Grape Research Articles

Could 101-14 Mgt Rootstock Affect Post-Spring Frost Vine Developing? Preliminary Findings

(1) Background: Spring frost damage is a common phenomenon that occurs in Southern Chile that considerably affects vine productivity and grape quality. (2) Methods: A field trial was conducted in order to study vine phenology and berry physicochemical parameters in Chardonnay, Sauvignon Blanc and Pinot Noir ungrafted and grafted (onto 101-14 Mgt rootstock) grapevines after a spring frost. This event killed the totality of primary bud shoots when the vines reached the phenological stage of unfolded leaves. (3) Results: From budburst, to flowering of secondary bud shoots, ungrafted Sauvignon Blanc grapevines presented an advanced phenology, whereas 101-14 Mgt rootstock tended to advance the maturity of Pinot Noir grapevines from flowering to ripening of berries. At harvest, berries from secondary buds of vines grafted onto 101-14 Mgt rootstock showed higher soluble solids than the ones from ungrafted Chardonnay and Sauvignon Blanc vines. High total phenolic content was found in berries from secondary buds of the grafted vines, compared to the ones from the ungrafted vines. Berry soluble solids variability tended to statistically decrease toward harvest in the studied plant materials, and the maximum coefficient of variation for soluble solids, berry weight, berry firmness and berry size reached 9.5%, 25.9%, 18.6% and 8.9%, respectively. (4) Conclusions: These preliminary results may be interesting for the Southern Chilean viticulturists since it seems that 101-14 Mgt rootstock could affect phenology and grape berry maturity of grapevines established in the Cautín Valley after spring frost damage.

Pre-harvest foliar spraying of calcium and zinc preserves berries quality and mitigates chilling injury of grape during cold storage

The current study was conducted to elucidate the effect of single and combined post-veraison sprays of calcium nitrate (Ca, 2 %) and zinc sulfate (Zn, 1 %) on post-harvest quality attributes of ‘Sahebi’ grapes during cold storage. Grapes foliar-sprayed with combination of Ca and Zn showed higher flavonols (28 % myricetin, 4 % quercetin, and 15 % kaempferol), flavanols (6 % catechin, 29 % epicatechin, and 10 % epi‑gallocatechin) and anthocyanins (21 % malvidin, 16 % cyaniding and 13 % peonidin, 22 % petunidin) than controls. Moreover, Ca and Zn foliar application was also effective in preserving the levels of trans-resveratrol and phenolic acids in grape berries. The higher amount of phenolic compounds in Ca + Zn-treated grapes was accompanied with higher activity of antioxidant enzymes, lower activity of polyphenol oxidase, and lower incidence of fungal decay. In general, post veraison spray of Ca and Zn is promising viticultural operation for preserving berries bioactive compound and mitigating chilling injury of grape during cold storage.

Canopy-Applied Benzothiadiazole (BTH) during the Pre-Harvest Period as a Tool to Increase Polyphenol Accumulation and Color Intensity in Cabernet Gernischt and Cabernet Franc

Despite the wealth of studies on benzothiadiazole (BTH) and its capacity to modulate grape polyphenol metabolism, comprehensive data detailing polyphenol accumulation at various grape growth stages remain scarce. Therefore, the present study utilized pre-harvest (at 21 days after flowering) canopy-applied BTH (50 mg/L) on Cabernet Gernischt and Cabernet Franc grapes to investigate the physicochemical and polyphenolic changes during grape maturation. The results showed that BTH treatment significantly affected the accumulation of total phenols, flavonoids, flavanols, anthocyanins, and tannins. Concurrently, it induced an increase in colorimetric parameters (CIRG, L*, b*, a*, and C*ab), resulting in the treated grapes exhibiting a greater color intensity and enhanced red-bluish colorimetric characteristics. Moreover, the BTH treatment amplified the anthocyanin content in the grapes, with the levels of petunidin-3-O-glucoside and peonidin-3-O-glucoside exhibiting remarkable increases, particularly in the Cabernet Franc grape. Notably, the content of peonidin-3-O-glucoside even surpassed that of malvidin-3-O-glucoside throughout the growth stages, indicating significant advantages in the treated samples. Additionally, the levels of flavanol, flavonols, phenolic acids, and stilbenes experienced a significant boost post-treatment. In conclusion, the application of BTH treatment can effectively enhance the accumulation of polyphenols and intensify the color of Cabernet Gernischt and Cabernet Franc grapes, thereby significantly improving the overall quality of wine grapes and ensuring the production of higher-quality wines. The research findings will serve as a theoretical foundation and provide scientific data for the appropriate utilization of BTH in wine grape cultivation.

