Grapevine Yield Research Articles

Dynamics of Energy Fluxes in a Mediterranean Vineyard: Influence of Soil Moisture

Accurate evaluation of grapevine water use is essential for optimizing water management and maximizing grapevine yield and berry quality in Mediterranean climates. Understanding the water and heat flux dynamics in a vineyard during grapevine berry maturation is of utmost importance. This study focuses on evaluating sensible and latent energy fluxes at the canopy, the soil beneath the canopy, and the interrow areas. The primary objective is to develop a model framework for accurately estimating these energy fluxes, contributing to a better understanding of their behavior during berry ripening. The model’s accuracy was assessed by comparing the estimated fluxes with those measured by an eddy-covariance system installed at a reference height of three meters in the experimental vineyard. This validation step was essential to confirm the model’s ability to capture the intricate energy flux dynamics of the vineyard, especially during grape maturation. The results revealed a high level of agreement between the observed and estimated fluxes, confirming the model’s reliability. This comprehensive evaluation of energy fluxes provides valuable insights for optimizing irrigation strategies. By doing so, this study contributes to improving grape quality, ensuring sustainable water resource use, and ultimately enhancing vineyard productivity in arid and water-scarce regions.

NEMATOFAUNA PRESENT IN THE VENETIAN VINEYARD

Attacks of plant-parasitic nematodes can seriously affect grapevine yield and quality, also due to synergistic damages caused by the co-presence of nematodes and viruses. A survey was carried out in vineyards from a D.O.C.G. area of Veneto region, Italy, in order to better understand the relationship between grapevine plants and presence of phytonematodes. Most concerns were raised by detection of species as Mesocriconema xenoplax and Xiphinema index, this latter as the vector of grapevine fanleaf virus (GFLV), the most economically important nepovirus in vineyards. Some individuals of Pratylenchus vulnus were also found. Numerous predaceous nematodes as Mononchida were found within several soil samples. Mononchida play an important role in contrasting the spread of other nematodes, including plant-parasitic nematodes. During the survey, other non-plant-parasitic nematodes as Dorylaimina and Rhabditida were homogeneusly distribuited among samples. Key Words: grapevine, Grapevine fanleaf virus (GFLV), nematodes, trophic groups, Xiphinema index.

The influence of different methods of under-vine management on the structure of vegetation and the qualitative parameters of the grapes in the Moravian wine region

ABSTRACT The present article explores the importance of vineyard soil management. Studies on under-vine management have yielded a wide range of results, with some indicating potential benefits for vine growth and productivity. However, the methods of under-vine management and their specific effects on vineyard parameters require further research. The aim of this study is to evaluate the relationships existing between the different types of management of under-vine areas and the vegetation grown in this zone and to determine the effects of under-vine management on the yield and quality of Traminer grapevines. By examining various approaches, the research aims to provide insights into the optimising of vineyard management methods to achieve enhanced biodiversity and grape quality in this specific geographical context. The findings indicated that management of the under-vine area can impact the composition of plants, grape yield and quality. Under-row management had an effect on the number of plant species and their composition. The highest weight of bunches was found in MIX (a species from the Fabaceae family), while the lowest was found in the MECH treatment (bare soil). MULCH, MONO and MIX consistently had higher yeast assimilable nitrogen (YAN) in grapes than other treatments. In many of the evaluated parameters, the influence of the seasons was evident.

Green-Nano Manganese and Its Impact on the Growth, Yield, and Fruit Properties of Flame Seedless Grapes

