Trellis System Research Articles

Determination of the Factors Effective in Reaching the Objectives of Agricultural Support: Example of the Wire Trellis Systems in Viticulture Farming in Diyarbakır

Determination of the Factors Effective in Reaching the Objectives of Agricultural Support: Example of the Wire Trellis Systems in Viticulture Farming in Diyarbakır

СОРТ ВИНОГРАДА ХОУП: ХАРАКТЕРИСТИКИ И ВОЗМОЖНОСТИ ИСПОЛЬЗОВАНИЯ

This article presents the results of a study of a new grapevine variety called Hope, developed within the Breeding Program of the University of Arkansas, USA. The research was conducted at experimental plots of the All-Russian Research Institute of Viticulture and Winemaking – Branch of Federal State Budget Scientific Institution «FRARC». The Hope grapevine variety possesses several positive characteristics: it belongs to the seedless category of the second class, has dense flesh, and exhibits a complex and rich flavor and taste profile. The average weight of a cluster is 320 grams, while the average weight of a berry is 4.2 grams. The Hope variety has high yield potential, reaching up to 124 quintals per hectare. It shows vigorous vine growth and good resistance to diseases. Additionally, it has a good winter hardiness. Standard methodologies and vineyard cultivation techniques were used in the study. The vineyards where the research was conducted were non-irrigated and grafted, using the Oppenheim SO4 rootstock, with bilateral cordon training and a planting scheme 3×1.5 meters. The results indicated that the Hope variety has an early ripening period (requiring 118 days from bud break to full berry maturity). It has promising for use in winemaking and does not require yield regulation measures. Overall, the Hope grape variety is of interest for commercial cultivation in industrial vineyards. Its economically valuable qualities and attributes make it appealing for consumption in fresh form, wine production, and the production of dried products. It can also be included in the breeding programs of scientific institutions for further development and improvement of grape varieties.

Spur Pruning Leaving One Bud is an Interesting Viticultural Strategy to Control Bud Acrotony in Bolivian Vineyards

Bolivian viticulture is mostly found in the Central Valley of Tarija, which is characterised by a subtropical climate with high thermal oscillation in winter that results in low accumulation of chilling units. Such climatic conditions accentuate acrotony in vines, which affect budburst uniformity and, consequently, yield and bunch quality at harvest. The aim of this study was to evaluate the effect of different spur pruning strategies on the percentage of budburst and fertility of buds located in different nodal positions in both wine and table grape varieties growing in the Central Valley of Tarija. The results show that allocating spurs with fewer buds improved the budding of most of the distal buds studied. This was noted in both the wine and table grape cultivars, but mostly in the latter. Spur pruning leaving one bud improved the percentage of budburst and the fertility of the distal buds in Cabernet Sauvignon, Cardinal and Ribier, thereby preventing bud acrotony, compared to spur pruning leaving two buds. Spur pruning leaving two buds improved the budburst of latent buds in Cabernet Sauvignon. Therefore, to avoid acrotony patterns, viticulturists should perform pruning leaving one bud.

Aplicação de cianamida hidrogenada e Budbreaker® na quebra da dormência e produção de BRS Cora (Vitis labrusca L.), submetida a poda mista

The objective of the work was to evaluate the effect of applying Dormex® and Budbreaker® on breaking dormancy and producing the cultivar BRS Cora (Muscat Belly A x H. 65.9.14Vitis) grown in a trellis system, in the region of Pinto Bandeira, Serra Gaúcha. A completely randomized design was used in a scheme with six treatments, as follows: T1 - control without application of sprouting inducer; T2, T3 and T4 - concentration of 1, 2 and 3% of Budbreaker®, respectively, and T5 and T6, concentration of 4 and 6% of Dormex® (hydrogenated cyanamide), respectively; 2% mineral oil was applied to all levels of sprouting inducers. The response variables were: production per plant, bunch mass and number of bunches; sprouting index and fertility, as well as physical and chemical characteristics, the content of soluble solids, considering evaluation in sticks and spurs. There was no response to the application of sprouting inducers, considering the conditions of high sum of cold hours that occurred in the winter of 2022, which together with the low cold requirement of the cultivar BRS Cora (Vitis labrusca L.), benefits the sprouting index , both in the sticks and spurs. Production reached values between 41 and 54 tons/ha and the solids content varied from 15 to 16, considered adequate for the productive characteristics of the variety and the conditions under which the experiment was carried out.

