Search

Small berries are considered to produce the best red wines as berry size determines the skin to pulp ratio and may affect wine composition. However, contrasting results have been reported about this postulate. In this context, the aim of this work was to assess the influence of berry size on grape compositional attributes in ‘Tempranillo’ grapevines under different irrigation, crop load and defoliation regimes. Grapes were collected from different experiments performed during three years in a ‘Tempranillo’ vineyard (Valencia, Spain). Grape size distribution was assessed and several traits were measured for each size category: number of seeds, seed and skin weight, total soluble solids, titratable acidity, pH, total phenolic index and anthocyanin concentration. Berry size exerted a significant effect on grape composition; smaller berries having higher sugars and anthocyanins concentrations. However, irrigation, crop load and defoliation also affected these compositional traits, producing greater berries with similar traits than those smaller, but coming from rain-fed and not defoliated treatments. Depending on the field practices applied, grape compositional attributes can be modulated for a given berry size. Therefore, wineries can use berry size classification for selecting those from a given size for making different wine styles.

Under semiarid and warm climates, field practices for climate change adaptation have to be defined in order to modulate grape composition according to the desired wine styles. Under this context, the present study investigated several viticulture practices in cv. Macabeo for Cava production. The experiment was carried out over 3 years in a commercial vineyard located in the province of Valencia (eastern Spain). The techniques tested were (i) vine shading, (ii) double pruning (bud forcing), and (iii) the combined application of soil organic mulching and shading, all of them tested against a control. Double pruning significantly modified phenology and grape composition, improving the wine alcohol-to- acidity ratio and reducing the pH. Similar results were also achieved by shading. However, the shading strategy did not significantly affect yield, unlike double pruning, which reduced vine yield even in the year following its application. Shading alone or in combination with mulching significantly improved the vine water status, suggesting that these techniques can also be used to alleviate water stress. Particularly, we found that the effect of soil organic mulching and canopy shading on stem water potential was additive. Indeed, all the techniques tested were useful for improving wine composition for cava production, but double pruning is only recommended for premium Cava production. [ABSTRACT FROM AUTHOR]

The sustainability of woody crop agroecosystems requires continued improvements to water, nutrient and soil management. In this work, the combination of resource availability or fertigation dose with soil management practices was tested in a 2 × 2 factorial design in a drip irrigated young almond orchard. The fertigation doses were: the farmer supply at 60% of crop evapotranspiration and full nutrient requirements and the half-farmer supply at 30% of crop evapotranspiration and half nutrient requirements. The soil management practices were: bare soil and cover crops in the inter-row (mixture of grasses and legumes). Tree growth, yield, water and nutrient status, and cover crop biomass and nutrient status were determined, as well as inter-row soil C and N concentration. Results showed that the effect of resource availability was independent of soil management and vice versa. The half farmer treatment reduced tree vegetative growth and yield compared to farmer treatment, due to a negative effect on the water status, without observing a decrease in the concentration of nutrients in leaves or fruit. Trees with cover crop also reduced growth and yield compared to bare soil management. This was due to a nutritional competition, mainly of Ca, Fe, Mn and Zn, rather than to a decline in tree water status. Cover crops sequester up to 1 t/ha/year of carbon but do not increase soil organic carbon, nor soil total nitrogen. Cover crops proved to be efficient in reducing soil nitrate concentration in the topsoil and therefore has potential to prevent its leaching. Deficit fertigation and the use of cover crops can be effective practices to preserve and save water and nutrient resources in Mediterranean agroecosystems, but should be established with caution so as not to compromise the profitability of the orchard. [ABSTRACT FROM AUTHOR]

Selecting genotypes with a better capacity to respond and adapt to soil water deficits is essential to achieve the sustainability of grapevine cultivation in the context of increasing water scarcity. However, cultivar changes are very poorly accepted, and therefore it is particularly interesting to explore the intracultivar genetic diversity in water use efficiency (WUE). In previous studies, the cultivar "Grenache" has shown up to 30% variability in WUE. This research aimed to confirm the intracultivar variability and to elucidate the traits underlying this variability in the response to a water deficit by analyzing the growth rates, water relations, osmotic potential, leaf morphology, leaf gas exchange and carbon isotope discrimination in nine "Grenache" genotypes grown in pots during two seasons. The results showed lower differences in WUE and carbon isotope ratio than in previous field studies, but fairly good consistency in genotype ranking. Leaf mass area and osmotic potential did not underlie differences in stem water potential and in stomatal conductance. Overall, stomatal regulation and photosynthetic capacity seem to underlie differences in WUE among genotypes with an important environmental influence. These results confirm the ability to select clones with higher WUE and present an opportunity for the genetic improvement of WUE in grapevines. [ABSTRACT FROM AUTHOR]

