Berry Set Research Articles

Exploring grapevine canopy management: effects of removing main leaves or lateral shoots before flowering

Over the course of a six-year trial, we investigated the physiological response of the Swiss white cultivar Vitis vinifera Petite Arvine, rich in varietal thiols, to the following canopy removal treatments from the cluster area, i.e. from the shoot base to the sixth leaf of each shoot: A) lateral shoots only, B) lateral shoots + 50 % main leaves, C) lateral shoots + 100 % main leaves or D) main leaves only. All leaf removal (LR) treatments were performed at the pre-flowering stage. Intensive pre-flowering removal of both lateral shoots + 100 % main leaves from the cluster area (C) strongly reduced yield potential (‒47 % on average) and tended to reduce the concentration of 3-mercaptohexanol precursors (Cys-3MH) in the must (‒21 %; p-value < 0.10). The effect of LR on berry set and must composition was modulated by removing fewer main leaves (‒24 % in yield potential and ‒6 % in Cys-3MH concentration). Climate conditions primarily influenced yield and grape composition. Main leaves and lateral shoots played different physiological roles: removal of main leaves only (D) resulted in a larger leaf area (+15 %) due to the development of lateral shoots in the cluster area and a lower yield potential (‒12 %) due to fewer berries per cluster when compared one-to-one with removal of lateral shoots only (A). In the must at harvest, treatment D had higher concentrations of malic acid (+12 %), yeast-assimilable nitrogen (+10 %) and glutathione (+8 %), but there were no significant trends for TSS, pH, Cys-3MH or Folin index. The overall effects of pre-flowering LR on wine composition were negligible in the context of this trial. The study highlighted the different physiological roles of the main leaves and lateral shoots, suggesting that pre-flowering leaf removal should be used cautiously, taking into account the plant’s resilience to environmental conditions. This research is part of a broader project on grapevine canopy management in temperate climates in Switzerland.

Pollen biology and metaxenic studies on early maturing grape (Vitis vinifera) genotypes

The present experiment was conducted during 2020–21 and 2021–22 at ICAR-Indian Agricultural Research Institute, New Delhi to study the impact of open-, self-, and cross-pollination on metaxenic traits (berries) and the incidence of cleistogamy in grapes (Vitis vinifera L.). Seven different cross-combinations were used on the grape variety Pusa Navrang, which were planted at 3 m × 3 m spacing and trained on the Y-trellis training system. The experiment was laid out in a randomized block design (RBD) with four replications. The incidence of cleistogamy, berry set, retention percentage, and the metaxenia effect of pollen grains in different grapevine varieties, namely, Pusa Navrang (PN), Black Muscat (BM), Pusa Swarnika (PS), Beauty Seedless (BS), Perlette (PER), Male Hybrid (MH), were studied. Also, pollen quantity and viability were determined for the different grapevine varieties under study. Depending on the genotypes and whether the fruit set is obtained inside the covered flowers, cleistogamy was confirmed. A significantly higher berry set (40–85%) and retention (32–77%) were recorded in open- and self-pollinated flowers. The total number of pollens/anther in six grape genotypes ranged from 7916.62–23832.02, whereas the maximum active pollen rates were noted in the Male Hybrid (70.01%) and Black Muscat (66.80%). The pollens from the Beauty Seedless genotype exhibited significant enhancement of metaxenic traits such as berry set, retention, and size in Pusa Navrang. Therefore, utilizing Beauty Seedless as a pollen parent in grape breeding programmes holds promise for enhancing berry set and overall berry quality, thus enhancing the hybridization efficiency.

Vitis rotundifolia Genes Introgressed with RUN1 and RPV1: Poor Recombination and Impact on V. vinifera Berry Transcriptome.

