Plant and leaf responses to cycles of water stress and re-watering of 'Sangiovese' grapevine

Abstract The complex relationship between water and grapevine has been examined in several studies. The aim of this study was to understand the impact of water stress on photosynthesis, carbon-13 discrimination in leaves in different positions on the shoot, and the capacity of vines to recover from different levels of water stress intensity. The vine physiological responses to a water stress regimen followed by re-watering for two consecutive cycles was evaluated using potted 'Sangiovese' grapevines. The intensity and the duration of the water limitation affected the emergence and development of new leaves, but did not significantly affect leaf water potential. Leaf stomatal conductance and carbon assimilation during the first water-stress phase were reduced respectively by about 61% and 20%, while after the second water stress cycle both were lower than the initial values by 77% and 21%, respectively. After 1 day of re-watering, only the leaves located in the medial positions on the shoot showed a partial recovery of photosynthesis. After at least 2 days post-re-watering, the leaves located in the distal portion of the shoot showed a recovery of photosynthetic capacity. The results indicated that leaf position along the shoot, i.e., an indicator of leaf age, is an important variable in developing grapevine strategies in response to conditions of limited water availability

Effects of limited irrigation water volumes on near-isohydric ‘Montepulciano’ vines trained to overhead trellis system

The thermal increase, due to the changed climatic context, is leading to marked variations in the yield and quality of the grapes and causing an increase in the use of water resources in several viticultural areas. Nevertheless, in some environments, rainfalls are scarce and there is no water availability. In this study, we compared the impact of low water irrigation volumes (DI, replacement of 70% of crop evapotranspiration) with respect to non-irrigated vines (NI), on the physiological, yield and qualitative performances of near-isohydric variety ‘Montepulciano’, trained to overhead trellis system, which requires a high-water supply. The stomatal conductance and photosynthesis values, in basal and median leaves, were higher in DI vines. All NI leaves sufered water stress, showing in the youngest leaves (position 20 and 25 along the main shoot) higher carbon isotope discrimination (δ13C) (− 25.38‰ and 25–25.77‰, respectively). At harvest, DI vines showed yield higher of 30% and 33% than NI vines in 2005 and 2006, respectively, and 18% in 2007. In environments with prolonged water shortage and low water resource, near-isohydric ‘Montepulciano’ vines, trained to overhead trellis system and irrigated with limited volumes, determined a signifcant improvement of ‘vineyard efciency’ with a yield of 19.2 t/ha with respect to 13.4 t/ha of NI vines, ensuring also more sugar content (+31%), anthocyanin concentration (+13%) and polyphenolic substances (+8%) than NI vines

Effects of shading nets as a form of adaptation to climate change on grapes production: a review

Viticulture worldwide is threatened by the environmental modification caused by climate change. Higher temperature and atmospheric CO2 concentration determine an acceleration of the ripening process, which can be detrimental to wine quality. Hence, adaptation and mitigation strategies are necessary to reduce heat and water stress and improve the qualitative production levels. Amongst all the various techniques available, shading nets represent an interesting alternative for their effects on canopy microclimate and grape production. However, these effects vary strongly depending on the intensity of the shading treatment, the timing of its application, environmental conditions, and differences in cultivar response. The reduction in photosynthetic activity can improve water use efficiency and slow down the ripening process, preserving must acidity. Phenolic compounds, which benefit from light exposure for their synthesis, are negatively affected by shading, while aromatic composition can be improved by it. Vine reserve accumulation is reduced by the lower photoassimilates production. Photoselective nets, thanks to their colour, not only reduce light intensity but also change the quality of the light spectrum reaching the canopy, thus, determining specific responses in the plants

Vegetative development and berry growth in relation to heat accumulation in Sangiovese vines subjected to double pruning at three different times

The double pruning on Sangiovese based on pre-pruning and finishing in March, April and May applied over three years, induced a postponement of phenological phases, with repercussions on the vine vegetative and berry growth trends, with greater effects, according to the delay in the time of hand follow up during the season. The phenological development, the canopy and berry growth of Sangiovese, subjected to the three different finishing dates for the final pruning, were recorded during three years (2014-2016) and related to day of the year (DOY) and seasonal heat accumulation (growing degree days, GDD). A sigmoid growth model with high coefficient determination (R2 between 0.96 and 0.99), described shoot elongation and herbaceous berry growth, showing a temporal and thermal shift according to the finishing times. Despite the chronological delay, the vines revealed similar thermal necessities. Leaf area evolution of April and May finished vines showed 2 steps: a slow initial development followed by a rapid growth phase (91- 97cm2/GDD) beginning when shoots reached 7–10 leaves. GDD allowed to obtain simple models of vegetative development and berry growth of Sangiovese vines based on thermal evolution