The present work aimed to evaluate green-nano manganese produced at the Microbial Biotechnology Department, National Research Centre, Egypt, and assess its impact on the growth, yield, and fruit properties of grapevines. To this end, two experiments were conducted. The first was microbiological, where several incorporation strategies were utilized to enrich the yeast with manganese, as follows: (1) manganese was added to the liquid medium (non-growth phase), and (2) manganese was added after 24 h of incubation (growth phase). The results showed that the non-growth phase had a reduced possibility of medium contamination. The manganese concentration in the yeast cells was increased due to manganese sulfate in the medium. The manganese incorporation in yeast cells was 99.93% (1.205 × 105) higher than that of the medium at 0.0195 g/L of manganese. Although the concentration of manganese in the medium raised the optical density (OD) of the yeast cell biomass, manganese sulfate had no passive influence on it. The second experiment was horticultural, where Flame Seedless grapevines were sprayed with frozen and active fresh yeast enriched with manganese that resulted from the microbiological experiment. Grapevines were sprayed twice a year at 10 or 20 cm3/L, and the results were compared with those for the mineral and chelate forms. The results demonstrated that yeast extracts in both forms showed positive effects on grapevine. The most effective treatment with regard to growth, yield, and fruit properties was frozen yeast enriched with manganese at 20 cm3/L, which yielded 10.14 and 12.6 kg/vine, compared with the control, which recorded 3.7 and 5.6 kg/vine in the two seasons, respectively.

Assessing the influence of partial canopy cover and temperature variability on late-season dehydration in grape berries

Late-season dehydration (LSDN) is a physiological disorder affecting grape berry water content, resulting in dehydration. Vineyards in the Aegean Region of western Türkiye have experienced problems with LSDN, particularly during periods of high temperatures. This research examines how partial canopy covering materials affect temperature differentials inside and outside the canopy, including the determination of LSDN grape berries of Sultan 7 (Vitis vinifera L.). A partial shading net (PS) was employed to prevent LSDN in the grape berries, and shading net and polyethylene material (PSP) were deployed to assess the impact of increasing canopy temperatures on the occurrence of LSDN in grape berries. Although partial covering materials did not substantially affect grapevine yield, the control group produced the largest and the heaviest berries. In the second year, warmer conditions led to more clusters with LSDN-affected berries and increased sunburn damage on clusters. PS showed a high healthy cluster rate of 72.50%, while PSP and control showed lower rates of 63.60% and 58.10%, respectively. Throughout the study period, PS exhibited 9.02% LSDN berries, while the control and PSP showed 17.10% and 16.70% clusters with LSDN berries in the total harvested clusters, respectively. The study showed that PS treatment alleviated LSDN symptoms in clusters.

Improving Water Use Efficiency, Yield, and Fruit Quality of Crimson Seedless Grapevines under Drought Stress

Drought stress is a group of abiotic stresses that affects plant growth and yield production. A field experiment over two successive seasons (2021–2022 and 2022–2023) in sand soil was conducted to investigate the integration effect of deficit irrigation, soil amendment “hundzsoil”, and the spraying of proline on the water use efficiency (WUE), yield, and fruit quality of 8-year-old Crimson seedless table grapes. Four application rates of soil amendment (0, 2, 4, and 6 kg hundzsoil /vine) were added during the dormancy period, and four irrigation levels at 125, 100, 75, and 60% of the field capacity were applied just before flowering until harvest. Proline at two levels (0 and 500 ppm) was applied as a foliar spray. Parameters such as bud fertility, weight of 100 berries, juice volume, and cluster number were positively affected by irrigation at 75% FC along with applying hundzsoil at 2 and 4 kg/vine under proline spray in both seasons. Irrigation at the 125% FC level with a 6 kg hundzsoil application under proline spray resulted in the highest yield, berries number, cluster length, cluster weight, and total anthocyanin in both seasons. The TSS/acidity ratio was significantly and positively affected by deficit irrigation (60% FC level) under hundzsoil at a rate of 4 kg alongside proline spray. Reducing irrigation to 60% FC without hundzsoil and proline spray negatively affected numerous growth parameters and the yield. However, irrigation at 60% FC alongside 6 kg of hundzsoil and proline showed the highest IWUE in both seasons. Proline spray was a key factor in conserving water used for irrigation. This study recommends using deficit irrigation alongside hundzsoil application under proline spray as an adequate strategy for water use efficiency and improving the yield and fruit quality of Crimson seedless grapevines cultivated in sand soil.