Thanks to several Vitis vinifera backcrosses with an initial V. vinifera L. × V. rotundifolia (previously Muscadinia rotundifolia) interspecific cross, the MrRUN1/MrRPV1 locus (resistance to downy and powdery mildews) was introgressed in genotypes phenotypically close to V. vinifera varieties. To check the consequences of introgressing parts of the V. rotundifolia genome on gene expression during fruit development, we conducted a comparative RNA-seq study on single berries from different V. vinifera cultivars and V. vinifera × V. rotundifolia hybrids, including 'G5' and two derivative microvine lines, 'MV102' (resistant) and 'MV32' (susceptible) segregating for the MrRUN1/RPV1 locus. RNA-Seq profiles were analyzed on a comprehensive set of single berries from the end of the herbaceous plateau to the ripe stage. Pair-end reads were aligned both on V. vinifera PN40024.V4 reference genome, V. rotundifolia cv 'Trayshed' and cv 'Carlos', and to the few resistance genes from the original V. rotundifolia cv '52' parent available at NCBI. Weighted Gene Co-expression Network Analysis (WGCNA) led to classifying the differentially expressed genes into 15 modules either preferentially correlated with resistance or berry phenology and composition. Resistance positively correlated transcripts predominantly mapped on the 4-5 Mb distal region of V. rotundifolia chromosome 12 beginning with the MrRUN1/MrRPV1 locus, while the negatively correlated ones mapped on the orthologous V. vinifera region, showing this large extremity of LG12 remained recalcitrant to internal recombination during the successive backcrosses. Some constitutively expressed V. rotundifolia genes were also observed at lower densities outside this region. Genes overexpressed in developing berries from resistant accessions, either introgressed from V. rotundifolia or triggered by these in the vinifera genome, spanned various functional groups, encompassing calcium signal transduction, hormone signaling, transcription factors, plant-pathogen-associated interactions, disease resistance proteins, ROS and phenylpropanoid biosynthesis. This transcriptomic insight provides a foundation for understanding the disease resistance inherent in these hybrid cultivars and suggests a constitutive expression of NIR NBS LRR triggering calcium signaling. Moreover, these results illustrate the magnitude of transcriptomic changes caused by the introgressed V. rotundifolia background in backcrossed hybrids, on a large number of functions largely exceeding the ones constitutively expressed in single resistant gene transformants.

Identification, Elucidation and Deployment of a Cytoplasmic Male Sterility System for Hybrid Potato.

Recent advances in diploid F1 hybrid potato breeding rely on the production of inbred lines using the S-locus inhibitor (Sli) gene. As a result of this method, female parent lines are self-fertile and require emasculation before hybrid seed production. The resulting F1 hybrids are self-fertile as well and produce many undesirable berries in the field. Utilization of cytoplasmic male sterility would eliminate the need for emasculation, resulting in more efficient hybrid seed production and male sterile F1 hybrids. We observed plants that completely lacked anthers in an F2 population derived from an interspecific cross between diploid S. tuberosum and S. microdontum. We studied the antherless trait to determine its suitability for use in hybrid potato breeding. We mapped the causal locus to the short arm of Chromosome 6, developed KASP markers for the antherless (al) locus and introduced it into lines with T and A cytoplasm. We found that antherless type male sterility is not expressed in T and A cytoplasm, proving that it is a form of CMS. We hybridized male sterile al/al plants with P cytoplasm with pollen from al/al plants with T and A cytoplasm and we show that the resulting hybrids set significantly fewer berries in the field. Here, we show that the antherless CMS system can be readily deployed in diploid F1 hybrid potato breeding to improve hybridization efficiency and reduce berry set in the field.

