Terroir 2004 banner
IVES 9 IVES Conference Series 9 Phototropic and geotropic shoot orientation: effect on physiological, vegetative and reproductive parameters

Phototropic and geotropic shoot orientation: effect on physiological, vegetative and reproductive parameters

Abstract

[English version below]

On a étudié l’effet de l’orientation des rameaux sur les paramètres physiologiques, végétatifs et reproductif durant deux saisons de croissance (2002/2003 et 2003/2004) dans la région de Stellenbosch dans une vignoble du cépage Merlot sur 99R conduite en espalier et taillé à cordon coursonné. Les vignes étaient espacées 2.7 x 1.5 m. L’irrigation a été appliquée quand la baie avait la dimension d’un pois et à la véraison. La végétation a été manipulé pour avoir les rameaux sur le même cordon orientés une partie vers le haut (phototropiques) et l’autre vers le bas (géotropiques). 
L’orientation vers le bas a réduit la longueur et la surface foliaire du rameau principal et des entre coeurs. Quand le rameau est orienté vers le bas les entre coeurs sur le même rameau sont plus homogènes. Le potentiel hydrique foliaire et de tige à midi évalué sur la feuille basale et apicale était inférieur dans l’orientation vers le bas au confronte de l’orientation vers le haut. Cela était particulièrement prononcé pendant la période de maturation du raisin. L’activité photosynthétique des feuilles basale et apicale des rameaux orientés vers le haut était plus haute que celle des rameaux orientés vers le bas, probablement, à cause des conditions microclimatiques plus favorables. Le poids, le volume et la longueur des grappes n’ont pas été sensiblement influencés par orientation du rameau. L’orientation vers le haut a sensiblement augmenté le glucose et l’acide tartrique des baies, le saccharose, l’acide malique et l’acide citrique étaient pratiquement inchangés. Moins d’eau a été perdue par les peaux des baies et cela a favorisé l’intensité de la couleur. Les résultats ont des implications importantes pour l’uniformité de composition de la baie et pour le choix du système de conduite dans les différents terroirs. 

The effect of shoot orientation during two growth seasons (2002/2003 and 2003/2004) on physiological, vegetative and reproductive parameters was investigated in the Stellenbosch area in a Merlot/R99 vineyard with a vertical trellising system. Vines were spaced 2.7 X 1.5 m in north-south orientated rows. Micro-sprinkler irrigation was applied at pea size berry and at vèraison stages. Observations were done on vines with a natural distribution and orientation of phototropically (upward) and geotropically (downward) shoots on the same cordon.
Soil water typically varied according to the progress in the season and with soil depth, decreasing towards the end of the season and increasing with depth. Geotropic orientation reduced the primary and lateral shoot length as well as the primary and secondary shoot leaf area. With phototropic shoot position, secondary shoots were more evenly distributed along the primary shoots. Basal and apical stem and leaf water potential was lower with geotropic orientation than with phototropic orientation. This was particularly pronounced during the ripening period. In spite of this, basal and apical leaf photosynthetic activity of the phototropically orientated shoots was higher than that of the geotropically orientated shoots, most probably because of more favourable microclimatic conditions experienced by the former. Bunch mass and volume and length of bunches were not significantly affected by shoot orientation. Phototropic orientation of shoots noticeably increased glucose and tartaric acid contents of the berries, whereas sucrose, malic acid and citric acid contents were virtually unaffected. In phototropically orientated shoots, less water was lost by the skins, favouring skin colour intensity. The results have important implications for bunch and berry composition uniformity and for trellising system selection on different terroirs

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

A. Pisciotta (1), R. Di Lorenzo (1) M.G.Barbagallo (1), C.G. Volschenk (2) & J.J. Hunter (2)

(1) Dipartimento di Colture Arboree, Università degli Studi di Palermo
Viale delle Scienze 11, 90128 – Palermo, Sicily, Italy
(2) ARC Infruitec-Nietvoorbij, Private Bag X5026, 7599 Stellenbosch, South Africa

Contact the author

Keywords

Merlot, shoot orientation, vegetative growth, photosynthetic activity, water potential, light interception, grape composition

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

Elevational range shifts of mountain vineyards: Recent dynamics in response to a warming climate

