Berry Thinning Research Articles

Study on Quality of Verjuice Affected by Grape Types, Treatments and Storage at Ambient Conditions

To improve the quality of grape berries and bunches, berry thinning is adopted. In this practice, a sizeable quantity of thinned berries is destroyed despite having valuable contents. Thinned berries are utilized to produce verjuice in different countries. To assess the effect of grape varieties and ingredients on verjuice quality, the present study was conducted at ICAR-National Research Centre for Grapes, Pune during the fruiting season of 2022-2023. Thinned grape berries (6-8 mm diameter) from four varieties namely Manjari Naveen, Crimson Seedless, Thompson Seedless and Manjari Kishmish were utilized with three treatments as the addition of 0.49 g NaCl salt/100 mL, 3 mL olive oil/100 mL and combination of 0.49 g NaCl salt and 3 mL olive oil/100 mL. Physico-chemical parameters of prepared verjuice types were observed initially as well as 15, 30 and 45 days of storage at ambient conditions. At the initial stage, among the varieties, treatments and their interactions showed non-significant differences for TSS, acidity and pH. Among the different verjuice types, except Crimson Seedless with salt and olive oil, were recorded with maximum TSS. The pH values Were ranged from 2.35 to 2.57 while the maximum recorded titratable acidity was 3.07% whereas the lowest acidity was 2.43%. Verjuice storage at ambient conditions resulted in reduced TSS, acidity and pH. Verjuice prepared from Manjari Kishmish showed superiority in all sensory parameters while verjuice from Thompson Seedless was scored minimum. Results recorded in the present study revealed that the quality of verjuice was acceptable and need to study the combinations of different type grapes to improve verjuice quality and pesticide degradation in the process.

3D grape bunch model reconstruction from 2D images

A crucial step in the production of table grapes is berry thinning. This is because the market value of table grape production is significantly influenced by bunch compactness, bunch form and berry size, all of which are primarily regulated by this task. Grape farmers must count the number of berries in the working bunch and decide which berry should be eliminated during thinning, a process requiring extensive viticultural knowledge. However, the use of 2D pictures for automatic berry counting and identifying the berries to be removed has limitations, as the number of visible berries might vary greatly depending on the direction of view. In addition, it is extremely important to understand the 3D structure of a bunch when considering future automation via robotics. For the reasons stated, obtaining a field-applicable 3D grape bunch model is needed. Thus, the contribution of this study is a novel technology for reconstructing a 3D model of a grape bunch with uniquely identified berries from 2D images captured in the real grape field environment.

Suitable crop loading: An effective method to improve "Shine Muscat" grape quality.

Berry thinning was applied to control crop load of "Shine Muscat" grape variety. Primary and secondary metabolites released during berries development were monitored, and the correlation between physicochemical parameters and core aroma compounds was analyzed. Results revealed a significant increase in single-berry weight and sugar-acid ratio of berries under low crop load conditions. Furthermore, phenolic content and antioxidant activity under low crop load were significantly higher than those of the other groups. Grapes with low crop loads also exhibited better aroma characteristics and higher sensory scores than those of the other groups, chiefly due to significantly increased terpene and C13-norisoprenoid contents and substantially decreased C6 compound and aldehyde contents. Moreover, correlation analysis revealed total soluble solid accumulation was positively correlated to terpene accumulation, while hexanal, 2-hexanal, (E)-2-hexanal, and (E)-2-octenal were positively correlated with titratable acidity content. Thus, better grape quality could be achieved by precisely controlling berry crop load.

End-to-end lightweight berry number prediction for supporting table grape cultivation

The advent of smart agriculture has revolutionized and streamlined various manual tasks in grape cultivation, one of which is berry thinning. This task necessitates experienced farmers to selectively remove a specific number of berries from the working bunch, as guided by the remaining number of berries in the bunch. In response, this paper introduces a novel real-time edge computing application that automates the process of counting the berries in a working bunch using a single 2D image. The proposed application employs YOLOv5-based object detection techniques (Jocher, 2021) to distinguish each working bunch and the visible and slightly occluded berries contained therein. The key contribution of this paper is to accurately predict the number of berries in the whole bunches including those not visible in a 2D image by harnessing the output from object detection to devise features based solely on bounding box information. In addition, the feature set is optimized by employing a wrapper feature selection method (Kohavi & John, 1997), in consideration of the limitations of edge computing devices. The eight selected features yield a mean absolute error (MAE) of 2.60 berries, tested on a dataset of 26,230 images. Only a slight increase over the initial 19-feature set, which achieved an MAE of 2.42 berries. Furthermore, the proposed approach has been successfully implemented and tested on an Android smartphone, the Sony Xperia 1 III, without the need for an internet connection. The overall computation time per image stands at an average of 0.333 s, confirming its potential for real-world application.