The use of more salt stress-tolerant vine rootstocks can be a sustainable strategy for adapting traditional grapevine cultivars to future conditions. However, how the new M1 and M4 rootstocks perform against salinity compared to conventional ones, such as the 1103-Paulsen, had not been previously assessed under real field conditions. Therefore, a field trial was carried out in a young 'Tempranillo' (Vitis vinifera L.) vineyard grafted onto all three rootstocks under a semi-arid and hot-summer Mediterranean climate. The vines were irrigated with two kinds of water: a non-saline Control with EC of 0.8 dS m-1 and a Saline treatment with 3.5 dS m-1. Then, various physiological parameters were assessed in the scion, and, additionally, gene expression was studied by high throughput sequencing in leaf and berry tissues. Plant water relations evidenced the osmotic effect of water quality, but not that of the rootstock. Accordingly, leaf-level gas exchange rates were also reduced in all three rootstocks, with M1 inducing significantly lower net photosynthesis rates than 1103-Paulsen. Nevertheless, the expression of groups of genes involved in photosynthesis and amino acid metabolism pathways were not significantly and differentially expressed. The irrigation with saline water significantly increased leaf chloride contents in the scion onto the M-rootstocks, but not onto the 1103P. The limitation for leaf Cl- and Na+ accumulation on the scion was conferred by rootstock. Few processes were differentially regulated in the scion in response to the saline treatment, mainly, in the groups of genes involved in the flavonoids and phenylpropanoids metabolic pathways. However, these transcriptomic effects were not fully reflected in grape phenolic ripeness, with M4 being the only one that did not cause reductions in these compounds in response to salinity, and 1103-Paulsen having the highest overall concentrations. These results suggest that all three rootstocks confer short-term salinity tolerance to the scion. The lower transcriptomic changes and the lower accumulation of potentially phytotoxic ions in the scion grafted onto 1103-Paulsen compared to M-rootstocks point to the former being able to maintain this physiological response in the longer term. Further agronomic trials should be conducted to confirm these effects on vine physiology and transcriptomics in mature vineyards. [ABSTRACT FROM AUTHOR]

The selection of genotypes best adapted to environmental conditions has traditionally focused on agronomic and grape composition parameters. However, to classify the genotypes most adapted to climate change conditions, the aim must be to focus on the ecophysiological responses that will ultimately determine their performance. The variability in water use efficiency of 13 Grenache genotypes over three‐seasons was assessed under field conditions at leaf, grape and plant level. Results showed a significant effect of genotype at all three levels, and despite the large interannual variability there was a remarkable consistency among levels. Furthermore, using genotype‐specific regressions it was possible to identify significant differences in the intrinsic water use efficiency response of each genotype as a function of the vine water status. The relationship between net photosynthesis and stomatal conductance, as well as carbon isotope discrimination in grapes, were also confirmed as reliable physiological indicators for selecting grapevine genotypes to future environmental conditions. Therefore, the proposed multi‐level methodology was useful to quantify the intracultivar variability and the identification of more and less efficient genotypes within Grenache. [ABSTRACT FROM AUTHOR]

Postharvest deficit irrigation (DI) strategies have been proven to advance bloom, harvest dates and economic return in loquat ‘Algerie’ trees because an early harvest results in higher loquat fruit prices. This fact poses the question of whether postharvest DI strategies could have a similar effect on more precocious cultivars than cv . Algerie, providing thus a more profitable option to farmers. In this work, the response of an early- and intermediate-maturing loquat cultivars ( cv . Cardona and Algerie, respectively) to a summer early (DI early ) and late (DI late ) DI strategy was assessed in two parallel studies during three consecutive years. The effects of the DI early and DI late strategies on bloom date, percentage of fruit picked at harvest per picking date and yield of both loquat varieties were studied. Moreover, fruit quality of cv . Cardona at harvest was also assessed. Plant water status was monitored by midday stem water potential (Ψ stem ) measurements. Results showed that DI early and DI late strategies advanced bloom in both cultivars although a higher effect was observed with the DI early than with the DI late treatment. Water restrictions did not increase the percentage of fruit picked at any of the picking dates and did not affect yield or fruit quality in the early-maturing cultivar. In ‘Algerie’ trees, a higher percentage of fruit was generally picked during the first picking dates in the DI early and DI late treatments than in the control although differences were only statistically significant during the last experimental season. Yield was significantly higher in ‘Algerie’ DI late trees than in control or DI early trees two out of the three experimental seasons. Overall, results showed that the DI early and DI late strategies tested here did advance bloom in the early-maturing cultivar but did not have an effect on the percentage of fruit picked per picking date at harvest. Nevertheless, the fact that substantial water savings (>30%) were obtained with no detrimental effect on yield presents the use of postharvest DI strategies as an interesting option to be followed in early-maturing cultivars for a more efficient crop production. [ABSTRACT FROM AUTHOR]

