 clonal rootstocks of apple; 8 varieties and 2 clonal rootstocks of pear; 11 varieties and 3 clonal rootstocks of plum and cherry plum; 16 varieties and 5 clonal rootstocks of cherry and sweet cherry; 4 varieties and 1 clonal rootstock of apricot; 5 varieties and 1 clonal rootstock of peach. Laboratory testing regimens for classification of fruit crops into the ‘original’ category are supplemented with 3 phytoplasma (including 2 quarantine) and 13 viral (including 3 quarantine) pathogens.

The article presents the results of assessment of economically valuable traits (winter hardiness, early fruiting, resistance to major diseases, commodity and taste qualities of fruits) of 8 domestic plum hybrids – 2011-01/15, 2011-01/09, 2011-01/29, 2012-02/60, 2012-02/61, 2012-02/17, 2012-02/20, 2012-02/30, obtained using the Venera, Volat, Kabardinskaya rannyaya, Kubanskaya rannyaya, Gilbert, Amitar, Stanley, Chachanska lepotitsa varieties as parental forms.

Based on the analysis of the data received, two selected forms that combine field winter hardiness, tasting evaluation of fruits and large-fruitedness at a high level: 2012-02/60 (Chachanska lepotica (Cacanska lepotica) op. p.) and 2011-01/29 (Gilbert × Venus) were identified as a new source material for further breeding work. Taking into account a set of economically valuable traits, the domestic plum hybrid 2011-01/15 (Kubanskaya rannyaya × Volat) was identified as promising for further variety testing.

The article presents data concerning the yield of the sweet cherry Hastsinets variety on clonal rootstock VSL-2 during the period of full fruiting of the garden (in the 11–15th years after planting) depending on the budding height in the nursery and the depth of tree planting under various placement patterns in the garden. It was established that during the full fruiting period, the budding of clonal rootstock VSL-2 in a nursery at a height of 60 cm, regardless of the depth of the seedlings rootstock, and a denser placement pattern of 4.5 × 1.5 m, with a planting distance of 1480 trees/ha, ensured a higher cumulative yield over five years of fruiting – at the level of 126.1 t/ha and obtaining a larger average yield from a unit area – by 5.2 t/ha, or 26 % more compared to a more rarefied planting pattern of 4, 5 × 2.0 m, with planting density of 1110 trees/ha.

Resulting from the performed study it was established that the maximum yield of sweet cherry varieties on the VSL-2 clonal rootstock with a placement pattern of 4.5 × 2.0 m over 5 years of commercial fruiting was obtained in the 7th year after planting the orchard with virus-free planting material: in particular, for the Hastsinets variety – 34.8 t/hectare, or 8.7 % higher than the potential yield of the variety declared by breeders on the seed mazzard rootstock (32.0 t/hectare), for the Krasnaya plotnaya variety – 32.2 t/hectare, or 7.3 % exceeding the potential yield of the variety on seed rootstock (30.0 t/hectare), for the Fatezh variety on clonal rootstock VSL-2 – 22.4 t/hectare, but 10.4 % less compared to trees on seed rootstock with a potential yield of 25.0 t/hectare, for the Iput variety on the clonal rootstock VSL-2 – 18.2 t/hectare, but 35.0 % less compared to trees on the seed mazzard rootstock with a potential yield of 28.0 t/hectare.

According to the highest cumulative and average yield over 5 years of commercial fruiting, the Hastsinets variety was distinguished, the yield of which was 102.7 and 20.5 t/hectare, respectively. Lower cumulative and average yield per unit area was obtained from the Fatezh variety – 77.1 and 15.4 t/hectare and the Iput variety – 77.8 and 15.6 t/hectare, respectively. The Krasnaya plotnaya variety took an intermediate position, the cumulative and average yield of which was 83.7 and 16.7 t/hectare, respectively.

The research was carried out in 2021–2022 in the laboratory of the fruit-growing department of RUE ‘Brest regional agricultural experiment station of the National Academy of Science of Belarus’. The objects of research were the in vitro regenerated garden strawberry plants of Asia, Alba, Florence varieties.