Performance of ‘Chambourcin’ Winegrape on 10 Different Root Systems in Southern Missouri, USA

In the midwestern United States, especially Missouri, winegrape (Vitis sp.) growers mostly plant interspecific hybrids, which are well adapted to the climate and pests of the region. ‘Chambourcin’ (an interspecific French-American hybrid) is one of the most widely planted winegrape cultivars in the area. It is usually grown as own-rooted (nongrafted) vines because the economic and horticultural benefits of grafting this cultivar to rootstocks have not been well developed. Further, few significant winegrape rootstock evaluations have been conducted in the midwestern United States, including evaluations of newer rootstocks developed and released by private and public breeding programs. The aim of this study was to assess the potential value of using rootstocks in ‘Chambourcin’ production in southern Missouri, with implications for the midwestern United States. Fruit yield, vine growth, and fruit composition metrics from ‘Chambourcin’ on 10 different root systems [own-rooted, and grafted to rootstocks ‘Couderc 3309’, ‘Couderc 1616’, ‘Paulsen 1103’, ‘Sélection Oppenheim 4’, ‘Millardet et de Grasset 420A’, ‘Millardet et de Grasset 101-14’, ‘Kingfisher’, ‘Matador’ (all Vitis sp.), and ‘Gloire de Montpellier’ riverbank grape (Vitis riparia)] in an experimental vineyard in southwest Missouri were compared. Following three establishment years (2008–10), data were collected across four growing and vintage seasons (2011–14). Yield components evaluated included total fruit production, clusters per vine, cluster weight, berry weight, weight of cane prunings, and crop load. Petiole mineral analysis was conducted in 2011, 2013, and 2014. Grape juice attributes measured were soluble solids concentration, juice pH, titratable acidity (TA), potassium (K), anthocyanins, tannins, phenolics, and organic acids. When simply comparing grafted vs. ungrafted vines, grafting generally induced higher plant vigor and a higher pH in the juice, whereas the other parameters did not differ. When the performances were compared among the 10 root systems, vines grafted to ‘Couderc 3309’ had higher yields compared with vines grafted to six other rootstocks and own-rooted vines. Grafting to ‘Millardet et de Grasset 101-14’ induced higher cluster weight compared with the other rootstocks. The ‘Millardet et de Grasset 420A’ rootstock promoted a higher pH and TA as well as a higher concentration of K in the juice, and ‘Paulsen 1103’ also promoted high pH, TA, and malic acid in the juice, and higher concentrations of phosphorous (P) and K in the petiole compared with most rootstocks. ‘Gloire de Montpellier’ induced a lower P content in the petiole and a higher tartaric/malic acid ratio. Rootstock use can strongly influence some vineyard production metrics as well as nutrient uptake and K levels in the juice (the latter further influencing juice pH). The results of this study provide insights into the complex viticultural and enological interactions resulting from the use of rootstocks in hybrid winegrape production in Missouri, USA.

Performance of Hop Cultivars Grown with Artificial Lighting under Subtropical Conditions.