Supporting table grape berry thinning with deep neural network and augmented reality technologies

Berry thinning is a crucial process in table grape cultivation. Such visual features as bunch compactness, bunch form, and berry size are important factors affecting market value. Moreover, sufficient space for each berry to grow also largely influences the final product’s quality, such as the sugar concentration. Berry thinning requires professional skills, and it is usually accomplished only by experienced farmers. Furthermore, the appropriate period for berry thinning is limited to two weeks; hence, berry-thinning tasks have led to a bottleneck in terms of increasing the yield of table grape products. This paper addresses the aforementioned issue by proposing a system for empowering unskilled farmers to begin berry thinning without in-person coaching from expert farmers. The proposed system employs a deep neural network model to learn the knowledge required for identifying berries to be removed, and it uses augmented reality technology to display instructions based on this knowledge to naïve farmers through smart glasses. The proposed system was validated throughout the entire growing season in a real table grape field in Yamanashi Prefecture, Japan. It was confirmed that unskilled farmers can execute berry-thinning tasks immediately without training. Furthermore, they can become familiar with the proposed system quickly. The grape products from unskilled farmers who used the proposed system also had an 8.18 % higher average quality score than those from the skilled farmers.

Berry Thinning Affects the Fruit Quality Composition of Two Table Grape Cultivars under Linkage Greenhouse Conditions

Protected grape cultivation develops rapidly because of huge economic benefits. However, adverse environmental conditions (insufficient sunlight, high temperature, etc.) in protected cultivation led to low-quality berries. This study aimed to evaluate the effects of berry thinning on the quality attributes of two table grape cultivars (Baoguang and Cuiguang) under linkage greenhouse conditions. Three treatments (L, light berry thinning; M, moderate berry thinning; H, heavy berry thinning) were compared with the control (C, no berry thinning). Berry thinning increased berry weight, total soluble solids (TSS), fructose, glucose, the ratio of TSS to titratable acidity (TA), anthocyanin contents, berry firmness, and mineral contents (Ca, Fe, Na, Mg). Conversely, TA and organic acid profiles were decreased by berry thinning. Cultivars showed significant effects on most of the berry quality parameters. The interaction of cultivars by berry-thinning treatments affected sugar and acid components, anthocyanin contents, and mineral elements.

EFFECT OF EARLY BERRY THINNING AND GIRDLING ON GRAPE QUALITY OF CV. VICTORIA

The research was carried out at University of Belgrade Faculty of Agriculture experimental station “Radmilovac” on table grape Victoria cv with aim to improve grape quality and with consideration the introduction of these ampelographic measures in regular grapevine growing. The research included two treatments of berry thinning (thinning bunch tip - BtT and first lateral wink -BtW), girdling (G) and control (C). Combined effect of berry thinning and girdling were not examined. The following features were examined: fertility and yield, bunch and berry dimensions, bunch and berry structure, sugar content and total acidity. The thinning treatments did not have significant effect on uvometric parameters and grape quality, but they improved the yield by 41.7% (BtW) and 51.4% (BtT) in comparison to the control. It can be explained by bad fruit set influenced by unfavourable meteorological conditions during flowering in control treatment. Berry thinning achieves a better fruit set. Berry thinning should be applied as a regular ampelographic measure according to weather conditions during flowering phonological stage. Results confirm the positive influence of girdling. The yield was increased by 88,34% compared to control, berries had a higher diameter (for about 1mm with respect to control), fruit set and bunch mass were in higher level against other treatments, sugar content (17,00%), total acidity (5,75 g/L) were improved too. Girdling can be introduced as a regular ampelographic measure in the table cultivars vineyards, in order to obtain higher yields and better quality of table grape.