Defoliation at berry set alters grape composition and gene expression during berry development in two Greek <i>Vitis vinifera</i> L. cultivars

The quality traits of a given grapevine cultivar are determined by the combinatorial action of the genotype, and environmental factors such as soil, landscape, and climate. Nonetheless, another critical factor is vineyard management. The forthcoming effects of climate change on viticulture represent a challenge for the application of sustainable practices. The impact of leaf removal at berry set stage on the Greek Vitis vinifera L. cultivars ‘Agiorgitiko’ and ‘Assyrtiko’ (a red- and white-berry cultivar, respectively) was investigated during the 2019 and 2020 vintages. Vine physiology measurements and berry sampling were performed at three phenological stages: green berry, veraison and harvest. Grape berry composition and the expression level of specific genes were analysed during ripening. Defoliation decreased berry weight in Assyrtiko, while no significant effect was observed in Agiorgitiko. The treatment resulted in a significant increase in total soluble solids and reduced acidity compared to the controls in both cultivars, while the effect on total phenols mainly depended on climate conditions. The expression profile of the genes examined was also altered during ripening, whereas the response to defoliation mainly depended on the vintage and the cultivar. Taken together, the results suggest that defoliation is a useful technique for maintaining grape and wine quality.

Seed and Germination Characteristics of Different Hybrids Belonging to Vitis Species

In this research, some grape cultivars are belonging to Vitis vinifera, Vitis labrusca, and interspecific grape cultivars were used for crossbreeding. The aim of the cross-breedings was to obtain individuals that could be used as a table grape, female flower type genotypes, and would be resistant to disease and cold hardy grapes. In the research, berry set (seeded and seedless berry number), seed weight (g), seed width and length (mm), floating empty seed rate (seed viability, %), seed germination rates (%), seedling survival rates (%) and shoot length (cm) were calculated in the seeds obtained as a result of cross-breeding. In this research, as a result of crossbreeding with different Vitis species and hybrids, the germination rate was significantly higher, especially when using ‘Red Globe’ and ‘Cayuga White’ cultivars as maternal parents. Although the germination rates of the seeds obtained after cross-breeding are low, the use of ‘Çavuş’ grape cultivar with female flower form in cross-breeding facilitates the work since emasculation is not necessary. It would be appropriate to increase the number of grapevines with female flowers type in breeding studies.

Improvement in Physiochemical Characteristics of ‘Prime Seedless’ Grapes by Basal Defoliation with Foliar-Sprayed Low-Biuret Urea and Cyanocobalamin under Mediterranean Climate

In viticulture, the main target is to achieve high yield and good fruit quality without compromising vine growth. Methods to achieve this balance will vary with regard to climate and cultivar. A two-year study was conducted on five-year-old ‘Prime Seedless’ grapevines to evaluate the effect of leaf defoliation and the foliar application of low-biuret urea (LBU) and cyanocobalamin (CCA) on berry set percentage, the compactness coefficient of the clusters and the overall quality of clusters and berries. The removal of the first four basal leaves was conducted at the full-bloom (FB) stage, while LBU (5 g·L−1) and CCA (40 mg·L−1) were sprayed at three phenological stages: (1) when the cluster length reached ~10 cm long, (2) at FB and (3) one week after the fruit set. The results demonstrated that the sole application of basal leaf removal (BLR) or in combination with LBU and/or CCA improved the vegetative growth, total yield and physiochemical characteristics of clusters and berries, whereas the same treatments decreased berry set and shot berry percentages and the compactness coefficient of the clusters, which in turn led to looser clusters compared to the control. The most pronounced effect was recorded for the combined application of BLR, LBU and CCA, which revealed the highest values of shoot length, leaf area and the contents of chlorophyll, proline, N, P, K, Ca, Mg, Fe and Zn. The same treatment recorded the lowest berry set and shot berry percentages, compactness coefficient of clusters and decay percentage. Overall, this treatment was the best in terms of total yield, cluster weight, berry firmness, soluble solid content (SSC), the SSC/acid ratio, total sugars, total carotenoids, total phenols, phenylalanine ammonialyase and polyphenol oxidase.