A precise grape yield prediction method based on a modified DCNN model

This paper presents an innovative method for predicting grape yield using a modified deep convolutional neural network (M−DCNN). This approach integrates advanced image processing techniques with deep learning algorithms to analyze high-resolution images of vineyards, enabling precise yield quantification. The M−DCNN model incorporates novel convolutional layers and activation functions to enhance accuracy and generalization capabilities. Extensive experiments were conducted using a varied dataset of grape varieties and vineyard conditions. The method involves image processing to identify grape clusters and monitor their growth at different stages. We evaluated the performance of several algorithms, including K-nearest neighbors (KNN), multinomial logistic regression (MLR), support vector machines (SVM), random forests (RF), deep convolutional neural network (DCNN), and M−DCNN, throughout the training and testing phases. The M−DCNN achieved the highest training accuracy at 97.35%, which represents a 0.85% improvement over the standard DCNN. Furthermore, in detecting grape berries, our method attained an average F1 score of 73.32% and coefficients of determination exceeding 0.98, showcasing high accuracy and precision. The results indicate that the M−DCNN model surpasses traditional yield estimation methods and existing machine learning models, affirming its potential to significantly enhance precision agriculture. This method offers a robust tool for accurate grape yield forecasting, facilitating informed decision-making in viticulture.

Ultra sensor based on color and UV-excited fluorescence images for predicting quality attributes of Shine-Muscat grape bunches at different maturity stages

Fruit maturity at harvest is a major factor in determining its quality. In this study, external skin color of grape has been utilized to predict their chemical content and, in turn, the maturity of the fruit. Measurements of the chemical content such as Brix and acidity were made on ten bunches of “Shine Muscat” grapes at three different harvest periods (immature, mature, and overmature). Using a machine vision system, color and UV-excited fluorescence images of grape berries and bunches were taken during the respective harvest stages. Acquired images were processed using ImageJ to obtain RGB values. Rratio and a*/b* are strongly related to Brix and sugar-to-acid ratio of grape fruit, with regression coefficients of 0.5626 and 0.5180, repectively. It was found that a* color index was the best predictor of grape bunch maturity. Furthermore, discriminant analysis has shown that color images of grape berries perform better than 365 nm fluorescence images.

Supplementing with monochromatic blue LED light during the day, rather than at night, increases anthocyanins in the berry skin of grapevine (Vitis vinifera L.).

Supplying monochromatic blue LED light during the day, but not at night, promotes early coloration and improves anthocyanin accumulation in the skin of grape berries. Specific light spectra, such as blue light, are known to promote the biosynthesis and accumulation of anthocyanins in fruit skins. However, research is scarce on whether supplement of blue light during different periods of one day can differ in their effect. Here, we compared the consequences of supplying blue light during the day and night on the accumulation of anthocyanins in pigmented grapevine (Vitis vinifera) berries. Two treatments of supplemented monochromatic blue light were tested, with light emitting diodes (LED) disposed close to the fruit zone, irradiating between 8:00 and 18:00 (Dayblue) or between 20:00 and 6:00 (Nightblue). Under the Dayblue treatment, berry coloration was accelerated and total anthocyanins in berry skins increased faster than the control (CK) and also when compared to the Nightblue condition. In fact, total anthocyanin content was similar between CK and Nightblue. qRT-PCR analysis indicated that Dayblue slightly improved the relative expression of the anthocyanin-structural gene UFGT and its regulator MYBA1. Instead, the expression of the light-reception and -signaling related genes CRY, HY5, HYH, and COP1 rapidly increased under Dayblue. This study provides insights into the effect of supplementing monochromatic LED blue light during the different periods of one day, on anthocyanins accumulation in the berry skin.