The objective of this study was to determine the duration of the main phenological stages, plant growth development, yield, and cone quality of hop cultivars grown under artificial light (17 h per day) during vegetative development (early season) in a subtropical climate region. The study was conducted in Palotina, Paraná, Brazil (24° S), during the 2021 and 2022 growing seasons. The plants were cultivated in a 5.5 m high trellis system with artificial light supplementation during vegetative development. The hop cultivars Hallertau Mittelfrüher, Mapuche, Northern Brewer, Spalter, and Yakima Gold were used in the treatments. The duration of the phenological stages, vegetative growth (plant height, fresh mass of the plants, number of lateral branches per plant), components of productive yield (number of cones per side branch, number of cones per plant, fresh mass, length, and width of the cone, production of fresh cones per plant, and yield), and chemical components of the cones (alpha- and beta-acid contents, and essential oil concentrations) were recorded. The duration of the phenological stages was visually evaluated, and plant growth was analyzed using non-linear log-logistic regression. The remaining data were subjected to analysis of variance and the means were compared using Tukey's test. The data were also subjected to multivariate analysis using the principal components test, correlation analysis, and hierarchical grouping. The cultivar Mapuche was considered an early hop in both seasons, and the cultivars Spalter and Yakima Gold were considered early cultivars in the second season. In both seasons, the productive yield components were positively correlated with the precocity of the cultivars, in which Mapuche in the 2021 season and Mapuche, Spalter, and Yakima Gold in the 2022 season had the highest mean of the number of cones per side branch and per plant, production per plant, and productivity. The cultivar Yakima Gold had a positive correlation with the chemical quality of cones, alpha and beta acid contents, and essential oil concentrations, for both seasons.

Evapotranspiration and Water Productivity of Microirrigated Wine Grape Vineyards Grown with Different Trellis Systems in the Central Valley of Chile

Evapotranspiration and Water Productivity of Microirrigated Wine Grape Vineyards Grown with Different Trellis Systems in the Central Valley of Chile

Effects of Trellis Systems on the Vegetative Growth and Fruit Quality of Muscat-Flavored Table Grapes

The selection of appropriate grapevine trellis systems is of great importance for regulating vine vigor, forming grape yield, improving fruit quality, and labor-saving field management in the North China Plain. The effects of two trellis systems on the viticultural characteristics and fruit quality of three table grape cultivars: RuiduHongyu (RDHY), RuiduXiangyu (RDXY), and Red Globe (RG) were investigated. The two trellis systems were: (i) T trellis, with shoots positioned horizontally and downwards; and (ii) V trellis, with shoots positioned upright with an inclined angle. Headspace-solid-phase micro-extraction combined with gas chromatography mass spectrometry (HS-SPME-GC-MS) was used to determine the compositions and contents of the monoterpenes in the fruit. The results showed that for RDHY and RG, the T trellis showed better shoot growth consistency. The sugar–acid ratios of RDHY in 2019 and RDXY in 2021 under the T trellis were significantly higher than those under the V trellis. In 2020 and 2021, RDHY showed significantly higher total anthocyanin, flavonoid, and proanthocyanidin concentrations under the T trellis. The total monoterpene content in RDHY berries was significantly higher under the T trellis. The aromatic profiles of RDHY and RDXY grapes were similar and were mainly composed of citrus, other floral, other fruit, and rose aromatic characteristics. Among them, the main aromatic characteristics varied greatly among the different treatments. In conclusion, the Eurasian table grape cultivars with muscat flavor showed a more moderate and controllable vine vigor, consistent shoot growth, better fruit quality and taste, and greater accumulation of polyphenolic compounds and monoterpenes under the T trellis system.

Towards recovery of an endangered Pacific island endemic: Experimental evidence for shortening juvenility of Serianthes plants using a shade and trellis system to generate vigorous growth and precocious flowering

Background and Research Aims Conservationists aiming to establish seed orchards or restoration plantings benefit from methods that reduce tree juvenility. Previous studies suggest that seedling and sapling mortality is the major limitation to natural population recovery of the critically endangered Serianthes nelsonii. To enable effective restoration actions new methods are required to reduce sapling mortality. Methods Ex situ experiments were used to determine if trellised, shaded growth conditions would reduce juvenility of Serianthes saplings. Serianthes kanehirae was used as a surrogate for S. nelsonii. Stem growth was trained horizontally to a wire trellis in shaded tunnels of differing lengths (0, 3, 6, 9 or 12 m). Time to reach the end of each tunnel, and subsequent vertical stem growth in full sun were recorded until flower production commenced. Results The shortest S. kanehirae juvenile phase occurred under 12 m tunnels, with first flower production within a year (351 ± 10 days, mean ± SE). The juvenile phase increased in duration as tunnel length shortened. The control plants did not produce flowers during the study. Conclusion Horizontal trellised support of shaded stems was effective in reducing juvenile phase duration of Serianthes saplings. Implications for Conservation Serianthes seed orchards may use shaded trellises to produce seeds on young plants to rapidly boost species recovery efforts. The production of seeds in managed conservation gardens may improve recovery efforts by reducing the need to remove seeds from in situ communities. Therefore, this simple protocol may prove beneficial for both in situ and ex situ conservation of all federally listed woody plant species in the region.