Instance Segmentation and Berry Counting of Table Grape before Thinning Based on AS-SwinT.

Berry thinning is one of the most important tasks in the management of high-quality table grapes. Farmers often thin the berries per cluster to a standard number by counting. With an aging population, it is hard to find adequate skilled farmers to work during thinning season. It is urgent to design an intelligent berry-thinning machine to avoid exhaustive repetitive labor. A machine vision system that can determine the number of berries removed and locate the berries removed is a challenge for the thinning machine. A method for instance segmentation of berries and berry counting in a single bunch is proposed based on AS-SwinT. In AS-SwinT, Swin Transformer is performed as the backbone to extract the rich characteristics of grape berries. An adaptive feature fusion is introduced to the neck network to sufficiently preserve the underlying features and enhance the detection of small berries. The size of berries in the dataset is statistically analyzed to optimize the anchor scale, and Soft-NMS is used to filter the candidate frames to reduce the missed detection of densely shaded berries. Finally, the proposed method could achieve 65.7 APbox, 95.0 , 57 , 62.8 APmask, 94.3 , 48 , which is markedly superior to Mask R-CNN, Mask Scoring R-CNN, and Cascade Mask R-CNN. Linear regressions between predicted numbers and actual numbers are also developed to verify the precision of the proposed model. RMSE and R2 values are 7.13 and 0.95, respectively, which are substantially higher than other models, showing the advantage of the AS-SwinT model in berry counting estimation.

Effect of berry thinning and Sitofex on fruiting of superior seedless grapevines

Effect of berry thinning and Sitofex on fruiting of superior seedless grapevines

Pengaruh Tingkat Penjarangan Beri terhadap Kualitas Buah Anggur Kediri Kuning dan Prabu Bestari

One of the problems encountered in cultivating grapes is the low quality of the fruit, the size of the fruit is still relatively small, the taste is not sweet, and the bunches are relatively compact. The problem of compactness or density of fruit bunches causes the shape, size, and maturity of the fruit in the bunch to be less uniform and there are some broken and decayed fruits. Thus, it is necessary to support cultivation technology to support the success of grape cultivation in order to increase the yield and quality of the fruit, one of which is through berry thinning activities. The purpose of this study was to determine the effect of berry thinning on the quality of the Kediri Kuning and Prabu Bestari grape varieties. The method used was a split plot design with the basic design of a randomized block design (RBD). The treatments tested were varieties and levels of fruit thinning. The first factor (main plot) was the variety consisting of Kediri Kuning (V1) and the Prabu Bestari variety (V2), while the second factor (sub-plot) was thinning level (P) with a level consisting of P0 = 0% control (without thinning). , P1 = fruit thinning 10%-25%, P2 = fruit thinning >25%-40%, P3 = fruit thinning 40%-55%. The results showed that thinning of berries in P3 treatment (>40-55%) gave a significantly higher effect on the variables of berry weight, berry diameter, fruit bunch length, fruit bunch weight, total dissolved solids, and vitamin C content.

Effect of berry thinning and Sitofex on fruiting of superior seedless grapevines

Effect of berry thinning and Sitofex on fruiting of superior seedless grapevines

Effects of Gibberelic Acid (GA3) and Berry Thinning on Güz Gülü, Özer Beyazı, Süleymanpaşa Beyazı and Tekirdağ Misketi Seedless Table Grape Cultivars

Effects of Gibberelic Acid (GA3) and Berry Thinning on Güz Gülü, Özer Beyazı, Süleymanpaşa Beyazı and Tekirdağ Misketi Seedless Table Grape Cultivars

Influence of Bunch Compactness and Berry Thinning Methods on Wine Grape Quality and Sensory Attributes of Wine in Vitis vinifera L. cv. ‘Monastrell’