Grape Maturity Estimation Using Time-of-Flight and LiDAR Depth Cameras.

This article investigates the potential for using low-cost depth cameras to estimate the maturity of green table grapes after they have been harvested. Time-of-flight (Kinect Azure) and LiDAR (Intel L515) depth cameras were used to capture depth scans of green table grape berries over time. The depth scans of the grapes are distorted due to the diffused scattering of the light emitted from the cameras within the berries. This causes a distance bias where a grape berry appears to be further from the camera than it is. As the grape aged, the shape of the peak corresponding to the grape became increasingly flattened in shape, resulting in an increased distance bias over time. The distance bias variation with time was able to be fitted with an R2 value of 0.969 for the Kinect Azure and an average of 0.904 for the Intel L515. This work shows that there is potential to use time-of-flight and LIDAR cameras for estimating grape maturity postharvest in a non-contact and nondestructive manner.

The Metabolomic Profiling of the Flavonoid Compounds in Red Wine Grapes and the Impact of Training Systems in the Southern Subtropical Region of China.

Flavonoids play an important role in forming wine grapes and wine quality characteristics. The flavonoids of three winter red wine grapes, Yeniang No. 2 (YN2), Marselan (Mar), and Guipu No. 6 (GP6), were analyzed by ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QQQ-MS). Furthermore, the flavonoids in GP6 grapevines using two types of training systems, namely, trellis (T) and espaliers (E), were also compared in this study. Overall, 196 flavonoid metabolites, including 96 flavones, 38 flavonols, 19 flavanones, 18 polyphenols, 15 anthocyanins, 7 isoflavones, and 3 proanthocyanidins, were identified. The flavonoid profiles were remarkably different among these three grape varieties, while they did not change much in the GP6 managed on trellis and espaliers. Grape varieties with different genetic backgrounds have their own unique flavonoid profiles. Compared with Mar-T, isoflavones and flavonols presented higher contents in GP6-T and YN2-T, which mainly contain glycitein, genistin, calycosin, kaempferide, isotrifoliin, and ayanin. The anthocyanin content was significantly higher in YN2-T than in the other two varieties. YN2 and GP6-T present a more stable color, with significantly more acetylated diglucosides and methylated anthocyanins in YN2-T and GP6-T than in Mar-T. Notably, GP6 had more varied flavonoids and the better characteristics to its flavonoid profile out of these three varieties, due to it containing a higher number of anthocyanins, flavone, and flavonols and the greatest number of different flavonoid metabolites (DFMs), with higher contents than YN2 and Mar. Compared with the trellis training system, the espaliers training system increased the content of flavonoids detected in GP6 grape berries; however, the composition of flavonoids strictly depends on the grape variety.

MECHANICAL PROPERTIES OF SEVERAL LOCAL AND INTRODUCED GRAPE VARIETIES: RESEARCH AND EVALUATION OF THEIR TECHNOLOGICAL SUITABILITY

The article presents the findings from a study evaluating the morphological, biological and technological characteristics of various table and technical grape varieties cultivated in the Republic of Azerbaijan. The research adhered to the descriptors of the International Organization of Vine and Wine (OIV). The study reveals a wide range in the size of grape bunches, with medium, large and small bunches being predominant. Notably, the local and introduced varieties Arna-grna, Khindogny, Hamashara, Shirvanshahy and Moldova exhibited superior morphological traits such as mass, volume and size of bunches. Juice yield, a key indicator of technological suitability, ranged from 45.5% to 80.0%. The Shiraz variety had the lowest juice yield (45.8%), whereas the Moldova (76.8%) and Uni Blanc (80.0%) varieties had the highest. Most varieties had small berries, but Arna-grna (481 g), Gyanjavi (341 g) and Moldova (317 g) were considered medium. The sugar content in the berries was categorized as average, high or very high, with Shirvanshahy having the highest sugar content (25.0 g/100 cm3). The titratable acidity of the varieties was low to average, while the active acidity was mainly low.

Botrytis cinerea causes different plant responses in grape (Vitis vinifera) berries during noble and grey rot: diverse metabolism versus simple defence.