Micro-CT constitutes a valuable tool in assessing the impact of cordon constriction on the vascular morphology of grapevines

The impact of permanent cordon training systems on the vasculature of grapevines has to date, not been investigated in depth. This study used optical microscopy (stereo microscope) and X-ray microtomography (micro-CT) to quantify the morphological properties of the xylem conduits of cane samples collected from the distal region of cordons, which had been established using four different training techniques. These treatments included one system where the cordon was wrapped very tightly around the cordon wire, a practice that is common in Australia and some other countries. The study also used micro-CT to observe the cordons directly, providing clear insight into the effects of the training methods on the localised structure of the cordons themselves. While the cordons in this study were only four years old at the time of their scanning and 3D reconstruction, significant differences were found between the different training methods. At one of the two trial sites, cordons which were wrapped tightly around the cordon wire had a significantly lower xylem conduit volume in relation to total cordon volume than those which had been woven through a plastic clip system centred between parallel cordon wires. The xylem conduits of woven cordons, in turn, had a lower volume than those which had been trained on top of the cordon wire and secured in place with plastic ties. Cordons which had been wrapped tightly around the cordon wire also had significantly thinner vessels and fewer connections per unit volume between vessels than other treatments at this site, as well as a lower theoretical specific hydraulic conductivity (Ks). No definitive patterns of differences between treatments were observed in the morphological properties of cane samples, either by stereo microscope or micro-CT. The results of this study suggest that the choice of cordon training method may have a notable impact on the capacity of the xylem for normal hydraulic function. Training methods which constrict the vasculature of the cordon, in particular tightly wrapping the cordon around the cordon wire, may have long-term negative outcomes on cordon health and productivity.

Significant increases in Donghong kiwifruit yield by a novel umbrella-shaped trellis system and identification of associated molecular mechanisms.

China is the largest kiwifruit producer in the world, accounting for more than half of the total. However, in terms of yield per unit area, China is much lower than the global average and lags behind that of other countries. Yield improvement is of critical importance for the current kiwifruit industry in China. In this study, an improved overhead pergolas trellis (OPT) system, namely, the umbrella-shaped trellis (UST) system, was developed for Donghong kiwifruit, which is now the second most popular and widely cultivated red-fleshed kiwifruit in China. Surprisingly, the estimated yield on the UST system was more than two times higher than that with a traditional OPT, while the external fruit quality was maintained and the internal fruit quality was improved. One of the mechanisms contributing to the yield improvement was the significant promotion of the vegetative growth of canes at 6 ~ 10mm in diameter by the UST system. The upper canopy of the UST treatment served as a natural shading condition for the lower fruiting canopy and thus had positive effects on the accumulation of chlorophylls and total carotenoids in the fruiting canopy. The most productive zones on the fruiting canes (6 ~ 10mm in diameter) contained significantly higher (P < 0.05) levels of zeatin riboside (ZR) and auxin (IAA) and ratios of ZR/gibberellin (GA), ZR/abscisic acid (ABA), and ABA/GA. A relatively high carbon/nitrogen ratio may promote the flower bud differentiation process of Donghong kiwifruit. The outcomes of this study provide a scientific basis for manifold increase in production of kiwifruit and contribute to the sustainability of the kiwifruit industry.