Water scarcity is one of the main limiting factors for grapevine cultivation in semiarid regions, which is increasing in a context of climate change. To face this challenge, it could be useful to consider plant water use efficiency (WUE) as new criteria in current and future breeding programs. Considering the relation photosynthesis/stomatal conductance (AN/gs) and d13C as selection targets, several long-term studies of WUE variability among grapevine cultivars, clones within a cultivar and rootstocks was carried out, considering field and pots experiments at different environmental and water availability conditions. Results showed a significant variation of WUE among cultivars according to the different stomatal regulation capacity under drought when comparing ancient and commercial cultivars. Moreover, up to 30% of clonal variability in WUE was found within Tempranillo and Grenache cvs, mainly under moderate water stress conditions. Although seasonal and environmental conditions affected this inter and intracultivar variability, a multilevel methodology analysis made it possible to rank genotypes by their WUE. Regarding rootstocks, some field and pot experiment comparing behavior of commercial and new lines of genotypes, showed both a variability in plant water status regulation and WUE under drought. This variability was clearly related with plant hydraulics capacity. All these results support the interest of exploring genetic resources to cope with the effects of climate change on viticulture considering WUE as a selection criteria for breeding programs. [ABSTRACT FROM AUTHOR]

• Water regime and climatic conditions affect aroma composition of "Muscat of Alexandria". • Negative relationships between total volatiles and vine yield were observed. • Pre-veraison water deficits increased glycosidycally-bound compounds. • No water stress during pre-veraison increased free compounds. • Seasonal effects predominated over those of water regimes on grape aromas. Irrigation effects in relation to the environmental conditions on grape aromas are still unknown. This study aims to clarify the effects of water regime on the aromatic composition of "Muscat of Alexandria" grapes under the semiarid climate conditions of eastern Spain and over three seasons. The relationships between total volatile composition in free and glycosidically-bound fractions, vine performance, and grape composition were also assessed. The watering treatments studied were: sustained deficit irrigation (SDI) at 50% of the estimated crop evapotranspiration (ET c); early deficit (EDI), where pre-veraison water deficit was imposed; late deficit (LDI), in which a water shortage was applied during post-veraison; and control (C), irrigated at 100% of ET c during the entire season. The effects of water regimes on volatile and glycosidically-bound composition were different between seasons due to the predominant effect of the environmental conditions on aromatic composition. The seasons with the greater yield were associated to a lower grape aromatic composition, however, this effect at the crop level was less pronounced in the most irrigated treatment. In drier seasons, irrigation delayed ripening and increased the terpene concentration of "Muscat of Alexandria" grapes, showing a high treatment and season interaction. Specific water regimes have the potential to buffer the effects of environmental conditions on the aromatic composition of "Muscat of Alexandria" grapes in a semi-arid climate, as the result of the complex relationships between climatic factors, vine performance and grape maturity. [ABSTRACT FROM AUTHOR]

• Mulching and no-tillage improved vine water status regardless of watering regime. • Alleviations of water stress resulted in decreases in grape phenolic composition. • Soil management and water regime caused interactive effects on water use efficiency. • Bulk density increased at the soil surface due to mulching and no-tillage. Optimizing water use in vineyards is crucial for ensuring the sustainability of viticulture in semi-arid regions, and this may be achieved by minimizing direct water evaporation from the soil through the use of mulching. In this context, the current study aimed at assessing the combined effects of the vine-row application of an organic mulch (vine prunings) and no-tillage under two water regimes on soil properties, plant water and nutritional status, yield and must composition of grapevine (Vitis vinifera L.) cv. Bobal grown under semi-arid conditions. For this purpose, a field experiment in a split-plot design was carried out for three years (2016–2018) in a mature Bobal vineyard located in Eastern Spain. Two soil management strategies (tillage and organic mulching with no-tillage) were assessed under two water regimes (rainfed and deficit drip irrigation) with four replications per combination. Vine responses were determined by measuring midday stem water potential, leaf nutrient concentrations, pruning weight, yield components and grape composition. Soil properties were assessed at the end of the experiment. Mulching and no-tillage positively affected vine water status under both water regimes, resulting in reductions in grape phenolic composition. Interactive effects of both water regime and soil management on water use efficiency were found. Regardless of soil management practice, irrigation increased yield and pruning weight when compared to rainfed conditions. Soil management had slight effects on vine nutritional status. At the end of the experiment, soil compaction increased and infiltration decreased as a consequence of mulching and no-tillage. Organic mulch and no-tillage improved vine water status, however, considering the final soil surface compaction and low water infiltration rate, longer-term studies are necessary to assess the sustainability of combining both practices. [ABSTRACT FROM AUTHOR]

