Grapevine productivity modelling in the Portuguese Douro Region

The table grape industry in Europe is undergoing significant changes. For instance, in Italy, the national register of vine varieties was established in 1969, and since then, many varieties of table grapes have been registered. In the first thirty years, from 1969 to 1999, 62 seeded and 24 seedless varieties were registered. In the subsequent period, from 2000 to the present day, 23 seeded varieties and 99 seedless varieties were registered.

Des expérimentations sur Gamay ont été réalisées en Beaujolais de 2000 à 2006 sur 10 parcelles d’AOC différentes. De nombreuses mesures ont été effectuées à différents stades (vigne, baies récoltées, vinification et bouteille avec ou sans vieillissement). Ces mesures sont également de natures différentes (données phénologiques, analytiques, dégustation). Des analyses de la composition des sols sont également disponibles.

The physical factors that influence the grape ripening include elevation, slope, aspect, potential global radiation, sun hours and soil type of the vineyards.

45 non irrigated vineyards distributed in the DO (Denomination) Pla i Llevant de Mallorca and the DO Binissalem Mallorca were used to investigate the characteristics of production and quality and their relationships certain environmental factors and cultural practices. The grape varieties investigated are autochthonous to the island of Mallorca, Manto Negro and Callet as red and Prensal Blanc as white. All plants were measured for four consecutive years in the main production and quality parameters. Among the environmental factors, the type of soil has been studied, more specifically its water retention capacity, the planting density, the age of the vineyard and the level of viral infection. The presence or absence of virus seems to have no effect on any component studied in the varieties studied. For the white variety Prensal Blanc age is negatively correlated with production and the number of bunches, nevertheless it does not cause any effect on the required quality parameters. However, for the red varieties Callet and Manto Negro, the age of the plantation is the variable that best correlates with the quality parameters, therefore the old vines should be the object of preservation by the viticulturists and winemakers in order to guarantee its contribution to the quality of the wines made with these varieties.

Grapevine faces multiple biotic and/or abiotic stresses, which are interrelated. Depending on their incidence, they can have a negative impact on the development and production of the plant, but also on its longevity, leading to vine dieback. One of the consequences of vine dieback on production is the increased replacement rate of dead or missing vines within a parcel.