Optimizing ‘Xinomavro’ (Vitis vinifera L.) Performance by Post-Bloom Basal Leaf Removal Applications

A three-year study was conducted to investigate the effects of two timings—at berry set and at veraison—of post-bloom leaf removal (LR) applications from the basal sections of the shoot on the growth, yield, and berry composition of Vitis vinifera L. cv. Xinomavro, the major red winegrape of North Greece. LR at berry set drastically reduced yield by affecting all its components while increasing the ratio of secondary foliage per total leaf area. LR at veraison had a milder effect on growth and yield. Both treatments increased sugar and phenolic compound levels in berries, while early LR increased the contribution of more stable forms of anthocyanins. Additionally, early LR increased the skin-to-pulp ratio, suggesting that it could be an effective viticultural technique for more concentrated red wines. Overall, both LR timings improved most of the berry attributes compared to the non-treated vines; however, the earlier application can be recommended when aiming at the production of deep-colored and richly flavored wines.

Enhancing Uniform Sprouting, Yield, and Quality in Grapevines: The Impact of Hydrogen Cyanamide (50% S.L) Treatment

Grape (Vitis vinifera L.) is considered as one of the most important commercial fruit crops in temperate, tropical and subtropical regions of the world. In India grape cultivation in tropical and subtropical regions assumes great significance, but one of the biggest issues preventing grapes from being produced in warm climates has been the lack of or insufficient winter chilling. Under these circumstances, there is uneven bud bursting, flowering, and delayed fruit development. The most crucial component of grape development is, consistent bud breaking is required to increase grape quality and maturity. Many plant growth regulators are used to promote bud burst and increase the proportion of bud break. Several locations across the world utilize plant growth regulators to intentionally cause bud break. The application of Hydrogen Cyanamide (H2CN2) during pruning time of grapes, helps to enhance growth uniformity, encourage earlier and more even bud break, raises the proportion of fruit buds, berry set, number of clusters per vine, weight of clusters, and dimensions of clusters. It also gives positive response to various metabolic activities; maximize yield and Maturity, Fruit quality, as well as production efficiency. In grape orchards, it is commonly used to promote consistent and improved bud burst, shortened flowering period, and boost output.

A Preliminary Method for Tracking In-Season Grapevine Cluster Closure Using Image Segmentation and Image Thresholding

Mapping and monitoring cluster morphology provides insights for disease risk assessment, quality control in wine production, and understanding environmental influences on cluster shape. During the progression of grapevine morphology, cluster closure (CC) (also called bunch closure) is the stage when berries touch one another. This study used mobile phone images to develop a direct quantification method for tracking CC in three grapevine cultivars (Riesling, Pinot gris, and Cabernet Franc). A total of 809 cluster images from fruit set to veraison were analyzed using two image segmentation methods: (i) a Pyramid Scene Parsing Network (PSPNet) to extract cluster boundaries and (ii) Otsu’s image thresholding method to calculate % CC based on gaps between the berries. PSPNet produced high accuracy (mean accuracy = 0.98, mean intersection over union (mIoU) = 0.95) with mIoU > 0.90 for both cluster and noncluster classes. Otsu’s thresholding method resulted in <2% falsely classified gap and berry pixels affecting quantified % CC. The progression of CC was described using basic statistics (mean and standard deviation) and using a curve fit. The CC curve showed an asymptotic trend, with a higher rate of progression observed in the first three weeks, followed by a gradual approach towards an asymptote. We propose that the X value (in this example, number of weeks past berry set) at which the CC progression curve reaches the asymptote be considered as the official phenological stage of CC. The developed method provides a continuous scale of CC throughout the season, potentially serving as a valuable open-source research tool for studying grapevine cluster phenology and factors affecting CC.

