The studies were conducted between 2022-2023.

   The purpose of the work was to analyze the relationship of hybrids and varieties of strawberries resistant and susceptible to anthracnose and to determine the putative allelic status of the anthracnose resistance gene Rca2.

   Selection of ISSR primers for identifying polymorphism and constructing dendrites of genetic similarity of 19 garden strawberry genotypes from the collection of the Federal State Budgetary Scientific Institution Federal Scientifi c Center for Horticulture. Th e eff ectiveness of ISSR primers was assessed by the ISSR-PCR method, followed by gel electrophoresis of ISSR-PCR products in an agarose gel. To assess the allelic state of the Rca2 gene, the SCAR marker STS-Rca2_240 was used. The genetic distance of the analyzed strawberry samples was determined using the Jaccard coeffi cient. Cluster analysis was carried out using the STATISTICA program (StatSoft ). The putative allelic status of the anthracnose resistance gene Rca2 in the studied varieties and hybrids was established. Diagnostic fragment of the STS-Rca2_240 marker, 240 bp in size. was found in the Alpha variety. Based on an array of genetic similarity coefficients, dendrograms were constructed, during the analysis of which the relationship of the studied variety samples was established. Promising forms were identifi ed that had a high degree of genetic similarity to varieties resistant to anthracnose, and forms that were closely related to susceptible varieties.

   Walnuts are a source of benefi cial nutrients (fatty acids, vitamins, phenolic compounds) and are high in calories. In the breeding of this cultivated plant, one of the key areas is selection for fruit quality. A modern cultivar must meet the standards of fruit appearance (large fruit, light kernel color, round shape, easy shell-kernel separation). The study of the genetic structure of walnut collections using microsatellite markers is no less relevant.

   The article aims to comprehensively evaluate the economically valuable traits of fruits and analyze the genetic diversity of promising elite walnut forms bred by the North Caucasian Federal Scientific Center of Horticulture, Viticulture, and Winemaking employing microsatellite DNA markers.

   Morphological fruit evaluation was carried out according to 13 traits. The biochemical analysis included total fat content, phenolic compounds, macronutrients (Na, K, Mg, Ca), and water-soluble solids. The molecular genetic analysis was performed using eight SSR markers: WGA001, WGA069, WGA376, WGA276, WGA009, WGA202, WGA089, WGA321. The comprehensive phenotypic and biochemical evaluation of fruits resulted in the identifi cation of elite forms superior to the check cultivar. For these elite forms, the fruit weight was 17-1-18 (13.36 g), MP-82 (14.80 g), YaB-18 (13.47 g); the kernel content was 17-2-23 (61.24 %), 17-5-5 (58.49 %), 17-2-16 (57.7 %); the fat content – MP-34 (68 %), 17-1-18 (61 %), 17-2-16 (62 %), MP-39 (60 %), YaB-5 (60 %). The microsatellite analysis revealed an average allele value per locus of 7.13, which indicates a high level of genetic heterogeneity in the studied sample of elite forms. Using the UPGMA clustering method and PCoA analysis, we revealed the presence of two genetically distinct groups. Th e first one includes large-fruited samples that exceed the check cultivar in terms of fruit weight (MP-82, YaB-18). In the second group, high-oil-bearing forms with a large percentage of kernel yield (17-1-18, YaB-5, 17-2-23, 17-2-16, MP-39, MP-34, 17-5-5) and forms with good shell-kernel separation (17-2-5, 17-2-16, 17-5-5, 17-5-10, MP-39, MP-67, MP-69, MP-170) predominated. Th us, it can be concluded that crossing genetically distant forms is promising not only for solving breeding issues, but also for preserving and increasing the genetic heterogeneity of the breeding walnut gene pool.

   The citrus collection of the FRC Subtropical Research Center of the RAS includes 144 genotypes and contains rare species and cultivars that are of great interest for use in production, breeding, and ornamental horticulture.

   The research examined 13 rare taxa: Citrus aurantifolia, C. aurantifolia ‘Foro’, C.×latifolia, C.×bergamia, C. ichangensis, C. limon ‘Del Brasil’, C.×limonelloides, C.×limetta ‘Chontipico’, C. maxima ‘Sambokan’, C. medica, C. medica var. sarcodactylus, C.×meyeri, C.×myrtifolia.

   The research established the times and differences in the passage of the main phenological phases, namely bud opening and flower-bud formation, flowering, second and third active growth, fruit ripening. The beginning of the growing season of the studied objects was registered in the second and third decades of March; the difference between the early onset for C. aurantifolia (16.03) and the late onset for C. ichangensis (01.04) is 14–20 days. Two active growth periods were established for C. ichangensis, C. limon ‘Del Brasil’, C. maxima ‘Sambokan’, and C. medica, while the other citrus taxa under study had three periods of active growth. According to their flowering dates, taxa with early (April 11–13), middle (April 18–19), and late (April 23–28) flowering time were identified. Long flowering (29–36 days) is typical for taxa with early flowering. Remontant taxa, i. e. C. aurantifolia, C. aurantifolia ‘Foro’, C.×latifolia, C.×bergamia, C.×limonelloides, C.×limetta ‘Chontipico’, C. limon ‘Del Brasil’, C.×meyeri were identified. From the beginning of the growing season to fruit ripening, the effective heat summation was determined to be 4710–5250 ℃. The study also identified taxa with late fruit ripening, namely C. medica and C.×myrtifolia (third decade of December – first decade of January). The taxa with the best commercial qualities and biochemical composition of fruits were C. maxima ‘Sambokan’, C.×meyeri, and C.×limetta ‘Chontipico’.