Determining the Climatic Drivers for Wine Production in the Côa Region (Portugal) Using a Machine Learning Approach

The Côa region in inner-northern Portugal heavily relies on viticulture, which is a cornerstone of its economy and cultural identity. Understanding the intricate relationship between climatic variables and wine production (WP) is crucial for adapting management practices to changing climatic conditions. This study employs machine learning (ML), specifically random forest (RF) regression, to predict grapevine yields in the Côa region using high-resolution climate data for 2004–2020. SHAP (SHapley Additive exPlanations) values are used to potentially explain the non-linear relationships between climatic factors and WP. The results reveal a complex interplay between predictors and WP, with precipitation emerging as a key determinant. Higher precipitation levels in April positively impact WP by replenishing soil moisture ahead of flowering, while elevated precipitation and humidity levels in August have a negative effect, possibly due to late-season heavy rainfall damaging grapes or creating more favorable conditions for fungal pathogens. Moreover, warmer temperatures during the growing season and adequate solar radiation in winter months favor higher WP. However, excessive radiation during advanced growth stages can lead to negative effects, such as sunburn. This study underscores the importance of tailoring viticultural strategies to local climatic conditions and employing advanced analytical techniques such as SHAP values to interpret ML model predictions effectively. Furthermore, the research highlights the potential of ML models in climate change risk reduction associated with viticulture, specifically WP. By leveraging insights from ML and interpretability techniques, policymakers and stakeholders can develop adaptive strategies to safeguard viticultural livelihoods and stable WP in a changing climate, particularly in regions with a rich agrarian heritage, such as the Côa region.

Exploring Seaweed and Glycine Betaine Biostimulants for Enhanced Phenolic Content, Antioxidant Properties, and Gene Expression of Vitis vinifera cv. "Touriga Franca" Berries.

Climate change will pose a challenge for the winemaking sector worldwide, bringing progressively drier and warmer conditions and increasing the frequency and intensity of weather extremes. The short-term adaptation strategy of applying biostimulants through foliar application serves as a crucial measure in mitigating the detrimental effects of environmental stresses on grapevine yield and berry quality. The aim of this study was to evaluate the effect of foliar application of a seaweed-based biostimulant (A. nodosum-ANE) and glycine betaine (GB) on berry quality, phenolic compounds, and antioxidant activity and to elucidate their action on the secondary metabolism. A trial was installed in a commercial vineyard (cv. "Touriga Franca") in the Cima Corgo (Upper Corgo) sub-region of the Douro Demarcated Region, Portugal. A total of four foliar sprayings were performed during the growing season: at flowering, pea size, bunch closer, and veraison. There was a positive effect of GB in the berry quality traits. Both ANE and GB increased the synthesis of anthocyanins and other phenolics in berries and influenced the expression of genes related to the synthesis and transport of anthocyanins (CHS, F3H, UFGT, and GST). So, they have the potential to act as elicitors of the secondary metabolism, leading to improved grape quality, and also to set the foundation for sustainable agricultural practices in the long run.

Effect of Foliar Application of Potassium Fertilizer on Yield, Fruit Quality, and Cold Hardiness of Vitis spp. ‘Chambourcin’

ABSTRACT Temperate regions experiencing sub-zero temperatures negatively impact grapevine yield. Potassium has been claimed as a cryoprotectant to improve cold hardiness in grapevine. This study investigated the effect of foliar application of liquid potassium-based fertilizer, ReaXTM, on cold-hardiness of grapevine Vitis spp. “Chambourcin” along with its effect on yield and fruit quality. The vines were sprayed four to five times between the fruit set and veraison stage at a concentration of 1.5% (v/v) for two consecutive seasons. Petioles were analyzed for nutrients, clusters for yield and fruit quality, and cold hardiness was determined by differential thermal analysis and bud injury assessment. Potassium deficiency was observed in all treatments, and its content did not increase significantly in treated vines. Berry potassium levels and total soluble solids were generally higher in K-treated vines, however, there was no significant effect on yield and other fruit quality traits. Significant differences in cold hardiness levels were observed in both dormant seasons. Foliar application of potassium is a promising cultural practice to increase cold hardiness, but further studies are needed to understand the limits of its effectiveness.

