Assessing bunch architecture for grapevine yield forecasting by image analysis

Ad una prima analisi l’interesse dimostrato dal settore produttivo nei confronti della zonazione vitivinicola è da ricondursi al fatto che dopo i primi approcci puramente accademici

Context and purpose of the study. The wine industries face significant challenges from two highly detrimental viruses: leafroll and red blotch.

Seedless table grapes are greatly appreciated for fresh and dry consumption. There is also some interest in seedless winegrapes, because the combination of lower fruit set, smaller berries with higher skin/pulp ratio and looser bunches with the absence of seeds in crushed berries, a possible source of astringent tannins, might also have favorable effects on wine quality.
The gene VviAGL11 has been shown to play a central role in stenospermocarpy in Sultanina, but the molecular bases of other sources of stenospermocarpy as well as of parthenocarpy have not been clarified yet.

The mechanization of vineyard work originally led to a reduction in planting densities due to the lack of machinery adapted to the vineyard. The current availability of specific machinery makes it possible to establish higher planting densities. In this work, three planting densities (1.40×0.80 m, 1.80×1 m and 2.20×1.20 m, corresponding to 8928, 5555 and 3787 plants/ha respectively) were studied with four varieties autochthonous of Galicia (northwestern Spain): Albariño and Treixadura (white), Sousón and Mencía (red). The vines were trained in a vertical shoot positioning system using a single Royat cordon, and pruned to spurs with two buds each. Agronomic data (yield, pruning wood weight, Ravaz index) and oenological data in must were collected. The higher planting density (1.40×0.80 m) had no significant effect on grape yield per vine in white varieties, although production per hectare was much higher due to the greater number of plants. In red varieties, this planting density resulted in a significantly lower production per vine, compensated by the greater number of plants. In addition, it significantly reduced the Brix degree in the must of the Albariño, Treixadura and Sousón varieties, and increased the total acidity in the latter two and Mencía. It also caused an increase in extractable and total anthocyanins and IPT in red grapes. The effects of high planting density on grapes are of great interest for the adaptation of varieties in the context of climate change. In the future, it could be advisable to modify the limits imposed by the appellations of origin on the planting density of these varieties in order to obtain more balanced wines.

Fruity notes play a key role in the consumer’s appreciation of Bordeaux red wines. If literature provides a lot of knowledge about the nature of volatile compounds involved in this fruity expression, the sensory phenomena involving these compounds in mixture still need to be explored. Considering previous sensory works about the impact of esters and some overripening compounds, the goal of this work was to study the implication of perceptual interactions involving red wine odorant compounds of diverse origins and described as potentially affecting fruity aromatic expression.