The complexity of the interaction between the necrotrophic pathogen Botrytis cinerea and grape berries (Vitis vinifera spp.) can result in the formation of either the preferred noble rot (NR) or the loss-making grey rot (GR), depending on the prevailing climatic conditions. In this study, we focus on the functional gene set of V. vinifera by performing multidimensional scaling followed by differential expression and enrichment analyses. The aim of this study is to identify the differences in gene expression between grape berries in the phases of grey rot, noble rot, and developing rot (DR, in its early stages) phases. The grapevine transcriptome at the NR phase was found to exhibit significant differences from that at the DR and GR stages, which displayed strong similarities. Similarly, several plant defence-related pathways, including plant-pathogen interactions as hypersensitive plant responses were found to be enriched. The results of the analyses identified a potential plant stress response pathway (SGT1 activated hypersensitive response) that was found to be upregulated in the GR berry but downregulated in the NR berry. The study revealed a decrease in defence-related in V. vinifera genes during the NR stages, with a high degree of variability in functions, particularly in enriched pathways. This indicates that the plant is not actively defending itself against Botrytis cinerea, which is otherwise present on its surface with high biomass. This discrepancy underscores the notion that during the NR phase, the grapevine and the pathogenic fungi interact in a state of equilibrium. Conversely the initial stages of botrytis infection manifest as a virulent fungus-plant interaction, irrespective of whether the outcome is grey or noble rot.

A lightweight and efficient model for grape bunch detection and biophysical anomaly assessment in complex environments based on YOLOv8s.

As one of the most important economic crops, grapes have attracted considerable attention due to their high yield, rich nutritional value, and various health benefits. Identifying grape bunches is crucial for maintaining the quality and quantity of grapes, as well as managing pests and diseases. In recent years, the combination of automated equipment with object detection technology has been instrumental in achieving this. However, existing lightweight object detection algorithms often sacrifice detection precision for processing speed, which may pose obstacles in practical applications. Therefore, this thesis proposes a lightweight detection method named YOLOv8s-grape, which incorporates several effective improvement points, including modified efficient channel attention (MECA), slim-neck, new spatial pyramid pooling fast (NSPPF), dynamic upsampler (DySample), and intersection over union with minimum point distance (MPDIoU). In the proposed method, MECA and NSPPF enhance the feature extraction capability of the backbone, enabling it to better capture crucial information. Slim-neck reduces redundant features, lowers computational complexity, and effectively reuses shallow features to obtain more detailed information, further improving detection precision. DySample achieves excellent performance while maintaining lower computational costs, thus demonstrating high practicality and rapid detection capability. MPDIoU enhances detection precision through faster convergence and more precise regression results. Experimental results show that compared to other methods, this approach performs better in the grapevine bunch detection dataset and grapevine bunch condition detection dataset, with mean average precision (mAP50-95) increasing by 2.4% and 2.6% compared to YOLOv8s, respectively. Meanwhile, the computational complexity and parameters of the method are also reduced, with a decrease of 2.3 Giga floating-point operations per second and 1.5 million parameters. Therefore, it can be concluded that the proposed method, which integrates these improvements, achieves lightweight and high-precision detection, demonstrating its effectiveness in identifying grape bunches and assessing biophysical anomalies.

Impact of the Plant Growth-promoting Rhizobacterium Streptomyces saraceticus Strain 31 on Berry Quality of ‘Benifuji’ Grape: Improvements through the Reconfiguration of Fine Root Morphology and Vessel Anatomy