Adapting service crop termination strategy in viticulture to increase soil ecosystem functions and limit competition with grapevine

Soil management and particularly service crops are a promising solution for addressing current challenges in viticulture as they limit the use of herbicides while increasing potential ecosystem services. Scientific literature barely considers the importance of service crop management to reach trade-offs between ecosystem services and disservices. This study evaluates during a three-year experiment, 6 service crop termination strategies for winter service crops, combining two service crops termination periods (early termination in February vs. termination at grapevine budburst) and three termination methods (mower (M), mower + tillage (T), roller-crimper (R)). Service crop (biomass, C:N ratio, weeds, and mulch following termination), soil ( soil organic matter, microbial biomass, and water and nitrogen stocks), and grapevines (predawn leaf water potential, yield components, δ13C, yeast assimilable nitrogen in juice, and pruning weight) were monitored from 2019 to 2022. Allowing service crops to develop until the budburst of the vine resulted in a two to three-fold increase in biomass compared to early destruction. Termination involving soil tillage was the most effective method, as treatments destroyed early with soil tillage exhibited almost no regrowth. Soil tillage termination led to the lowest biomass of weeds at the grapevine flowering two years out of three, and prevented the regrowth of certain sown plants, especially Poaceae. The roller was less effective in destroying service crop species but was the best method for maintaining plant residues on the soil surface. A higher soil microbial biomass was observed with termination at budburst, combined with no-till termination methods. Termination involving soil tillage was notably more effective in stopping service crop transpiration, increasing soil water stocks and improving grapevine water status. In 2020 and 2022, soil inorganic nitrogen stocks were almost 4 times higher in the T treatments compared to the other two termination methods, achieving a level of approximately 61 kg ha−1 that closely corresponds to the annual nitrogen requirements of grapevines. The yeast-assimilable nitrogen (YAN) content in grape juice mirrored this trend. Pruning weight varied significantly between different termination methods, with T treatments exhibiting a higher pruning weight per vine in comparison to R and M treatments. In general terms, the T treatment had a significantly higher number of bunches, the M treatment had the lowest, and the R treatment exhibited intermediate values. Overall, the average grapevine yield ranged from 7.25 to 13.7 t ha−1, corresponding to 52–98 hL ha−1 (with 4000 vines ha−1, 140 kg hL−1). This level of production may be accepted for Protected Designations of Origin that limit grapevine yield to 40 or 60 hL ha−1, but it could be a limitation for Protected Geographical Indications, which permit 90 hL ha−1, or unlabeled productions without yield limitations. Given the Mediterranean climate context, with rising frequencies of dry winters due to climate change, termination involving soil tillage appears to be the least risky strategy to preserve grapevine vigor and production while improving soil-based ecosystem functions. However, this might be contingent on the targeted yield and wine valuation.

Irrigation decreases flower cover and beneficial arthropod abundances in Mediterranean vineyards

Over the last decades, the use of irrigation in vineyards has grown exponentially in response to climate change. In the Mediterranean region, irrigation is the most widely used method of preventing water stress and high sugar content in grapes. However, little is known about potential irrigation effects on biodiversity. This study aims to understand the effect of irrigation on inter-row vegetation, on the abundance of beneficial arthropods and on the predation of pest insects. In the Luberon region of South-Eastern France, nine irrigated and nine non-irrigated vineyards were analysed. Drip irrigation was applied only during the two driest months of the growing season. We found lower flower cover in irrigated vineyards but no difference in species richness and total vegetation cover. Similarly, abundances of several beneficial arthropods were directly affected by irrigation, such as crab spiders, ladybirds, ladybird larvae and parasitic wasps. Structural equation modelling (SEM) revealed that negative irrigation effects on these arthropods were mediated by negative effects on flower cover. Predation rates were also lower in irrigated vineyards but only during daytime. Grapevine yield was not affected by irrigation. Experiments manipulating water availability under controlled conditions may help to understand this surprisingly strong effect of irrigation on flower cover and beneficial arthropod abundance.