Studies on the influence of the spectral composition of light on the growth of garden strawberry in vitro have shown that the length of the branch crowns of regenerated plants increased when using spectral compositions of light: ‘red, blue, infrared, ultraviolet’ – (6.8 ± 0.14) mm at passage IV; ‘red, blue, infrared, ultraviolet’ – (5.7 ± 0.25) mm and ‘full spectrum’ – (6.1 ± 0.37) mm at passage V. The average number of leaves of regenerated plants increased when using the spectral composition of light: ‘white light (control)’ – (5.7 ± 0.42) pcs. on passage III and (5.7 ± 0.17) pcs. on passage V; ‘red, blue’ –  (5.0 ± 0.37) pcs. on passage II and (5.8 ± 0.52) pcs. passage III; ‘red, blue, orange’ – (5.7 ± 0.39) pcs. on passage III. To obtain a larger reproduction coefficient, it is recommended to use the spectral composition of the light of ‘full spectrum’ (the average value for four passages was 2.54 ± 0.16).

Microsatellite DNA markers are currently effectively used in studying the genetic diversity of berry crops and DNA certification of varieties.

Using the data of SSR analysis, molecular genetic passports were compiled for 48 samples of primocane raspberry (44 varieties, 4 hybrids), 7 of which are of Belarusian selection, 21 – Russian, 5 – Ukrainian, 5 – Polish, 4 – Dutch, 3 – Swiss, 1 – Romanian, 1 – English and 1 – American. Among the genotypes assessed, 5 samples are distinguished by the yellow color of the berries. 8 microsatellite SSR markers were used to create the passports. As a result, a high level of polymorphism of these microsatellite loci was shown and 113 alleles were identified. Depending on the locus, the number of alleles varied from 6 to 26. The RhM043 locus turned out to be the most polymorphic, and the RhM001 locus turned out to be the least polymorphic.

According to the results of research, the article presents a catalog of 13 genetic passports of primocane raspberry varieties included in the State Register of Agricultural Plant Varieties and being tested by the State Inspection for Testing and Protection of Plant Varieties of the Republic of Belarus.

The article presents the results of a comparative study carried out in the southern agroclimatic area of Belarus in contrasting hydrothermal regimes of vegetation periods of 2021–2023. During the study of phenology of seasonal development of 6 new introduced varieties of highbush blueberry with different ripening periods in particular early-ripening Chanticleer and Hannah’s Choice varieties; mid-ripening Bluegold and Harrison varieties and late-ripening Aurora and Rubel varieties, as well as regionalized Weymouth, Bluecrop and Elliot varieties, corresponding to the given groups of crop ripening, a significant impact of weather conditions on the timing of the onset of the main phenological phases was established. The most notable inter-seasonal differences in the timing of the phenological phases in the early and mid-ripening varieties were 9 and 11 days, respectively, while as for the late-ripening varieties they reached 17 days. However, all the tested blueberry taxa, along with the regionalized varieties, as the required amount of heat was reached increasing from the early to late-ripening varieties, managed to go through a full cycle of their development and form the harvest of berry products with distinct varietal differences in phenological rhythms, most expressively manifested during flowering and especially during fruiting. The earliest fruit ripening in new varieties of blueberries, which was 7–28 days ahead of that in the corresponding standard varieties, was identified in the Chanticleer and Rubel varieties, while the latest, with a delay of 3–5 days, was found in the Harrison variety.

The article presents the results of a comparative study carried out in the southern agroclimatic area of Belarus in contrasting weather conditions of the seasons 2021–2023. The regeneration capacity of 6 new introduced varieties of highbush blueberry with different ripening periods, in particular, early-ripening Chanticleer and Hannah’s Choice varieties; mid-ripening Bluegold and Harrison varieties and late-ripening Aurora and Rubel varieties, as well as related regionalized Weymouth, Bluecrop and Elliot varieties, used as references for comparison, was researched. A high dependence of the rhizogenesis processes and new shoot formations during the propagation of blueberry with softwood cuttings on the plant genotype and weather conditions of the growing period was established. The most pronounced rooting capacity of stem cuttings, comparable to that of the corresponding regionalized varieties, was demonstrated by the Chanticleer, Hannah’s Choice and Harrison varieties, while the least prominent capacity was characteristic for the Bluegold and Aurora varieties. Among the tested varieties, the greatest capacity of rooted cuttings to form new shoots compared to standard varieties was found only in the mid-ripening Bluegold variety, while the lowest – in both late-ripening Aurora and Rubel varieties. It was shown that Harrison variety was marked by the most significant total length of the newly formed shoots and the Rubel variety was marked by the least.