Presently, there is no information available about the effect of bunch compactness and berry thinning methods on wine grape quality and sensory attributes of wine in the ‘Monastrell’ cultivar. Thus, the main aim of the present study was to determine the influence of bunch compactness and two berry thinning methods, which consisted of the reduction of 25% and 50% of the number of berries in each bunch, on wine grape quality and organoleptic quality of wine in this cultivar. Non-compact bunches and both berry thinning methods showed a significant reduction in total yield, bunch compactness, and bunch fresh mass compared with compact and control ones, respectively. However, these methods, especially the 50% one, significantly increased the content of total soluble solids and total phenolics. Furthermore, both berry thinning methods promoted the increase in total anthocyanins concentration in berries, as well as the hydrophilic total antioxidant activity. Berry thinning methods led to wines with greater sensory descriptors, such as fruity (odor and flavor), sour, sweet, aftertaste, and color, and were preferred by consumers. Finally, 50% berry thinning is the most useful tool to decrease bunch compactness and improve the overall quality of berries and sensory attributes of wines.

Effects of trellis system and berry thinning intensity on vine performance and quality composition of two table grape cultivars under protected cultivation in northern China

Strategies for improving table grape quality under protected conditions are worth discussing. Two grape cultivars Baoguang (BG) and Cuiguang (CG) were used to evaluate the effects of trellis systems (pergola trellis and closing Y shaped trellis which defined as SAYM) and berry thinning intensities (high thinning intensity, HT; medium thinning intensity, MT; light thinning intensity, LT) on vine performance and quality composition under protected cultivation. Vines trained on the pergola trellis system had a higher budbreak rate of 81.79%, but a lower proportion (70.16%) of bearing shoots. Vines trained on the SAYM trellis system had a larger leaf area index (LAI) of 145.38 m2 m−2, but lower transmission coefficient (TC, 0.27), photosynthetically active radiation (PAR,160.73 μmol m−2 s−1), mean leaf angle (MLA, 19.88°) and transpiration rate (Tr, 3.82 mmol m−2 s−1). Water content and pulling resistance (PR) were lower in berries on the SAYM trellis or within heavily thinned (HT) clusters. HT promoted the remarkable improvement in total soluble solids (TSS), ratio of TSS to titratable acidity (TA), pH, sugar constituents, external color density and skin total anthocyanins, and most of these indexes were also enhanced by SAYM trellis. TA maintained low (4.51 g kg−1) on the pergola trellis and decreased with thinning intensity enhanced. Despite that, the effects of trellis and thinning intensity on organic acid constituents varied in cultivars. Nutrition elements mostly tended to accumulate in HT berries. Trellis systems were active in altering the texture attributes of BG. In addition, medium thinning (MT) and light thinning (LT) exerted similar effects on most tested attributes.

Supporting Table Grape Berry Thinning with Deep Neural Network and Augmented Reality Technologies

Supporting Table Grape Berry Thinning with Deep Neural Network and Augmented Reality Technologies

Effect of pruning and mechanical fruit thinning on crop load and berry and wine composition of Tempranillo in Texas

Tempranillo is the second most planted variety in Texas. However, over-cropping can be an issue. Crop load can be managed by pruning and mechanical fruit thinning. Mechanizing fruit thinning provides three benefits: yield reduction, berry thinning to decrease cluster compactness and reduce fungal disease and lower production costs than fruit thinning by hand (Tardaguila et al., 2008). In this study, crop load was manipulated by pruning and mechanical fruit thinning and its effect was determined on berry and wine quality.

Effects of Berry Thinning on the Physicochemical, Aromatic, and Sensory Properties of Shine Muscat Grapes

The effects of the level of berry thinning (30% and 50% berry removal) on the quality and sensory properties of Shine Muscat grapes were investigated. As berry thinning increased, the total soluble solids content increased and titratable acidity decreased. Berry thinning increased berry size and cluster weight but caused no change in individual berry weight. Phenolic concentrations as measured by total phenolic, proanthocyanidin, and polymeric tannin concentrations tended to increase with an increase in berry thinning. Gas chromatographic analysis indicated that C6-compounds were the significant constituents of volatile alcohols and aldehydes; linalool was the most abundant monoterpene. Odor activity analysis indicated that (E)-2-hexen-1-ol, (E)-2-hexenal, 1-hexanal, (Z)-3-hexenal, (E)-β-damascenone, linalool, and (E)-linalool oxide were active odorants. Berry thinning increased the accumulation of linalool contributing to high sensory flavor scores in thinned berries. Furthermore, its oxidized derivative-linalool oxide-contributed to enhancing the Muscat flavor. In conclusion, berry thinning induced compositional changes in Shine Muscat grape berries by accelerating the ripening rate, contribution to improved sensory properties.