The response of yield, number of clusters, and cluster weight to meteorological factors and irrigation practices in grapevines: A multi-experiment study

Knowledge of the yield components of wine grapevines is essential to achieve target production and effectively design vineyard management. Therefore, it is necessary to map and analyze the factors that control the yield components to optimize wine production and profitability. The objective of this study was to identify the ranked effects of environmental and agrotechnical factors (e.g., meteorological, physiological, vegetative, and irrigation) on grapevine yield, number of clusters, and cluster weight, and to quantify their patterns. To achieve this objective, a multi-experiment database was used, assembling data collected during four long-term irrigation experiments including different varieties and diverse climatic regions across Israel. First, a paired analysis of the yield components was conducted to define the relationships among them. Then, prediction models for the three variables (i.e., yield components) were designed using the support vector machine (SVM) algorithm to explore the ranked effects and patterns of the controlling factors. Validation was conducted using a test set, consisting of 20% of the dataset. The relationships between yield and cluster weight (0 < r < 0.73) and between yield and the number of clusters were always positive (0.67 < r < 0.77), while negative relationships were found between cluster weight and number of clusters (-0.61 < r < 0). The accuracy of the prediction models was high, with mean absolute errors (normalized to the range) ranging between 4.1%-8.11%. The most dominant factors affecting yield components were cumulative leaf area index, accumulated growing degree days (GDD), cumulative irrigation, and evapotranspiration. Leaf area showed an optimum point, below and above which the values of the yield components decrease; GDD negatively affected yield and cluster weight but had a positive effect on the number of clusters; irrigation was positively associated with yield components but leveled out above 348-395 mm per season. Reference evapotranspiration had a negative effect on yield and cluster weight, and a generally positive effect on the number of clusters. Utilizing data from multiple experiments and applying multivariate analysis, allow to define general patterns of relationships and interactions between controlling factors and yield components. Extracting this knowledge from the data and managing the growing amounts of information can be achieved through complex modeling and the implementation of standard protocols for data collection and monitoring.

Potassium fertigation and organic fertilisation in ‘Syrah’ grape in Northeastern Brazil: yield, must characteristics and phenolic compounds

The effect of both potassium and organic fertilisation on grape yield and must composition originating from wine grapevines cultivated in the São Francisco river basin, in the semi-arid region of Northeastern Brazil, is not well known. Since soils from that region usually have low organic matter content, we hypothesise that soil application of organic fertiliser and potassium application through drip irrigation enhances the availability of this nutrient in the soil, and it influences grape yield and quality. Hence, five doses of potassium (0, 20, 40, 80 and 160 kg ha-1) applied through a drip irrigation system and two doses of goat manure as organic fertiliser applied into the soil (0 and 7.5 m3 ha-1) after pruning were evaluated concerning yield and berry quality of grapevine ‘Syrah’ over four growing seasons (April 2013 to July 2015) in Petrolina, state of Pernambuco, Brazil. The experimental design was randomised blocks with 5 replications. We evaluated yield (t ha-1), weight of 100 berries (g), must volume (mL), total soluble solids (°Brix), pH and total titratable acidity (‰), K, Mg and Ca contents and phenolic compounds (total polyphenols, anthocyanins and flavonoids). The increasing application of potassium at the different doses of organic fertiliser did not alter the crop yield, except in the second season. Nonetheless, K concentration in grape must was influenced in the four growing seasons, with higher values at fitted K2O doses by polynomial regression of 83.62 kg ha-1 (first season), 101.25 kg ha-1 (second season), 120.00 kg ha-1 (third season) and 77.99 kg ha-1 (0 m3 ha-1 organic fertiliser) and 96.07 kg ha-1 (7.5 m3 ha-1 organic fertiliser) in the fourth season. The addition of increasing doses of potassium interfered with the wine grape quality, which is an important factor to be considered in relation to its acidity. Organic fertilisation did not affect the most quality characteristics of the grapes.