The grape plantations of the RUE ‘Institute of Fruit Growing’ were monitored for the presence of major and quarantine sap-transmissible viruses. 23 varieties were tested in the Department of Biotechnology and 26 varieties and hybrids of Belarusian selection were assessed in the Fruit Plants Breeding Department. In the grape collection plantations, the most commonly identified virus was GFkV, present in 23.5 % of all plants tested, including that of the Bianca, Regent, Crystall, Krasotka varieties and hybrids 2-15, 56-8. Diagnosis of plants during their dormancy period with the use of real-time PCR confirmed the presence of GFkV both in the phloem and in the leaf petiole of the grape plant.

The exceptions during real-time PCR-testing were the hybrid 52-18, in which GFkV was detected in the phloem only up to the 40th cycle (Cq – 38.93), and in the tissues of the leaf petiole the virus was not identified at all, and the Jupiter (Аs / Ас – 22.9), in which the virus was not identified in the phloem, but was identified in the petiole (Cq – 34.08). In tissue samples of the Platovsky and Bianca varieties, when diagnosed using real-time PCR, viral particles were identified in all tissues examined at cycle 30 and 40, depending on the variety, while according to the ELISA test, the virus was absent (Аs / Ас – 1.23 and 0.98 respectively).

Repeated ELISA testing of virus-free mother plants with a closed root system, kept under greenhouse conditions, during the period of active growth, confirmed the virus-free status.

The article presents the assessment results of the economic value of the hybrid fund obtained from free pollination of the Western European Catalan variety under the conditions of the breeding seed orchard. The high heterozygosity of the original maternal form was confirmed by the breeding traits under study. The possibility of obtaining transgressive forms in the first generation compared to the Catalan variety in terms of such parameters as the average weight of the nut (empirical splitting 1 : 4 : 4), shell thickness (1 : 3), kernel yield (7 : 1 : 6) has been shown. Genotypes with an earlier period of entry into the fruiting period and with a higher level of winter hardiness compared to the Catalan variety were not obtained. Four hybrids – 15-9/20, 15-9/41, 15-9/48, 15-9/50 – were selected as new original material with a set of main economically valuable traits for further breeding work.

The studies were carried out in 2021–2023 in the Nursery Growing Department of the RUE ‘Institute of Fruit Growing’. The article describes the research results on the biological characteristics of the growth and development of hazelnut plants in the mother plantation of horizontal layers.

Based on the results of the analysis of biometric indicators of hazelnut layers in the mother plantation, it was established that according to the parameters of height (113.6–134.5 cm), trunk diameter (11.0–11.1 mm), number of roots (9.8–15.8 pcs.) and the length of the root system (12.3–21.6 cm), the obtained layers met the requirements of the Ministry of Agriculture and Food of the Republic of Belarus. The number of unbranched hazelnut layers amounted to 72.0–83.0 % of the total number of separated ones. In connection with the existing requirements for the sowing qualities of hazelnut seedlings, which determine the mandatory presence of lateral shoots, there is a need to develop effective agricultural techniques for stimulating plant branching.

The residual effect of fruit storage of 6 varieties of highbush blueberry of different periods of harvest ripening depending on the storage period under conditions of ordinary gas atmosphere at a temperature of 4 °C was assessed. After a 3-day modeling of market conditions at a temperature of 18–20 °C, economically feasible yield of standard berries (90.0 % or more) was marked during storage from 2 (Spartan, Bluecrop, Goldtraube) up to 3 weeks (Bluejay, Sunrise, Brigitta Blue), after a 5-day modeling – from 1 (Spartan, Bluecrop, Sunrise, Goldtraube) up to 2 weeks (Bluejay, Brigitta Blue). When bringing the blueberry products to the consumer the yield of healthy fruits is significantly influenced by the sales terms (50.8 %) and the storage period (42.3 %), while the natural decrease of the mass of berries and the yield of non-standard fruits are influenced by factors such as sales terms (83.3 and 81.2 %, respectively) and the variety factor (10.5 and 7.5 %, respectively).