In an effort to mitigate the environmental impact of chemical fertilizers, plant growth-promoting rhizobacteria (PGPR) have emerged as a more sustainable alternative. Streptomyces saraceticus 31 (‘SS31’), a new strain of biocontrol bacteria, was inoculated into rhizosphere soils of ‘Benifuji’ grape to evaluate its impact on grape roots and berries. The results indicated significant improvements in soil fertility, with higher levels of organic matter, phosphorus, potassium, and nitrate nitrogen compared with those of the controls. Moreover, ‘SS31’ application elicited a notable reduction in soil pH levels, along with a substantial augmentation in the enzymatic activities of both phosphatase and invertase. The grapes treated with ‘SS31’ exhibited a notable increase in the number, length, surface area, and volume of fine roots in both 0- to 10-cm and 10- to 20-cm soil profiles. The application of ‘SS31’ resulted in the observation of greater diameter, lower density, and larger lumen area, along with increased specific hydraulic conductivity in the vessels of roots with 1- to 2-mm diameters. Despite a slight reduction in berry weight compared with that of the controls, ‘Benifuji’ grape berries displayed higher total soluble solids and lower total titratable acidity after ‘SS31’ application. Furthermore, ‘SS31’ treatment elevated the levels of volatile compounds in berries, especially fatty acid-derived compounds. A network analysis revealed a robust positive correlation between the observed improvements in grape berry quality and the morphology as well as the hydraulic conductivity of the grape fine roots. In conclusion, these findings suggest that ‘SS31’ has the potential to enhance grape root function by expanding the root absorption area and facilitating water transportation. This, in turn, may improve the flavor and aroma of ‘Benifuji’ grape berries.

How to better estimate bunch number at field level?

In viticulture, early-season estimation of average number of grape bunches per vine is crucial for vineyard planning, investments and marketing (Laurent et al., 2021). Although sampling is widely carried out to estimate grape bunches per vine, there is no clearly established sampling protocol that can be used as a reference when performing these estimations. Each practitioner therefore has their own sampling protocol. In this work, the effect of differences between sampling protocols in terms of estimation errors were investigated to give some recommendations on the best possible sampling practices.

Decision Support System for the Assessment and Enhancement of Agrobiodiversity Performance

The industrialisation of agriculture and changes in production systems have contributed to a biodiversity decline worldwide. Developing accurate and adequate assessment methods can encourage farmers to support more sustainable agricultural management. This study presents a decision support system to promote agrobiodiversity that incorporates not only a quantitative assessment of relevant indicators of agrobiodiversity performance but also provides enhancement practice recommendations and associated benefits, presenting an action plan in order of priority. Additionally, the decision support system allows a visual comparison between biodiversity composite indicators and indicators representing pest control and crop yield. Since grape cultivation is considered one of the most intensive agricultural systems, thus significantly impacting biodiversity, the elaborated decision support system was tested on a viticultural agroecosystem in the demarcated Douro region in Portugal. The results demonstrated the decision support system functioning according to the selected methodology and allowed the identification of future lines for investigation. During the analysed period, the following were verified: an increase of 2% in the biodiversity indicator, 130% in harvest yield, and 2077% in the enemy-to-pest ratio. It is expected that the elaborated DSS will offer a significant contribution by bridging communication gaps on alternative management options to improve biodiversity performance in agricultural systems.

Методические подходы (гипотезы) к оценке пригодности сортов винограда к возделыванию в корнесобственной культуре

Abstract. One of the ways to reduce the cost of grapes and intensify the industry is to preserve and expand the own-root culture of phylloxera-tolerant grape varieties. Currently, there are all the prerequisites for expanding the own-root grape culture – a number of varieties have been obtained that are resistant to phylloxera and root rot with good quality of grape berries and their processed products. To extend the life of plantings and increase their profitability, it is important to identify grape varieties for cultivation in ownroot culture. However, comparative pairwise studies of varieties in own-rooted and grafted culture are lengthy and costly. The purpose of the research is to search for criteria for the accelerated assessment of Vitis vinifera L. varieties for suitability for cultivation in own-root culture using the example of genotypes of the DBESV&VG breeding. The research was carried out at the experimental base and the Ampelographic Collection of DBESV&VG in 2017-2023. The object of research is model and fruit-bearing rooted and grafted plants of different grape varieties with different resistance to phylloxera, 47 seed varieties of the Ampelographic Collection of DBESV&VG, 16 varieties and hybrid forms of DBESV&VG breeding. It has been assumed and experimentally confirmed that the higher the seed productivity of a grape variety (high proportion (mass) of seeds in a bunch, low seed index of the berry), the higher the tolerance of the variety to root phylloxera. Grape varieties, the reaction of which is expressed in an increase in seed progeny (“mass of seeds in a bunch”) with hormonal regulation of the development of rooted plants, can be cultivated in a rooted culture against the background of phylloxera. Keywords: grapes, phylloxera, root culture, phylloxera tolerance, seed productivity, phylloxera resistance criteria, hormone regulation