Evaluation of canopy fraction-based vegetation indices, derived from multispectral UAV imagery, to map water status variability in a commercial vineyard

AbstractWater stress is a major factor affecting grapevine yield and quality. Standard methods for measuring water stress, such as midday stem water potential (ΨSWP), are laborious and time-consuming for intra-block variability mapping. In this study, we investigate water status variability within a 2.42-ha commercial Cabernet Sauvignon block with a standard vertical trellis system, using remote sensing (RS) tools, specifically canopy fraction-based vegetation indices (VIs) derived from multispectral unmanned aerial vehicle (UAV) imagery, as well as standard reference methods to evaluate soil and plant water status. A total of 31 target vines were monitored for ΨSWP during the whole growing season. The highest variability was at véraison when the highest atmospheric demand occurred. The ΨSWP variability present in the block was contrasted with soil water content (SWC) measurements, showing similar patterns. With spatial and temporal water stress variability confirmed for the block, the relationship between the ΨSWP measured in the field and fraction-based VIs obtained from multispectral UAV data was analysed. Four UAV flights were obtained, and five different VIs were evaluated per target vine across the vineyard. The VI correlation to ΨSWP was further evaluated by comparing VI obtained from canopy fraction (VIcanopy) versus the mean (VImean). It was found that using canopy fraction-based VIs did not significantly improve the correlation with ΨSWP (NDVIcanopyr = 0.57 and NDVImeanr = 0.53), however fractional cover (fcover) did seem to show a similar trend to plant water stress with decreasing canopy size corresponding with water stress classes. A subset of 14 target vines were further evaluated to evaluate if additional parameters (maximum temperature, relative humidity (RH), vapour pressure deficit, SWC and fractional cover) could serve as potential water stress indicators for future mapping. Results showed that the integration of NDVIcanopy and NDREmean with additional information could be used as an indicator for mapping water stress variability within a block.

Nitrogen retrieval in grapevine (Vitis vinifera L.) leaves by hyperspectral sensing

Nitrogen (N) is a critical macronutrient that directly affects grapevine yield and quality but is also highly mobile in soil and can cause environmental contamination when over-applied. Monitoring leaf N content is useful for assessing vine N status and thereby improving N management plans, and the ability to assess N by remote sensing is desirable. Remote sensing technology has been utilized for retrieving N in agronomic crops since the 1990s. However, remote sensing has not been widely adopted for N management mainly due to variability in spectral patterns that emerge when training a model on one dataset and then applying it to a different dataset. Differences in environmental conditions, phenological stages, and plant varieties contribute to variability. This study aimed to understand the major factors limiting the generalizability of N-level retrieval algorithms in grapevine: the impact of leaf age and how calibrating nitrogen content, using either leaf dry mass (Nmass) or leaf area (Narea), influence the outcomes. This study also compares the performance among five major N retrieval approaches. We used spectral data from a hand-held hyperspectral sensor measuring wavelengths from 350 to 2500 nm from 664 individual leaf samples obtained from two grapevine varieties on three different sampling campaigns. Our findings indicate that while machine learning and chemometric approaches offer high accuracy levels (R2 = 0.78), the physical modeling approach utilizing the PROSPECT radiative transfer model (RTM) is capable of consistently retrieving N independent of specific dataset conditions and with an acceptable level of accuracy (R2 = 0.45) while using only 50% of the hyperspectral data. The estimation of Nmass using Proteinmass, which was calculated from Proteinarea retrieved by RTM and ground truth LMA, demonstrates a high potential for consistent retrieval of Total N (TN) in grapes. We also found that while calibrating a model by Narea can eliminate the negative impact of leaf age on prediction accuracy, Nmass still performed better in four out of five approaches tested. This study shows that a hybrid model that combines machine learning and RTM can alleviate the impact of leaf age on prediction accuracy while reducing 50% of spectral bands required and maintaining an acceptable level of accuracy (R2 = 0.54).