Advancement in Knowledge and Adoption of Grape Growing Farmers in Theni District of Tamilnadu

Grape (Vitis grape L.) could be a temperate fruit crop and conjointly cultivated beneath tropical and climatic zone regions within the world. This study on improved grape knowledge and adoption of recommended grape practices among farmers was conducted in the Theni district of Tamil Nadu by employing a combination of purposive and proportionate random sampling methods with 120 grape growers. The data were collected with the help of a well-structured and pretested interview schedule during July to August 2020-21. The district contributes significantly to the state's area of production in grapes. The area of cultivation of grapes to the state is substantial (79.80%). In the study it was concluded that cent percent of the grape growers had correct knowledge about soil type, planting, gap-filling, recut, supporting, weeding, irrigation type, training, pruning time, bud dormancy breaking chemical, micronutrient mixtures, fertigation, shoot thinning, subcane development, training the shoots, tipping, cluster and berry thinning, mealybug control, and downy mildew control. About 60.83 per cent of the grape growers belonged to medium level of knowledge about recommended practices of grape cultivation. The results showed overall adoption of the grape growers wasmedium level of adoption (71.67%). This study explores the keen view of the advancement in knowledge and adoption followed by grape cultivators in Theni District.

End-to-End Automatic Berry Counting for Table Grape Thinning

Bunch shape and berry size indicate the quality of table grapes and crucially affect their market value. Berry thinning is one of the most important tasks in grape cultivation to achieve an ideal bunch shape and to make sufficient space for individual berries. A successful practice by skilled grape farmers in Japan is using the number of berries in a bunch to guide the thinning process; hence, a technique for automatically counting the number of berries in a working bunch has been long desired by farmers to improve the efficiency of the thinning task. This research presents a novel end-to-end berry-counting technique based on a deep neural network (DNN), and its contributions are as follows. First, because a DNN requires massive training data, a novel data augmentation technique simulating the thinning process is proposed. Second, a new location-sensitive object detection model that integrates explicit location information and supplementary classification loss into a state-of-the-art instance segmentation model was proposed for detecting the number of berries in a working bunch with a high accuracy. Third, a set of features, together with their extraction algorithms, is designed for predicting the number of berries in a bunch (3D counting) using the berries detected on a single 2D image. Experiments using data collected from farmers’ grape-thinning process have been conducted to validate the accuracy and effectiveness of the proposed methods.

Yield reduction through cluster or selective berry thinning similarly modulates anthocyanins and proanthocyanidins composition in Refosco dal peduncolo rosso (Vitis vinifera L.) grapes

‘Refosco dal peduncolo rosso’ is a late-ripening and low-yielding red grape variety, mainly cultivated in Northeastern Italy (Veneto and Friuli Venezia Giulia), and characterized by relatively high anthocyanins and average-to-low tannins concentrations. Under Friuli’s climatic conditions, it is often challenging to maintain the Refosco dal peduncolo rosso grapes hanging on the vines long enough to match complete berry maturation before the rain season starts. Therefore, winegrowers normally perform cluster thinning in order to enhance or accelerate ripening. This study compared the effects of selective berry thinning (cluster shoulders and tips removal) and classical cluster thinning on fruit technological maturity, anthocyanin profile, and skin and seed proanthocyanidins concentration. Our results revealed that both thinning treatments induced a significant increase in total soluble solids, as well as total anthocyanins through the specific enhancement of OH- and di-substituted monoglucosylated anthocyanins. Additionally, skin high molecular weight proanthocyanidins was reduced by selective berry thinning, while mean degree of polymerization and percentage of galloylation were significantly decreased by both thinning treatments. These results showed that the yield reduction obtained by both methods were profitable to improve the maturation of Refosco dal peduncolo rosso grapes. However, the application of selective berry thinning provided a significant reduction of both skin high molecular weight proanthocyanidins and percentage of prodelphinidins. Therefore, the first evidences on grapes composition favored the cluster thinning technique as less time consuming, but more research on wine and sensory effects is needed to confirm the potential of selective berry thinning.