For blueberry products to be placed in retail chain stores at a temperature of 18–20 °C the most optimal storage periods of the fruits are from 1 week when selling products within 5 days to 2 weeks on condition of selling the berries within 3 days.

Field tests of the Nanoplant Ca-Si microfertilizer, carried out on 7 varieties of blueberry, have established that the new nitrogen-free calcium-containing preparation based on nanoparticles of micronutrients compounds exhibits high biological effectiveness at low doses of the preparation (CaO consumption is 330–500 g/ha per season at normal consumption rate of 42 g/ha CaO per treatment), which is 4–6 times less compared to the consumption rate of European equivalents. This opens up an opportunity of an economically justifiable increase in the frequency of treatments, which makes it possible to address the constant need of plants for calcium throughout the entire season – starting from bud swelling to mass fruiting period. The use of Nanoplant Ca-Si provides a stable substantial increase in the values of a range of key production-related indicators of blueberry: average weight and storage time at a temperature of (4 ± 1) °C. It was shown that the effectiveness of the new microfertilizer was especially pronounced in difficult weather conditions of the 2023 growing season, which led to a significant reduction in the shelf life of the crop in the control variant. The application of Nanoplant Ca-Si has doubled the shelf life of berries, which indicates the anti-stress effect of the new microfertilizer and justifies the feasibility of its use on blueberry plants not only as a source of calcium, but also as an adaptogen under unfavorable weather conditions.

The article presents the results of a two-year study to assess the suitability of 6 grape varieties (the Attica, Volodar, Kishmish zaporozhsky, Krasotka, Mars, hybrid 23-16-6-3) for the production of a product with low level of moisture content which is dried grapes.

Dried grapes account for 50 % of all dried fruits produced in the world. Dried grapes have high taste and nutritional qualities.

The solids content in fresh grapes was determined to be 15.7–21.5 %, soluble solids were defined to be 15.0–19.9 %. The mass fraction of solid substances in dried grapes was established to be 83.2–86.9 %. The amount of sugars in the varieties under study varied from 45.39 (Krasotka) to 51.95 % (hybrid 23-16-6-3).

Dried grapes are a product completely ready to be used, possessing good organoleptic characteristics. The average tasting score of dried grapes of all varieties was 4.2–4.7 points.

Conformity with the requirements of technical regulations of fresh grapes and the finished product was shown.

Seedlings of highbush blueberries are in demand as planting material. Blueberry is considered to be a hard-rooted berry crop. To improve root formation and further growing of rooted cuttings, a number of methods have been developed with the use of various preparations.

The review article presents basic information about present-day vegetative propagation methods of highbush blueberry: reproduction by layering, semi-hardwood and hardwood cuttings and microclonal propagation.

For commercial cultivation of highbush blueberry the propagation with hardwood and softwood cuttings should be used as it ensures the production of genetically homogeneous seedlings that retain variety identification and do not differ from maternal plants in terms of their economically valuable traits. The propagation of highbush blueberries with layers as an industrial method is not feasible from an economic point of view; this method is used by amateur gardeners. In the specialized nurseries of the Republic of Belarus microclonal propagation is considered to be the primary way of obtaining planting material of highbush blueberry.

The review article provides information on the spread and major symptoms of bacterial canker that is one of the most dangerous diseases of fruit plants caused by the phytopathogenic bacteria Pseudomonas syringae pv. syringae. Data on the development cycle, virulence factors and methods for identifying the pathogen, as well as on disease control measures, including the use of chemical and biological plant protection products, are given. The article presents basic information about the resistance of varieties and hybrids to bacterial canker in the natural environment and in vitro conditions.