Essential oil from orange peel in the control of Botrytis cinerea and in the postharvest conservation of ‘Benitaka’ table grape

The objective of this work was to evaluate the efficiency of essential oil from orange peel in the refrigerated conservation of the ‘Benitaka’ table grape, as well as to evaluate its in vitro effectiveness on Botrytis cinerea, the causal agent of gray mold. Grapes were harvested from a commercial field in the municipality of Cambira, Paraná, during the 2022 and 2023 seasons. The experimental design was completely randomized, with four treatments and five replications of five bunches per plot. The treatments were: a) control; b) essential oil from orange peel at 4.0 mL of the commercial product (c.p.) L-1; c) dual phase SO2-generating pads containing 1 and 4 g of the active ingredient (a.i.) in the fast and slow phases, respectively; and d) essential oil from orange peel at 4.0 mL c.p. L-1 associated with the dual phase SO2-generating pads containing 1 and 4 g of the a.i. in the fast and slow phases, respectively. A commercial product containing 61.14 g L-1 (6% w/v) of 4-isopropenyl-1-methylcyclohexane, the source of orange essential oil, was applied by spraying it directly onto the bunches. After drying, the grape bunches were stored in a refrigerated chamber at 1.0±1°C and 95% relative humidity. The following variables were assessed 30 and 45 days after the beginning of cold storage: the incidence of gray mold on berries, loss of bunch mass, stem browning, shattered berries, and bleaching. The minimum inhibitory concentration for the development of B. cinerea was determined, and fungal mycelia were observed using scanning electron microscopy to evaluate the in vitro efficacy of orange essential oil. The data were subjected to analysis of variance, and the means were compared using Fisher's difference test at 5% probability. The effectiveness of orange essential oil in suppressing the development of B. cinerea was demonstrated both in vivo and in vitro, making it a safe alternative for the postharvest conservation of 'Benitaka' table grapes.

ИСТОЧНИКИ КРУПНОЯГОДНОСТИ СОРТОВ ВИНОГРАДА АНАПСКОЙ АМПЕЛОГРАФИЧЕСКОЙ КОЛЛЕКЦИИ

The aim of the study is to examine grape varieties in the collection of the Anapa Experimental Station in order to identify genetic sources of large-berry fruit. Varieties that are donors or sources of economically valuable traits, such as high productivity, large-berry fruit, stress resistance, adaptability, and taste, are found among representatives of the eco-geographical groups of European-Asian grapes. This work is relevant because it is the foundation for the selection process of grape culture and the production of new zoned large-berry varieties that are in great demand on the market and necessary in times of import substitution. Currently, the collection consists of many varieties of different eco-geographical origins, table and technical uses. The gene pool of grapes is replenished every year. These varieties are used annually in breeding to develop new high-quality grape varieties. The objects of research were the source varieties of large-berry grapes from different geographical zones. In this research work, modern programs and me-thods were used along with traditional breeding methods. The paper presents four sources of large-berry grapes, gives their brief characteristics, shows the dynamics of the main phenological and agrobiological indicators for 2021–2023. Among the source varieties, the following varieties stand out in terms of the frui-ting coefficient: Brigantina (K1 – 1.0–1.2) and Muromets (K1 – 1.0–1.1), and in terms of yield per bush – Pobeditel, Brigantina and Yubiley Moldavii. These varieties are used in experimental work on varietal directed crossing of supposed carriers of economically valuable selection traits and further obtaining seeds of new hybrid offspring.