Flower-Visiting Insects Ensure Coffee Yield and Quality

(1) Background: The participation of insects in the pollination of self-pollinating plants, such as coffee, is still controversial. This study determined the effect of flower-visiting insects on coffee berry set, yield, and quality. (2) Methods: Over 2 years, five evaluations in different locations, dates, and harvest times were carried out. Each evaluation consisted of eight treatments with 50 replicates each, arranged in a completely randomized experimental design. Treatments were established to identify the contribution of insects, wind, gravity, self-pollination, and cross-pollination to coffee yield and quality. (3) Results: The insects contributed 16.3% of the berry set, 26.9% of the berry coffee yield, and 30.6% of the weight of supremo-type beans. No differences were observed in the sensory quality of coffee produced with or without insects. For stigma receptivity, results indicate that there is a 6.3% probability of self-pollination during pre-anthesis. (4) Conclusions: The species Coffea arabica, despite being a self-pollinating plant, benefits from the presence of flower-visiting insects. During anthesis, arabica coffee flowers are ready for cross-pollination.

Exploring key physiological attributes of grapevine cultivars under the influence of seasonal environmental variability

Seasonal climatic variability is a key challenge in many grape-growing regions across the globe, affecting phenology, growth, physiological responses, and yield at harvest. Unfavourable climatic conditions impair the plant's physiological processes, such as chlorophyll accumulation, gas exchange and photosynthesis in grapevine leaves. It is critical to unlock the complex physiological behaviour of grapevine cultivars at key phenological stages and under varying environmental conditions. The present study was designed to evaluate the key physiological processes, such as gas exchange, chlorophyll contents and water use efficiency (WUE), of four table grape cultivars at key growth stages under varying environmental conditions of the Pothwar region, in a factorial experimental set up (Location× Year × Cultivar × Phenological stage). The physiological responses of the table grape cultivars were recorded at the 5-leaf stage, full bloom, berry set, veraison and harvest during two consecutive vintages (2019 and 2020) in two locations (Islamabad and Chakwal). The results show that the mean photosynthetic activity in colder Islamabad was 30.7 % higher than in Chakwal, and the transpiration rate and WUE were 10.4 % and 28.6 % higher. Similarly, 12 % higher photosynthetic activity, with 13 % more WUE, was observed in the colder vintage of 2020 compared to that of 2019. The vine physiological activity also varied among cultivars; for example, cv. Sugraone was found to have 12 % more chlorophyll and 30 % higher photosynthetic activity than cv. Kings Ruby. Similarly, higher photosynthetic activity and transpiration rates were recorded at the berry set stage, while WUE peaked near blooming. The biplot analysis for the first two principal components also showed cv. Sugraone to be a highly responsive and physiologically efficient cultivar. The findings of the present research will help to better assess the effect of seasonal variability on vine physiological performance and to identify genotypes with higher photosynthetic potential and WUE. It could also assist in devising vineyard management strategies to better adapt to varying environmental conditions.

Mechanisation of pre-flowering leaf removal under the temperate climate conditions of Switzerland

The present trial follows a previous study about pre-flowering leaf removal (LR) (Verdenal et al., 2019) and validates the sustainability of mechanical pre-flowering LR under local Swiss vineyard conditions, using a low-pressure double airflow, to reduce the cost of laborious bunch thinning. In previous studies, pre-flowering LR has shown additional benefits over post-berry-set LR in terms of yield regulation and grape and wine compositions. This trial had two objectives: 1) to test the technical feasibility of mechanical pre-flowering LR, using a low-pressure double airflow and 2) to observe the impact of this practice over five years on yield parameters, grape composition at harvest and wine quality over five years. For this purpose, a trial was conducted on the two cultivars, Doral (white) and Gamay (red), to compare four LR treatments, that is, A) mechanical post-berry-set LR, B) manual pre-flowering LR, C) mechanical pre-flowering LR, and D) double mechanical pre-flowering + post-berry-set LR. More broadly, this work provides practical insights into the consequences of pre-flowering LR on the grapevine, pointing out the advantages and the limits of intensity, timing and mechanisation of this practice. In comparison with the mechanical post-berry-set LR, mechanical pre-flowering LR induced a 7 % loss in bud fruitfulness, a 30 % yield loss and a 3 % gain in total soluble solids (TSS) accumulation in grapes in both cultivars, although the improvement in grape maturity was small and uneven through the years; Gamay anthocyanin concentration remained stable. Pre-flowering LR had no overall impact on the quality of Doral and Gamay wines. Damage was observed on the inflorescences due to the intensity of mechanical pre-flowering LR, which resulted in fewer berries per cluster and a lower yield than with manual LR by the same date. A second LR after berry set was also tested to limit the growth of laterals and clean the clusters from the remaining flower caps to prevent the development of fungal diseases, but it did not show any benefit over a single pre-flowering LR. In conclusion of this trial, a single, moderate mechanical pre-flowering LR is an effective and sustainable practice under temperate climatic conditions, to reduce the costs of laborious manual pre-flowering LR.

