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IVES 9 IVES Conference Series 9 Phenology and bioclimate of grapevine varieties in the tropical region of the São Francisco Valley, Brazil

Phenology and bioclimate of grapevine varieties in the tropical region of the São Francisco Valley, Brazil

Abstract

[English version below]

La région de la Vallée du São Francisco, situe à 9º S, est en train d’augmenter la production des vins fins les dernières années. La région présente climat du type tropical semi-aride (climat viticole à variabilité intra-annuelle selon le Système CCM Géoviticole : “très chaud, à nuits chaudes et à sécheresse forte à sub-humide” en fonction de la période de l’année dans laquelle le raisin est produit). La recherche objective la caractérisation de la phénologie et de la bioclimatologie des raisins de cuve dans la région. Ont été évalues 4 cépages avec différents niveaux de précocité – Syrah, Cabernet Sauvignon, Muscat Canelli et Schönburger, greffés sur IAC 572, vigne en premier cycle productif conduite en système pergola. Ont été évalués les stades phénologiques suivants selon le système d’Eichhorn & Lorenz : débourrement (B) – stade 05, floraison (F) – stade 23 et véraison (V) – stade 35. La date de récolte (H) corresponde à la récolte commerciale des raisins. La durée des sous-périodes phénologiques B-F, F-V, V-H et B-H a été calculée. Sur chacun des sous-périodes, ont été calculés 16 indices climatiques thermiques et hydriques. Les résultats de la Vallée du São Francisco ont été comparés avec les mêmes cépages d’une région de climat tempérée – la Serra Gaúcha (climat “tempéré chaud, à nuits tempérées, humide” selon le Système CCM Géoviticole), située à 29º S. Les résultats ont montré que la durée de la période B-H a été de 124, 123, 116 et 104 jours pour la Syrah, Cabernet Sauvignon, Muscat Canelli et Schönburger, tandis que dans la Serra Gaúcha, la durée a été de 158, 160, 160 et 138 jours, respectivement. Pour les caractéristiques bioclimatiques, dans la Vallée du São Francisco les températures moyennes de l’air de la période B-H ont varié entre 25,4 à 28,1 ºC, tandis que dans la Serra Gaúcha les températures ont varié entre 15,8 et 21,8 ºC. L’évapotranspiration potentielle, même si elle a présenté des moyennes journalières plus élevées dans la Vallée, ont été similaires pour le total dans la période B-H entre les 2 régions. Le rayonnement solaire global de la période B-H dans la Vallée du São Francisco a été inférieur si comparé avec la Serra Gaúcha. Ce résultat est lié surtout à la latitude (photopériode) et à la durée plus courte de la période B-H en condition tropicale. Le travail présente les indices bioclimatiques par cépage et sous-période, en comparant la région de baisse avec la région de moyenne latitude. On a conclu que le cycle végétatif de la vigne (B-H) est significativement plus court dans la Vallée du São Francisco (durée moyenne, pour les 4 cépages évalués, 37 jours inférieure que dans la Serra Gaúcha). Tel comportement est dû essentiellement à un raccourcissement de la période B-F (29 jours plus court en moyenne). On observe que le comportement phénologique de la vigne dans la Vallée du São Francisco, distinct par rapport à une région de climat tempérée, peut être expliqué surtout par le bioclimat particulier trouvé en zone tropicale.

The region of the São Francisco Valley, located at 9° S, has been increasing the production of fine wines during the last years. The region has a tropical semi-arid climate (viticultural climate with intra-annual variability according to the Geoviticultural CCM System : “very warm, with warm nights, very dry to sub-humid” depending on the period of the year in which the grapes are produced). The research aims at characterizing the phenology and bioclimatology of the region’s wine grapes. Four cultivars with different levels of precocity were evaluated – Syrah, Cabernet Sauvignon, Muscat Canelli and Schönburger, grafted on IAC 572, a vineyard in its first productive cycle, using the pergola as training system. The phenological stages bud burst (B) – stage 05, flowering (F) – stage 23 and veraison (V) – stage 35 were evaluated according to the system of Eichhorn & Lorenz. The date of the harvest (H) corresponds to the commercial grape harvest. The duration of the phenological subperiods B-F, F-V V-H and B-H has been calculated. For each subperiod 16 thermal and hydric climatic indices have been calculated. The results of the São Francisco Valley have been compared with the same cultivars from a temperate climate region – the Serra Gaúcha (“temperate warm, with temperate nights, humid viticulture climate” according to the Geoviticultural CCM System), located 29°S. The results have shown that the duration of the period B-H has been 124, 123, 116 and 104 days for Syrah, Cabernet Sauvignon, Muscat Canelli and Schönburger, while in the Serra Gaúcha the duration has been 158, 160, 160 and 138 days, respectively. As for the bioclimatic characteristics, the mean air temperature in the São Francisco Valley in the period B-H have varied from 25,4 to 28,1ºC, whereas in the Serra Gaúcha the temperatures have oscillated between 15,8 and 21,8ºC. The potential evapotranspiration, even when showing higher mean day values in the Valley, was similar in both regions during the whole period B-H. The global solar radiation for the period B-H in the São Francisco Valley was lower when compared with the Serra Gaúcha. This result is related especially to the latitude (photoperiod) and the shorter duration of the B-H period under tropical conditions. The study presents the bioclimatic indices by cultivar and subperiod, comparing the region of low with that one of mean latitude. It has been concluded that the vegetative cycle of the grapevine (B-H) is significantly shorter in the the São Francisco Valley (mean duration, for the 4 evaluated cultivars, 37 days less than in the Serra Gaúcha). Such behavior is a consequence, essentially, of a shortening of the period B-F (29 days shorter in the average). It can be stated that the phenological behavior of the grapevine in the São Francisco Valley, although distinct from a temperate climate region, can be understood above all by the particular bioclimate found in the tropical zone.

 

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

U. A. Camargo (1), J.Tonietto (1), F. Mandelli (1) and F.M. de Amorim (2)

U. A. Camargo (1)(1) Embrapa – National Center for Grape and Wine Research – Cnpuv, Rua Livramento, 515; 9570000-000 – Bento Gonçalves, Brazil
(2) Grant from CNPq/FINEP

Contact the author

Keywords

Wine grapes, tropical viticulture

Tags

IVES Conference Series | Terroir 2004

Citation

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