Viticulture adaptation to global warming: Modelling gas exchange, water status and leaf temperature to probe for practices manipulating water supply, canopy reflectance and radiation load

Associated with climate change, the frequency, duration, and intensity of heatwaves are increasing in most of the key wine regions worldwide. Depending on timing, intensity, and duration, heatwaves can impact grapevine yield and berry composition, with implications for wine quality. To overcome these negative effects, two types of mitigation practices have been proposed (i) to enhance transpiration and (ii) to reduce the radiation load on the canopy. Here we use a biophysical model to quantify the impact of these practices on canopy gas exchange, vine water status, and leaf temperature (Tl). Model validation was performed in a commercial vineyard. Modelled Tl from 14 to 43 °C, and transpiration, from 0.1 to 5.4 mm d−1, aligned around the identity line with measurements in field-grown vines; the RMSD was 2.6 ºC for temperature and 0.96 mm day−1 for transpiration. Trellis system and row orientation modulate Tl. A sprawling single wire trellis with an EW orientation maintained the canopy around 1ºC cooler than a Vertical Shoot Positioned canopy with NS for the same range of total fraction of soil available water (TFAW). Although irrigation before a heatwave is a recommended practice, maximum transpiration can be sustained even when TFAW is reduced, limiting the heat dampening effect of irrigation. Alternatively, canopy cooling can be achieved through Kaolin application, the installation of shade cloth placement, or canopy trimming. Shade cloth produced a greater cooling than Kaolin in all the simulated scenarios; however, Tl differences between them varied. Trimming reduced Tl from 2 ºC to almost 8 ºC compared to its non-trimmed counterpart. Our analysis presents new insights to design heat wave mitigation strategies and supports agronomically meaningful definitions of heat waves that include not only temperature, but also wind, VPD, and radiation load as these factors influence crop physiology under heat stress.

Effective Heat Summation of Grape Cultivars in Response to Phenological Stages in Malatya Ecology

In this study, phenological stages and effective heat summation (EHS) requirements of ten grape cultivars (Banazkara, Köhnü, Kureyş, Tahannebi, Öküzgözü, Ağın Beyazı, Barış, Hatun Parmağı, Italia, and Horoz Karası) grown in Apricot Research Institute Battalgazi Campus Collection Vineyard in Malatya which is one of the important wine growing provinces of Türkiye were determined in the vegetation period of 2021. A double T support system was used and a bilateral cordon training system was formed on the trunk of 80 cm height for the grapevines on the 110 R rootstock by applying a planting density of 3.5 x 2 m in the eight-year-old collection vineyard. For each cultivar, EHS values were recorded with a daily temperature recorder (HOBO) in the stages from the bud break to full bloom, the full bloom to veraison, the veraison to ripening, and from the bud break to maturity. As a result of this study, the EHS values of the cultivars were determined between 1583.5-2113.5 degree days (DD) after the calculation performed by using the average temperature values in Malatya. The lowest EHS requirement was determined as 1583.5 DD in ‘Tahannebi’, while the highest EHS value was determined in ‘Ağın Beyazı’ with 2113.5 DD.

Determining Optimal Levels of Pruning in Hylocereus undatus [(Haw.) Britton and Rose] in Trellis Systems

The main objective of this work was to determine the optimum level of pruning in pitaya. In addition, we want to establish the relationship between pruning levels and the intensity of flowering, and between flowering levels and heavy flower bud drop that affects this species. With these aims, two experiments were performed on Hylocereus undatus [(Haw.) Britton and Rose] cultivated in greenhouses and trained in a trellis system. Our results conclude that cane pruning leaving 15 cladodes per meter in a trellis system is the most productive, as it yielded more fruit of similar weight. Positive relationships between flowering and setting, regardless of pruning levels, justify less severe pruning. Fruit set and size did not depend on pruning levels, although we found a fruit weight reduction when a single cladode developed more than one fruit. Flower buds drop was proportionally higher in cladodes forming more flowers, suggesting that bud competition plays a role in their drop. However, flower bud thinning seems unnecessary, although if a flower is to be chosen, it is better to select those formed at the apex of the cladode since they produce larger fruits.