An Economic Analysis of Credit Utilization Pattern and Credit Gap for Grape Cultivation and Value Addition (Raisin Making) in Vijayapura District of Karnataka, India

Credit is an important factor triggering agricultural growth when it is utilized properly. The present study aims to analyze the credit utilization pattern and credit gap for grape cultivation and value addition (raisin making) in Vijayapura district, which is having the highest area under grape cultivation in Karnataka state. As the grape requires high maintenance expenses, its economic analysis is of great importance in its present status. The primary data was collected from 90 respondent grape farmers in the study area. The finding of the study revealed that the sample farmers borrowed an average of ₹ 1,46,883 from all the institutional sources for grape cultivation, and the utilization of borrowed institutional credit for grape production was ₹ 1,09,376 (74.5%), and ₹ 37,507 (25.5%) of borrowed institutional credit was diverted for raisin production. For raisin making the sample farmers borrowed a total of ₹ 1,67,372 in credit from non-institutional sources in the study area. ₹ 138,440 (82.72%) of borrowed non-institutional credit was utilized for raisin making and ₹ 28,932 (17.28%) of borrowed credit was diverted other purposes by the sample farmers. The total credit gap was found to be 58.49, 59.97, and 59.12 per cent from commercial banks, regional rural banks, and cooperative bank/societies respectively. The findings also indicated that the sample farmers used the borrowed institutional and non-institutional credit more effectively to increase their revenue, diverting it less often for other uses. Many farmers do not receive institutional credit in an adequate quantity, at the appropriate time, or at a reasonable cost. Therefore, there is a need to focus on existing access and the quantum of formal credit used for agricultural purposes by different farmers in rural areas of Vijayapura district.

Maintenance of post-harvest antioxidant quality in ‘Niagara Rosada’ grape using salicylic acid

Salicylic acid is a plant growth regulator used in grapes to maintain postharvest quality. ‘Niagara Rosada’, a table grape, although much appreciated for its flavor, has a short shelf life. We evaluated the influence of postharvest application of different doses of salicylic acid on the quality of ‘Niagara Rosada’ after harvest in an effort to control rates of berry drop and decay, as well as to maintain the quality of grape bunches during refrigerated storage. Freshly harvested bunches of ‘Niagara Rosada’ (Vitis labrusca x V. vinifera) were immersed in salicylic acid solutions at concentrations of 0.0, 0.28, 0.55, 0.83, and 1.10 g L-1, and then refrigerated (5 ± 1 °C and 95 ± 5 % RH) for 20 days. Physical and chemical analyses of grapes were performed at 5-day intervals. Salicylic acid maintained the postharvest quality of ‘Niagara Rosada’ grapes throughout storage. The lowest concentration of salicylic acid (0.28 g L-1) effectively induced the synthesis of phenolic compounds and improved the antioxidant capacities of both grapes and stems. High levels of salicylic acid (0.83 and 1.10 g L-1) resulted in an increase in anthocyanin content in fruit and enzyme activities (peroxidase and superoxide dismutase) in stems, enhancing conservation and reducing levels of decay and berry drop.

Hydrogen Cyanamide: A Chemical to Prepone Natural Budburst Timing of Grapevine Cultivars in Nepalese Context

Grapes primarily belongs to mediterranean climate but overtime due to successful vine management practices, its cultivation has been extended to sub-tropics and tropics. In Nepal, grape cultivation has been started about 8 decades ago, and the demand of this crop has been increasing every year. However, the critical challenge of heavy rainfall coinciding with the berry harvest period has limited the production window, necessitating innovative solutions. This study explores the potential of grape cultivation in Nepal by assessing significance of hydrogen cyanamide (HC) application to ensure early and uniform budburst and therefore fruit maturity before monsoon. Winter pruning and HC application at 2-5% concentration has been found effective in preponing budburst and maturity in some grapes varieties ‘Steuben’ and ‘Cabernet Sauvignon’ in Nepal, but the results depend on date and dose of HC application in particular variety and specific growing condition. Application of HC at 2% concentration has resulted in earlier budburst by about 3 weeks in var. Cabernet Sauvignon in Dhading, Nepal. Also, the earlier treatment of HC and pruning in comparison to normal time of pruning (December 15 to January 15) has resulted in earlier and higher budburst and observed fruitfulness in varieties like ‘Steuben’ and ‘Cabernet Sauvignon’ in warm temperate belt of Nepal. Thus, the study concludes the prepone of natural budburst is a must need practice for successful viticulture in terai and mid-hills of Nepal. It also emphasizes the need of more research to optimize the application of HC and ensure its efficacy in advancing budburst and maturity specific to variety and locality. Overall, the findings aim to inspire growers, enhance commercial viability, and contribute valuable insights to the viticulture sector in Nepal.