Değişik Gelişme Dönemlerinde Yapılan Yaprak Alma ve Uç Alma Uygulamalarının Asma Yaprak Alanı Özelliklerine Etkisi

Bu araştırma; Trakya’da, 41° 01'11.41" K ve 27°39'49.14" D enlem ve boylamlarında Michele Palieri üzüm çeşidi bağında yürütülmüştür. Omcalara farklı yaprak alma - uç alma uygulamaları farklı fenolojik gelişme aşamalarında uygulanmış ve bunların yaprak özelliklerine etkisi araştırılmıştır. Deneme 2018-2019 ve 2019-2020 gelişme periyotlarında yürütülmüştür. Denemede 3 değişik gelişme döneminde (Tane Tutumu, İri Koruk, Ben Düşme) ve 4 farklı uygulama (Kontrol, Uç Alma, Yaprak Alma ve Yaprak Alma+Uç Alma) yapılmıştır. Yaprak alanı özelliklerini belirlemek için; fenolojik gelişme aşamaları, ortalama ana yaprak ve koltuk yaprak alanı (cm2), omca başına ana yaprak ve koltuk yaprak alanı (cm2 omca-1), omca başına toplam yaprak alanı (cm2 omca-1), dekara verim (kg da-1), bir kilogram üzüme düşen gerçek yaprak alanı (cm2 kg-1) doğrudan güneş gören yaprak alanı (m2 da-1) ve bir kilogram üzüme düşen güneş gören yaprak alanı (cm2 kg-1) hesaplamaları yapılmıştır. Sonuç olarak; Tekirdağ ilinde Michele Palieri sofralık üzüm çeşidinde İri Koruk döneminde gerçekleştirilen Yaprak Alma ve Yaprak Alma+Uç Alma uygulamalarının yaprak alanlarını artırdığı belirlenmiştir.

Seasonal variability in the effect of temperature on key phenological stages of four table grapes cultivars.

Progressive warming of the grape growing regions has reduced the land capability for sustainable grapevine production and the geographical distribution of grapes. Bud burst, blooming, berry set, veraison, and harvest are the key phenological stages of grapevine, and are crucial for managing vineyard activities. The objective of this study was to evaluate the effect of seasonal temperature variability on the timing of key phenological stages of table grape cultivars in a new emerging viticulture region, i.e., the Pothwar region of Pakistan. Phenological stages of four table grape cultivars were recorded during two consecutive growing seasons at two locations. All phenological stages were attained earlier for the relatively warmer location, i.e., Chakwal. Similarly, the length of the growing season from bud burst to harvest was 15 to 21days longer for the 2020 growing season than for the 2019 growing season, which corresponds to the inter-annual temperature variability. Moreover, the grapevine cultivars showed a distinct response for each growth phase; cv. Perlette matured earlier while cv. NARC Black was the last to ripen. Despite the large variability in the length of the active growing period from bud burst to harvest, accumulated growing degree days (GDD) varied only in a narrow range, i.e., 1510-1557 for cv. Perlette, 1641-1683 for cv. King's Ruby, 1744-1770 for cv. Sugraone, and 1869-1906 for cv. NARC Black. This implies that seasonal temperature variability using GDD is a better indicator for the phenology of table grape cultivars compared to regular time. It is clear from the results from this study that the variation in phenological responses of table grape cultivars due to temperature differences necessitates genotype and site-specific vineyard management.

