Guyot or pergola for dehydration of Rondinella grape

Abstract

AIM: Pergola veronese is the most important vine training system in Valpolicella area but Guyot in the last decades is diffusing. Rondinella is one of the three most important varieties to make Amarone wine. In this study we compared the response of Rondinella grape during postharvest dehydration from vines trained with Guyot or Pergola.

METHODS: Grapes were harvested at the same ripening stage but the grape production of Guyot and Pergola was quite different, higher in Pergola vines. Grape bunches were placed in commercial fruttaio and left to dehydrate with close-open system until reaching a weight loss of 30%. Samplings were done at 10, 20, and 30% weight loss. Berry juice enochemical analyses were performed with WineScanTM (Foss Italia) whereas the analyses of specific polyphenol compounds such as trans-resveratrol, quercetin-glucoside, and the monoglucoside anthocyanins were carried out by HPLC. Electronic nose was used to measure the juice headspace gas and GC/MS to analyze the specific VOCs (volatile organic compounds).

RESULTS: Not significant difference in the grape characteristics between the two samples were observed during dehydration; sugars increased at the same extent, about 30% in proportion with the weight loss. The acidity did not change and was similar between the two samples but malic acid initially decreased and then increased. FAN was much higher in Guyot sample at harvest and the difference was kept during dehydration, probably due to higher yield of Pergola. Guyot sample had a higher content in quercetin and monoglucoside anthocyanins while Pergola grapes had higher content in total polyphenols and total anthocyanins and specifically in trans-resveratrol and complexed anthocyanins. Electronic nose revealed a significant difference in grape must volatiles between the two samples which was validated by different concentration in VOCs. 

CONCLUSIONS

Guyot provide grapes with high content of free anthocyanins and quercetin while Pergola grapes have high content in trans-resveratrol and total anthocyanins that increased greater in Pergola than in Guyot. A significant difference in VOCs were measured which was validated by electronic nose

DOI:

Publication date: September 15, 2021

Issue: Macrowine 2021

Type: Article

Authors

Fabio Mencarelli

DAFE, UNIVERSITY OF PISA, ITALY,GREGORIO SANTINI, DAFE, UNIVERSITY OF PISA, ITALY  BRUNELLA CECCANTONI, SERENA FERRI, RAFFAELE CERRETA, ANDREA BELLINCONTRO, DIBAF, UNIVERSITY OF TUSCIA, VITERBO, ITALY  MARGHERITA MODESTI, LIFE SCIENCE INSTITUTE, SCUOLA S.ANNA, PISA  DANIELE ACCORDINI, CANTINA VALOPOLICELLA DI NEGRAR, NEGRAR (VR), ITALY

Contact the author

Keywords

grape dehydration, resveratrol, quercetin, training system

Citation

Related articles…

Assessment of climate change impacts on water needs and growing cycle on grapevine in three DOs of NE Spain

This study assessed the suitability of grapevine growing in three DOs (Empordà, Pla de Bages and Penedès) of Catalonia (NE Spain) over the 21st century. For this purpose, an estimation of water needs and agroclimatic and phenological indicators was made. Climate change impacts were estimated at 1 km pixel resolution using temperature and precipitation projections from several general circulation models (GCM) and two climate change scenarios: RCP 4.5 (stabilization scenario) and RCP 8.5 (worst-case scenario). Potential crop evapotranspiration (following FAO procedure) and a daily water balance considering soil water holding capacity were used to estimate actual evapotranspiration of vines and, finally, water needs. Dynamics would be similar in the three DOs studied although the magnitude of impact differs. Water needs would be 2 and 3 times greater (ranging from 0 to more than 1500 m3/ha) than current water needs at both climate change scenarios. Moreover, blooming date would advance from 3 to 6 weeks, harvest date from 1 to 2.5 months, resulting in growing cycles from 10 to 80 days shorter. It should also be noted that frost risk would decrease from 6 to 76%, the number of days with temperatures above 30ºC during ripening would rise from 48 to 500% and tropical nights (minimum temperature >20ºC) at ripening would increase from 28 to 150%, depending on the scenario and the DOs. The impacts of climate change in the three DOs could result in significant limitations for grapevine cultivation and wine production if adaptive strategies are not applied. This result could serve as a basis for the design of specific and particular adaptation strategies to improve and maintain vineyards in the DOs studied and could be extrapolated to similar DOs and regions.

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

The rootstock, the neglected player in the scion transpiration even during the night

Water is the main limiting factor for yield in viticulture. Improving drought adaptation in viticulture will be an increasingly important issue under climate change. Genetic variability of water deficit responses in grapevine partly results from the rootstocks, making them an attractive and relevant mean to achieve adaptation without changing the scion genotype. The objective of this work was to characterize the rootstock effect on the diurnal regulation of scion transpiration. A large panel of 55 commercial genotypes were grafted onto Cabernet Sauvignon. Three biological repetitions per genotype were analyzed. Potted plants were phenotyped on a greenhouse balance platform capable of assessing real-time water use and maintaining a targeted water deficit intensity. After a 10 days well-watered baseline period, an increasing water deficit was applied for 10 days, followed by a stable water deficit stress for 7 days. Pruning weight, root and aerial dry weight and transpiration were recorded and the experiment was repeated during two years. Transpiration efficiency (ratio between aerial biomass and transpiration) was calculated and δ13C was measured in leaves for the baseline and stable water deficit periods. A large genetic variability was observed within the panel. The rootstock had a significant impact on nocturnal transpiration which was also strongly and positively correlated with maximum daytime transpiration. The correlations with growth and water use efficiency related traits will be discussed. Transpiration data were also related with VPD and soil water content demonstrating the influence of environmental conditions on transpiration. These results highlighted the role of the rootstock in modulating water deficit responses and give insights for rootstock breeding programs aimed at identifying drought tolerant rootstocks. It was also helpful to better define the mechanisms on which the drought tolerance in grapevine rootstocks is based on.

Effects of graft quality on growth and grapevine-water relations

Climate change is challenging viticulture worldwide compromising its sustainability due to warmer temperatures and the increased frequency of extreme events. Grafting Vitis vinifera L.

Grapevine yield-gap: identification of environmental limitations by soil and climate zoning in Languedoc-Roussillon region (south of France)

Grapevine yield has been historically overlooked, assuming a strong trade-off between grape yield and wine quality. At present, menaced by climate change, many vineyards in Southern France are far from the quality label threshold, becoming grapevine yield-gaps a major subject of concern. Although yield-gaps are well studied in arable crops, we know very little about grapevine yield-gaps. In the present study, we analysed the environmental component of grapevine yield-gaps linked to climate and soil resources in the Languedoc Roussillon. We used SAFRAN data and IGP Pays d’Oc wine yields from 2010 to 2018. We selected climate and soil indicators proving to have a significant effect on average wine yield-gaps at the municipality scale. The most significant factors of grapevine yield were the Soil Available Water Capacity; followed by the Huglin Index and the Climatic Dryness Index. The Days of Frost; the Soil pH; and the Very Hot Days were also significant. Then, we clustered geographical zones presenting similar indicators, facilitating the identification of resources yield-gaps. We discussed the number of zones with the experts of IGP Pays d’Oc label, obtaining 7 zones with similar limitations for grapevine yield. Finally, we analysed the main resources causing yield-gaps and the grapevine varieties planted on each zone. Mapping grapevine resource yield-gaps are the first stage for understanding grapevine yield-gaps at the regional scale.