Plant and leaf responses to cycles of water stress and re-watering of ‘Sangiovese’ grapevine

The complex relationship between water and grapevine has been examined in several studies. The aim of this study was to understand the impact of water stress on photosynthesis, carbon-13 discrimination in leaves in different positions on the shoot, and the capacity of vines to recover from different levels of water stress intensity. The vine physiological responses to a water stress regimen followed by re-watering for two consecutive cycles was evaluated using potted ‘Sangiovese’ grapevines. The intensity and the duration of the water limitation affected the emergence and development of new leaves, but did not significantly affect leaf water potential. Leaf stomatal conductance and carbon assimilation during the first water-stress phase were reduced respectively by about 61% and 20%, while after the second water stress cycle both were lower than the initial values by 77% and 21%, respectively. After 1 day of re-watering, only the leaves located in the medial positions on the shoot showed a partial recovery of photosynthesis. After at least 2 days post-re-watering, the leaves located in the distal portion of the shoot showed a recovery of photosynthetic capacity. The results indicated that leaf position along the shoot, i.e., an indicator of leaf age, is an important variable in developing grapevine strategies in response to conditions of limited water availability

Plant and leaf physiological responses to water stress in potted ‘vignoles’ grapevine

Several studies have investigated water relationships in grapevines, but the responses to water limitation on individual leaves developed in different shoot positions are scarce in the literature. To begin to fill-in this gap, we examined the adaptive responses of vines at the leaf level to varying amounts of water stress using young hybrid ‘Vignoles’ in a controlled growth chamber. We found that the reduction in water availability to 40% of daily evapotranspiration limited shoot and leaf growth, affecting leaf number, shoot elongation, and leaf area. After 2 days of water stress we observed young developing leaves (nodes six to eight from the shoot apex) to have drastically reduced stomatal conductance (gS, about 20 mmol H2O/m2/s) and net photosynthesis (Pn, 2 μmol CO2/m2/s). On the 4th day Pn in mature leaves (nodes 9 to 12 from the shoot apex) fell to values below 2 μmol CO2/m2/s. After 6 days, both Pn and gS stabilized at lower values with fluctuations related only to leaf position along the shoot axis. Young leaves revealed substantial enrichment of carbon-13 (13C) and high water-use efficiency suggesting a higher and faster adaptive capacity to water shortage conditions as compared with mature leaves

Innovative vine training system as a strategy for adaptation to climate change on Verdicchio

Grape quality is endangered by thermal increase caused by climate change. Hence, the necessity to find adaptation solutions moved research activities in the last few years towards experimenting innovative management techniques. In this trial an innovative training system, called High Cane, was compared with the traditional Guyot. High Cane trained vines showed lower photosynthetically active solar radiation values at the fruiting zone, a higher number of shoots per vine and total yield. At harvest, High Cane proved to have some effects in slowing down ripening, i.e. showing lower sugar content, higher titratable acidity and lower pH. The innovative training system is a candidate to be a valid strategy for the adaptation to the effects of climate change

Climate change effects on cv Montepulciano in some wine-growing areas of the Abruzzi region (Italy)

In this paper, we analyzed the climate change impact in some wine-growing areas of the Abruzzi region through the estimated dates of bud burst and the study of the relationships between some bioclimatic indexes with the beginning of harvest date of cv. Montepulciano, during the period 1974–2013. The earlier harvest date would seem mainly linked to the increase of heat summation in the period March–June. The break point of the time series of harvest date showed good correlation with the heat summation in the period from March to June. Climate change, occurred in European continent begun around 1980, would determine in the wine-growing areas of Abruzzi, a significant reduction in the growth cycle of the cv. Montepulciano, mainly due to the earlier harvest date, considering that there were no substantial changes in the estimated dates of bud burst