Effect of Bio-stimulant Application on Growth, Yield and Quality of Thompson Seedless

Bio-stimulants offers a novel approach to enhance crop growth, quality and ultimately final yield of the produce. Nowadays, bio-stimulants containing Ascophyllum nodosum seaweed extracts and protein hydrolysates are increasing interest of scientists and farming communities. However, the potential of many of these bio stimulants products has not been fully exploited in grapes due to the lack of available scientific data. Grape growing under tropical conditions of India faces various type abiotic and biotic stresses. To support grapevine growth as well as yield and quality, bio-stimulant application can play an important role. Present experimentation was conducted at the farm of ICAR-National Research Centre for Grapes, Pune during the year 2020-21 with the objective to assess the effects of bio-stimulant application on growth, yield and quality of Thompson Seedless grapes. Different doses of bio-stimulant were applied on vines at different crop growth stages such as 3-4 leaf stage, pre-bloom stage and after berry setting, followed by two bunch dipping with varied concentrations. Among the different treatments T7 [RDF + 1.5 % (Spray: 3rd) + 0.2 % Bunch dipping (Stage 1) + 0.5 % Bunch dipping (stage 2)] found better in terms of bunch and berry quality parameters. Obtained results suggested that the application of bio-stimulant (Grade-I) affects vine growth, yield and quality of the Thompson Seedless grape in positive manner.

Morpho-biological features of growth and development of golden currant in Tashkent province, Uzbekistan

This scientific article presents the results of a study on the growth and development of varieties of golden currant in order to identify the most promising for cultivation in the conditions of the Tashkent region. Studies have established that, according to the development of shoots in the above-ground part, the varieties Uzbekistanskaya large-fruited and Elixir differ in vigorous growth, in which the height of the bushes by the end of the second year of vegetation reached 109.7-112.5, and in other varieties this figure was in the range of 88.2-97.5 cm. Of the tested varieties of golden currant, the earliest onset of the flowering phase was observed in the Venera variety March 23, in the rest a little later. The variety of golden currant Rukhshona had the latest start of flowering, in which this phase occurred on March 26, that is, four days later. In the Uzbekistan large-fruited variety, the completion of the flowering phase occurred five days later than in the Uzbek sweet variety. Of the varieties of golden currant, the phase of complete set of berries was observed most intensively within 30 days in the variety Venera. In the Elixir variety, the full set of berries ended two days later, and in the rest within 34-36 days.

АНАЛИЗ ПРОВЕДЕНИЯ ВОДНЫХ МЕЛИОРАЦИЙ НА ВИНОГРАДНИКАХ В РОССИИ

Purpose: to analyze the scientists’ studies on terms, methods and norms of irrigation of vineyards to identify the optimal conditions for irrigation in the Republic of Crimea. Discussion. An overview of research papers from domestic and foreign sources concerning various terms, methods and rates for irrigating vineyards is presented. It is almost impossible to obtain high yields of good quality when growing grapes in the zone of unstable moisture, but it is also not recommended to irrigate uncontrollably, since excessive humidity during critical periods leads to a decrease in the set of berries and to their cracking, which affects the quality of the harvest. The correct application of modes and methods of irrigation is one of the main tasks of viticulture. The options for using various terms, methods and irrigation rates for irrigating vineyards in order to obtain good quality grape products in the required quantity are discussed. Also here the optimal ways of irrigating vineyards under the conditions of the Republic of Crimea are presented. Conclusions. The analysis of various studies devoted to the study of terms, methods and rates of vineyard irrigation made it possible to establish the optimal irrigation regime for vineyards and to identify the most suitable irrigation method for vineyards. Based on the results of research conducted by scientists and taking into account the agro-climatic conditions of the Republic of Crimea, a drip method for irrigating vineyards while maintaining soil moisture not lower than 80 % of the lowest moisture capacity in a layer of 0.8 m is proposed.