Prediction of physical attributes in fresh grapevine (Vitis vinifera L.) organs using infrared spectroscopy and chemometrics

Spectra obtained from fresh grapevine organs provide information on chemical composition but could also contain valuable information on the morphological and physical attributes. The prediction of grapevine organs physical attributes using infrared spectroscopy is explored for the first time in this study. Near infrared spectroscopy (NIR) using a solid probe (NIR-SP) and a rotating integrating sphere (NIR-RS) and mid infrared (MIR) were used to obtain spectra from fresh and intact grapevine shoots, leaves, and berries. Linear partial least squares (PLS) and non-linear least absolute shrinkage and selection operator (LASSO), and extreme gradient boost (XGBoost) were implemented to predict relevant physical attributes in grapevine organs. NIR-RS using XGBoost showed coefficients of determination in validation (R2val) of 91.01% and root mean square error of prediction (RMSEP) of 0.71 mm (6.80%) for berry diameter. Shoot diameter was predicted at R2val of 62.08% and RMSEP at 0.82 mm (12.75%) using NIR-RS with LASSO regression. Monitoring these attributes throughout the growing season can lead to important viticultural information on grapevine yield, growth, and health.

Effect of integrate water shortage and soil conditioners on water productivity, growth, and yield of Red Globe grapevines grown in sandy soil

Abstract Water-deficit problem in Egypt due to the scarcity of water resources and climatic changes causes significant stress on all crops such as grapevines. Using soil conditioners like superabsorbent polymer (SAP) and Bentonite (BENT) can reduce water problems due to their abilities to store more water and improve the physical and chemical characteristics of soil. A field experiment with a completely randomized block design was carried out in three replicates at a private farm in Minia Governorate, Egypt to assess the influence of SAP and BENT on growth, yield, and water productivity (WP) of Red Globe grapevines as well as some physical and chemical properties of soil under water deficit regime (75 and 50% of water requirement) and full irrigation 100% of water requirement (control) during 2021 and 2022 seasons. The vines were 13 years and irrigated by a drip irrigation system in sandy soil. The studied soil was treated with different doses of SAP (250 and 500 g/vine) and BENT (200 and 400 g/vine). The obtained results showed that reducing irrigation to 75 and 50% of the water requirements led to significant decrease in vegetative growth metrics, readings for SPAD, leaf nutrients (N, P, and K), yield and its constituents as well as the physical and chemical properties of the berries compared to full irrigation. Adding SAP and BENT significantly increase the aforementioned characteristics under water deficit conditions. Application of SAP and BENT was the most effective way to mitigate the negative effects of water shortage on growing Red Globe grapes in sandy soil. SAP gave better results than BENT. Thus, applying superabsorbent 500 g/vine with deficit irrigation 75% of water requirements was a successful treatment in producing an economical yield and berries with fairly high quality and had a positive effect in enhancing WP as well as it proved to be a promising method to improve sandy soil characteristics.

Effect of foliar spraying with Seaweed Extract (Chlorella vulgaris) and Nano fertilizers on growth, yield and fruit quality of Flame Seedless grapevines

Effect of foliar spraying with Seaweed Extract (Chlorella vulgaris) and Nano fertilizers on growth, yield and fruit quality of Flame Seedless grapevines

Ameliorative Effect of Yeast and Gamma Irradiated Licorice Extracts on Growth, Yield, Fruit Quality and Nutrient Content of Red Globe Grapevine

Ameliorative Effect of Yeast and Gamma Irradiated Licorice Extracts on Growth, Yield, Fruit Quality and Nutrient Content of Red Globe Grapevine

Effect of foliar spraying with seaweed extract (Halamphora coffeaeformis) and Nanosize fertilizer on growth, yield, and fruit quality of Flame Seedless grapevines

Effect of foliar spraying with seaweed extract (Halamphora coffeaeformis) and Nanosize fertilizer on growth, yield, and fruit quality of Flame Seedless grapevines