Increasing temperatures worldwide are expected to cause a change in spatial distribution of plant species along elevational gradients and there are already observable shifts to higher elevations as a consequence of climate change for many species. Not only naturally growing plants, but also agricultural cultivations are subject to the effects of climate change, as the type of cultivation and the economic viability depends largely on the prevailing climatic conditions. A shift to higher elevations therefore represents a viable adaptation strategy to climate change, as higher elevations are characterized by lower temperatures. This is especially important in the case of viticulture because a certain wine-style can only be achieved under very specific climatic conditions. Although there are several studies investigating climatic suitability within winegrowing regions or longitudinal shifts of winegrowing areas, little is known about how fast vineyards move to higher elevations, which may represent a viable strategy for winegrowers to maintain growing conditions and thus wine-style, despite the effects of climate change. We therefore investigated the change in the spatial distribution of vineyards along an elevational gradient over the past 20 years in the mountainous wine-growing region of Alto Adige (Italy). A dataset containing information about location and planting year of more than 26000 vineyard parcels and 30 varieties was used to perform this analysis. Preliminary results suggest that there has been a shift to higher elevations for vineyards in general (from formerly 700m to currently 850 m a.s.l., with extreme sites reaching 1200 m a.s.l.), but also that this development has not been uniform across different varieties and products (i.e. vitis vinifera vs hybrid varieties and still vssparkling wines). This is important for climate change adaptation as well as for rural development. Mountain areas, especially at mid to high elevations, are often characterized by severe land abandonment which can be avoided to some degree if economically viable and sustainable land management strategies are available.

Mesoclimate impact on Tannat in the Atlantic terroir of Uruguay

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.

Geospatial trends of bioclimatic indexes in the topographically complex region of Barolo DOCG

Barolo DOCG is an economically important wine producing region in Northwest Italy. It is a small region of approximately 70 km2 gross area. The topography is very complex with steep sloped hills ranging in elevation from below 200 m to 550 m. Barolo DOCG wine is made exclusively from the Nebbiolo grape. Bioclimatic indexes are often used in viticulture to gain a better understanding of broader climate trends which can be compared temporally and geographically. These indexes are also used for identifying potential phenological timing, growing region suitability, and potential risks associated with expected climatic changes. Understanding how topography influences bioclimatic indexes can help with understanding of mesoscale climate behaviour leading to improved decision making and risk management strategies. The average monthly maximum and minimum temperatures, the Cool Night Index, the Huglin Index, and the monthly diurnal range (from July to October) were calculated using data from 45 weather stations within a 40 km radius of the Barolo DOCG growing area between the years 1996 and 2019. Linear and multiple regression models were developed using independent variables (elevation, aspect, slope) extracted from a digital elevation model to identify significant relationships. Bioclimatic indexes were then kriged with external drift using independent variables that showed significant relationships with the bioclimatic index using a 100 m resolution grid. The maximum monthly temperatures and the Huglin Index showed consistent significant negative relationships with elevation in all years. The minimum monthly temperatures showed no relationship with elevation but in some months a small but significant relationship was observed with aspect. Due to the lack of a relationship between minimum monthly temperatures and elevation compared to the significant relationship between maximum monthly temperatures and elevation, monthly diurnal range had a negative relationship with elevation.

Influence of weather and climatic conditions on the viticultural production in Croatia

The research includes an analysis of the impact of weather conditions on phenological development of the vine and grape quality, through monitoring of four experimental cultivars (Chardonnay, Graševina, Merlot and Plavac mali) over two production years. In each experimental vineyard, which were evenly distributed throughout the regions of Slavonia and The Croatian Danube, Croatian Uplands,

Protected Designation of Origin (D.P.O.) Valdepeñas: classification and map of soils

The objective of the work described here is the elaboration of a map of the different types of vineyard soils that to guide the famers in the choice of the most productive vine rootstocks and varieties. 90 vineyard soils profiles were analysed in the entire territory of the Origen Denominations of Valdepeñas. The sampling was carried out in 2018 (June to October) by making a sampling grid, followed by photointerpretation and control in the field. The studied soils can be grouped into 9 different soil types (according to FAO 2006 classification): Leptosols, Regosols, Fluvisols, Gleysols, Cambisols, Calcisols, Luvisols and Anthrosols. A map showing the soil distribution with different type of soils has been made with the ArcGIS program. Regarding to the choice of rootstock, Calcisoles are soils with a high active limestone content, so the rootstocks used in these soils must be resistant to this parameter; Luvisols are deep soils with high clay content, so they will support vigorous rootstocks. Because the cartographic units are composed of two or more subgroups, with are associated in variable proportions, 9 different soil associations have been established; Unit 1: Leptosols, Cambisols and Luvisols (80%, 15% and 5% respectively); Unit 2: Cambisols with Regosols and Luvisols (40%, 30% and 30% respectively); Unit 3: Cambisols and Gleysols with Regosols (40%, 40% and 20% respectively); Unit 4: Regosols with Cambisols, Leptosols and Calcisols (40%, 30%, 15% and 15% respectively); Unit 5: Cambisols, Leptosols, Calcisols and Regosols (25% each of them); Unit 6: Luvisols with Cambisol and Calcisols (80%, 10% and 10% respectively); Unit 7: Luvisols and Calcisols with Cambisols (40%, 40% and 20% respectively); Unit 8: Calcisols with, Cambisols and Luvisols (80%, 10% and 10% respectively); Unit 9: Anthrosols. These study allow to elaborate the first map of vineyard soils of this Protected Designation of Origin in Castilla-La Mancha.