Increasing water-use efficiency (WUE) is mandatory for more sustainable agricultural land use. Here we studied during three consecutive years in a nectarine ( Prunus persica L.) orchard the effects of placing 2 × 40 L coconut fiber substrate (S) bags per tree on the agronomic performance and WUE. Additionally, there were two regimes of watering, control (C), fulfilling 100% of the estimated crop evapotranspiration (ET c ) and a deficit (D) irrigation treatment, replacing the 65% of the ET c . Root colonization of the substrate, changes in the soil and substrate water content and temperature, tree water status (midday stem water potential), shoot growth (trunk diameter and tree volume), fruit yield and fruit quality compounds, were determined. Coconut substrate was colonized by the roots after two months from its installation, and after three years root dry weight in the substrate averaged 172 and 155 g per tree for the control and deficit irrigation treatments, respectively. During the first year, tree growth was enhanced in the C irrigation, while freezing temperatures during fruit set almost totally removed all fruits. In the second year, probably the abundant rainfall disguised the effect of the substrate on the yield parameters. However, this year and the next, deficit irrigation reduced fruit mean weight and delayed fruit harvest. In the third year, the substrate in the deficit irrigation treatment had a positive effect on fruit yield by increasing the number of fruits per tree in comparisons with deficit irrigation trees without substrate. The combination of deficit irrigation and substrate increased the WUE over the rest of the treatments but with no clear improvements in the tree water status. The results suggest that nectarine trees with deficit irrigation and substrate could be benefiting from a more efficient use of nutrients that further increases fruit set or prevent fruit drop. [ABSTRACT FROM AUTHOR]

Vineyards occupy large areas in many Mediterranean agroecosystems, in which their evapotranspiration is a major component of the water cycle. The correct determination of the actual crop evapotranspiration (ET a) is critical for accurate irrigation scheduling, allowing to match irrigation applications to crop water needs. This study was conducted to monitor the vineyard ET a and its partitioning into soil evaporation (E) and plant transpiration (T), under deficit irrigation and rainfed conditions, and to obtain the relationship between the estimated relative water stress coefficient (K s,r) and measured midday stem water potential (Ψ stem). A 2-year field experiment was carried out in a 'Monastrell' commercial vineyard located in Fuente Álamo (Albacete, SE Spain). Thermal infrared radiometers were deployed in both treatments, together with a weather station, to gather all the inputs required in the simplified two-source energy balance (STSEB) approach. Results showed that the accumulated ET a ranged between 183 and 253 mm for the irrigated treatment, and between 121 and 158 mm for the rainfed conditions. Canopy transpiration in the irrigation treatment almost double the value obtained in rainfed conditions for both years, and the ratio T/ET a increases around 8–9% in the irrigation treatment. The E component ranged from 21% for the irrigated treatment up to 50% for the rainfed treatment, confirming its importance in the vineyard water balance. A good linear relationship (r2 =0.650) was obtained between K s,r and Ψ stem , indicating the potential of using a surface energy balance approach in conjunction with plant radiometric temperature measurements to monitor the vines water status. Moreover, the rainfed treatment reduced the values of stomatal conductance (g s), transpiration (E l) and net photosynthesis (A N) compared to the irrigated treatment, whereas no increase in the intrinsic water-use efficiency (WUE i) nor the instantaneous water-use efficiency (WUE inst) was observed. The reported results will be useful for improving deficit irrigation scheduling techniques for 'Monastrell' red grapes. • Surface energy balance has the potential to monitor vine water status. • Transpiration doubles in the irrigation treatment versus rainfed conditions. • Water stress is well captured by the estimated relative water stress coefficient. • Irrigation increased yield but to a lesser extent increased transpiration. • Rainfed conditions did not increase the water use efficiency at the leaf level. [ABSTRACT FROM AUTHOR]