Effect of Operational Parameters of Unmanned Aerial Vehicle (UAV) on Droplet Deposition in Trellised Pear Orchard

Background: Unmanned Aerial Vehicles (UAVs) are increasingly being used commercially for crop protection in East Asia as a new type of equipment for pesticide applications, which is receiving more and more attention worldwide. A new model of pear cultivation called the ‘Double Primary Branches Along the Row Flat Type’ standard trellised pear orchards (FT orchard) is widely used in China, Japan, Korea, and other Asian countries because it saves manpower and is suitable for mechanization compared to traditional spindle and open-center cultivation. The disease and pest efficacy of the flat-type trellised canopy structure of this cultivation is a great challenge. Therefore, a UAV spraying trial was conducted in an FT orchard, and a four-factor (SV: Spray application volume rate, FS: Flight speed, FH: Flight height, FD: Flight direction) and 3-level orthogonal test were designed. Results: These data were used to analyze the effect, including spray coverage, deposit density, coefficient of variation, and penetration coefficient on the canopy, to determine the optimal operating parameters of the UAV for pest efficacy in FT orchards. The analysis of extremes of variance showed that factor FD had a significant effect on both spray coverage and deposition density. Followed by factor FS, which had a greater effect on spray coverage (p &lt; 0.05), and factor SV, FH, which had a greater effect on deposition density (p &lt; 0.05). The effects of different factors on spray coverage and deposit density were FD &gt; FS &gt; FH &gt; SV, FD &gt; FH &gt; SV &gt; FS, in that order. The SV3-FS1-FH1-FD3, which flight along the row with an application rate of 90 L/ha, a flight speed of 1.5 m/s, and a flight height of 4.5 m, was the optimal combination, which produced the highest deposit density and spray coverage. It was determined through univariate analysis of all experimental groups, using droplet density of 25/cm2 and spray coverage of 1%, and uniformity of 40% as the measurement index, that T4 and T8 performed the best and could meet the control requirements in different horizontal and vertical directions of the pear canopy. The parameters were as follows: flight along the tree rows, application rate not less than 75 L/ha, flight speed no more than 2 m/s, and flight height not higher than 5 m. Conclusion: This article provides ample data to promote innovation in the use of UAVs for crop protection programs in pergola/vertical trellis system orchards such as FT orchards. At the same time, this project provided a comprehensive analysis of canopy deposition methods and associated recommendations for UAV development and applications.

Performance of ‘BRS Magna’ vines grown under different training systems, rootstocks and production cycles

Over the past decade, the business of producing juice from grapes (Vitis labrusca L. and hybrids) has been expanding in response to increasing consumption encouraged by campaigns promoting the benefits grape juice can have on health. This study aimed to determine the effect of the production cycle, vine training system, and rootstock on the yield and physical and physical-chemical characteristics of ‘BRS Magna’ grapes grown in the Vale do Submédio São Francisco in the northeastern region of Brazil. The study was conducted in Petrolina, Pernambuco, over eight production cycles (2017 to 2020). The grapevines were trained in three vine training trellis systems: espalier, lyre, and pergola; and grafted onto two rootstocks: IAC 572 and IAC 766. The production cycle, training system, and rootstocks affected the yield components, vigor, and physical characteristics of the BRS Magna grapes. The combination of the pergola training system and rootstock IAC 766 stood out from the others, providing mean yields estimated at 26 t ha –1 per production cycle. The soluble solids content (SS), titratable acidity (TA), and SS TA –1 ratio were affected neither by the training system nor the rootstock, and higher values for SS and lower values for TA were obtained in the first, second, fourth and eighth production cycles. Thus, the pergola training system and rootstock IAC 766 are recommended for promoting yield gains in the ‘BRS Magna’ grape in the Vale do Submédio São Francisco.

The parameters of vine training systems in Steppe environments can have an impact on vineyard productivity

The parameters of vine training systems in Steppe environments can have an impact on vineyard productivity

Проволочные анкеры и способы их установки

The method of calculation of wire anchors with a conical tip is given. The calculation is based on the condition of static balance of forces: active and reactive. The theoretical foundations of calculating the bearing capacity of wire anchors with a conical tip are given. The variants of practical application of wire anchors on mountain and foothill landscapes, in construction, in agriculture in the construction of trellis systems and other industries are described. Various options for installing wire anchors are given. The method of installation using vibratory hammers and impact hammers, which can be used when installing wire anchors on chips, is described in detail. When installing wire anchors with a conical tip, it is stretched into a guide rod, which is embedded in the ground with the help of vibratory hammers, by the operator. After installing the wire anchor to the required depth, the guide rod is removed. When installing a wire anchor with a hammer, the operator, lifting it, hits the lower impact device rigidly fixed to the guide rod. Other lever devices for installing wire anchors are described. All innovative developments are patented in the Russian Federation.