Comparative Analysis of Grapevine Epiphytic Microbiomes among Different Varieties, Tissues, and Developmental Stages in the Same Terroir

There is limited knowledge about the relationships of epiphytic microbiomes associated with the phyllosphere of different Vitis vinifera cultivars in the same vineyard and terroir. To address this research gap, we investigated the microbiome compositionof 36 grapevine genotypes grown in the same vineyard in different plant sections during the growing season. Using high-throughput NGS-based metagenomic analysis targeting the ITS2 and the V4 regions of the 16S ribosomal gene of fungal and bacterial communities, respectively, weassessed the impact of grapevine genotypes on microbial assemblages in various parts of the phyllosphere. The results indicated that different phyllosphere tissues display high microbial diversity regardless of the cultivars’ identity and use. The selected three phyllosphere parts representing three distinct phenological stages, namely bark and bud, berry set, and fruit harvest, had almost a similar number of fungal OTUs, while a difference was recorded for the bacterial species. The fruit harvest stage hosted the highest number of bacterial OTUs, whereas the bark and bud stage contained the lower. Bacterial dominant phyla were Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes, and the genera were Gluconacetobacter, Erwinia, Gluconobacter, Zymobacter, Buchnera, Pseudomonas, Pantoea, Hymenobacter, Pedobacter, Frigoribacterium, Sphingomonas, and Massilia. For fungi, the dominant phyla were Ascomycota and Basidiomycota, and the genera were Aureobasidium, Cladosporium, Alternaria, Aspergillus, Davidiella, Phoma, Epicoccum, Rhodosporidium, Glomerella, Botryosphaeria, Metschnikowia, Issatchenkia, and Lewia. Both the genotype of the cultivar and the phenological stage appeared to considerably impact the shape of microbial diversity and structure within the same terroir. Taken together, these results indicate that microbiome analysis could be proved to be an important molecular fingerprint of cultivars and provide an efficient management tool for the traceability of wine and grape end products. Moreover, the unique identity of cultivars’ microbial signatures highlights the need for further development of precision management to support viticulture sustainability in the face of climate change.

Growth-Development, Yield and Quality Characteristics of Aronia Varieties Grown in Pots

This study was carried out to determine the growth, development, yield and some quality characteristics of Nero and Viking Aronia varieties grown in open field and pot in Samsun ecological conditions. Three-year-old Aronia plants were planted in 80-liter pots containing a 1:1:1 (v/v) mixture (barnyard manure+soil+sand) and 5 plants were included in each replication. Number of shoots, flower buds and clusters, berry weight (g), yield (g/plant), firmness (N), number of fruits per cluster, must yield (ml/100g), TSSS (%) and pH values were measured in Aronia cultivars. In addition, monthly shoot growth rate (cm/month) was determined and phenological observations recorded. According to Viking and Nero Aronia varieties, the number of shoots (7.8 and 7.6 pieces), the number of flower buds (22.63 and 22.85 pieces), the number of clusters (45.06 and 44.80 pieces), the weight of berry (0.82 and 0.79 g), the fruit number in the bunch (21.45 and 21.53 pieces), berry firmness (4.90 and 5.35 N), amount of must (49.67 and 54.00 ml/100 g) and TSS (17.07 and 16.47) and pH values (3.65 and 3.52) were found to be close to each other. Bud burst (10 March), flowering (26 April), berry set (12 May) and harvest time (24 August) were also similar in cultivars. It was also revealed that while the shoot length was 97.47 cm and 95.47 cm on March 11, respectively, in Viking and Nero varieties, it reached 124.73 and 120.73 cm in August, five months later.