   The field agrochemical experiment conducted in 2021–2023 was designed to study the influence of drip irrigation and two methods of mineral fertilizer application on the components of productivity of columnar apple plants when grown on cultivated loamy textured sod-podzolic soil in the conditions of Moscow Oblast. Drip irrigation, solid fertilizer application, and fertigation were found to have different eff ects on plant productivity indicators. Th e eff ects largely depend on the cultivar and weather conditions. Drip irrigation in conjunction with solid fertilizers increased plant productivity to the greatest extent. Thus, the ‘Ostankino’ cultivar yielded by up to 2.16 kg/tree more, i. e. the productivity rose by 27.1 % compared to the controls. In the ‘President’ cultivar, yield per tree increased by up to 2.18 kg/tree (by 35.4 % compared to the controls). The irrigated and fertilized variants of the experiment were distinguished by higher vegetation productivity values for the ‘President’ cultivar plants. For this cultivar, the highest total growth rate was in the fertigation-drip irrigation variant with an increase of up to 459.2 cm/tree in 2022. Th e average growth over two years was 16.5% higher than in the control group. In the ‘Ostankino’ cultivar, the total length value of shoot growth during irrigation and solid fertilizer application decreased compared to the control group by up to 245.2 cm/tree. On average, over two years it decreased by 15.7 % compared to the controls. In the fertigation-drip irrigation variant, there was a decrease in the ammonia nitrogen content in the soil compared to the other variants. As a result, the total mineral nitrogen content in the soil layer to a depth of 60 cm was minimal. Th e highest value of ammonium content and total nitrogen in the rhizosphere were observed in the variant with drip irrigation and solid fertilizer application.

   The article discusses the design of a robotic device intended for effective apple fruit harvesting with minimum damage. The research was conducted in the Federal Scientific Agroengineering Center VIM from 2020 to 2023. The developed device is equipped with specialized mechanisms and sensors designed to reduce the negative eff ects on apples during harvesting.

   The study aims to justify the parameters of the robotic device for apple fruit picking and to conduct laboratory experimental studies of the grip strength eff ect on fruit damage during robotic fruit harvesting.

   A classification of gripping devices was developed based on the analysis of their design parameters and types. A concentric three-fingered gripper tool with rotating and sliding elements added to the gripping device was selected as the prototype device. As a result of studying the size and weight parameters of apples of the ‘Jonathan’ and ‘Granny Smith’ cultivars, data were obtained that enable one to describe the characteristics of these fruits more fully. Th e grapho-analytical method was employed to select the optimal geometric parameters of the gripper claws. We designed a robotic gripper which has several components, including gripper claws and a movable base. A laboratory setup was developed to simulate the operation of the manipulator and conduct experiments. Th e setup makes it possible to create conditions close to the actual manipulator operation and study the processes of grasping and holding fruits. The three-factor experiment allowed us to analyze the impact of the grip strength of the gripper claws, as well as the distance from the fruit to the gripper on the damage to fruits. It has been determined that these parameters have a signifi cant eff ect on the process of grasping and holding fruits. Entirely optimal values of these parameters contribute to reliable holding of a fruit in the gripper claws with minimal damage. As a result of analyzing the size-mass parameters of fruits, we found the average size and weight of apples of the Jonathan and Granny Smith cultivars. Th e design parameters of the robotic device were justifi ed. A 3D robotic gripper model was developed. We also manufactured an experimental robotic gripper model which underwent laboratory tests. As a result, the parameters of the grip strength and the distance from the fruit to the gripper were identified.

   With the development of the trend towards robot facilitation of farmers’ work, the need for their most effective implementation in the agricultural sector (including horticulture) becomes more urgent. In materials science and agricultural freight robotics, there is still no univocal opinion on what structural materials are most preferable based on technical, economic, and environmental criteria. Authors rarely relate the capabilities of structural materials for robots to a decrease in specific ground pressure. Engineering needs studies comparing different structural materials most suitable to produce agricultural load-carrying robots.

   This article aims to conduct a comparative investigation of three variants for an agricultural robotic truck with a steel, aluminum, or fiberglass body to justify the most acceptable material.

   Aluminum was hypothesized to be superior to steel and fiberglass as an agricultural freight robot material. Three robot versions were constructed using steel, aluminum, or fiberglass. They were then tested under field conditions, and the obtained results were recorded. In economic terms, using fi berglass is more justifi ed than aluminum. This is explained by the reduction in robot operating costs due to the lower density of fiberglass (1,900 versus 2,700 kg/m³). However, in terms of the environmental criterion, fiberglass loses because it contains formaldehyde and is difficult to recycle.