White Cane-Type Holdable Device Using Illusory Pulling Cues for Orientation &amp; Mobility Training

For visually impaired people, a white cane is an important aid for obtaining information about the surrounding environment. Although the visually impaired should attend this training by orientation & mobility (O&M) specialists to learn proper cane technique, the number of specialists is limited. In our previous study, we developed a training system that enabled the visually impaired to learn white cane techniques using illusory pulling cues. In the previous prototype system, a cane grip-type device was developed with a built-in vibrator to generate asymmetric vibration stimuli, and illusory pulling cues were fed according to the position of the cane tip. Although the prototype system showed positive results, issues related to the lack of user-friendliness of the device associated with the wired drive and the impractical gripping method were observed. This study developed a more practical white-cane-type device for O&M training, envisioning independent training for the visually impaired, which improved the above-mentioned issues. Specifically, the device was wireless and had a vibration mechanism for the gripping method of the general cane technique, and its validity was demonstrated by evaluation experiments. In addition, the paper explains the usefulness of the device as per discussion with active O&M specialists. The results of the evaluation experiments indicated that the devices were implemented to satisfy the requirements for cane training.

Responses of grapevines to planting density and training systems in semiarid environments

Aim. To investigate the physiological and agrobiological responses of grapevines on different systems of training systems in row plantations depending on the planting density and the possibility of adjusting plants for non-irri- gated crop cultivation under cold semiarid climate. Methods. The field two-way experiment of 2 × 4 was applied to study the effect of two planting density variants (3 × 1.5 m; 3 × 1 m) and four vine training systems (when the horizontal cordon is located at the height of 0.4 m, 0.8 m, 1.2 m, 1.6 m) on the parameters of the leaf area, leaf index, water loss through transpiration, activity of the photosynthetic apparatus of leaves and the yield of Zahrei wine grape cultivar (Vitis vinifera L.). The experiment data were processed using the analysis of variance. Results. The increase in the density of vine row plantations per area units from 3 × 1.5 m to 3 × 1 m enlarges the total leaf area, the exposed leaf area, water loss through transpiration, and yield weight, but these indices decrease in the evaluations per plant. The responses of grapevine to the training systems are similar and independent from the ex- perimental variants of planting density. At the height of the cordon of 0.4 and 0.8 m, the vertical shoot positioning enhances the potential of the photosynthetic capacity of the plantations, but this potential is realized only during the years with lower water deficit for plants. Free-growing shootings on the cordons, located at the height of 1.2 m, form the canopy architecture with relatively low water loss through transpiration which has a positive effect on the activity of the photosynthetic apparatus and yield, especially in dry years. The downward shoot positioning on the cordons of 1.6 m decreases the leaf area of the vines and creates the canopy architecture with increased transpiration which enhances the effect of the water deficit and has a negative effect on the productivity of plants. Conclusions. The agronomic methods of planting and training systems for grapevines ensure the management of the character of spatial shoot location, the formation of certain canopy architecture, and setting the parameters of the leaf area; their optimization mitigates the negative effect of water deficit and provides for adapting the plants for non-irrigated crops under semiarid climate. The positive effect of compacting plantations on crop yield was determined without irrigation in semiarid environments. The variant of planting density of 3 × 1 m decreases the yield on the vines on average by 12.1–31.0 %, as compared to the variant of 3 × 1.5 m. Yet, more dense plantations are remarkable for their yield, which is 18.5–61.3 % higher depending on the training system for vines. Under dry conditions, the most efficient system is the training system with the formation of the horizontal cordon at the height of 1.2 m and free-growing shoots. The system optimizes the leaf area density, and forms the canopy architecture with rather low water loss through transpiration which has a positive effect on the activity of the photosynthetic apparatus of leaves during droughts. Under free growth, the yield of the plantations increases by 4.3–12.3 % on average as compared to the vertical shoot positioning and by 21.3 % – under their downward positioning.