Importance of canopy porosity into vineyard and the relationship with the grape maturity. Digital estimation method

摘要

In warm and dry climates, the use of porous systems should be required in order to allow a better leaf distribution inside the plant, causingudmore space in the clusters area and enhancing determined physiological processes so in the leaf (photosynthesis, ventilation, transpiration) asudin berry (growth and maturation). Plant geometry indexes, yield and must composition have been studied in three different systems: sprawludwith 12 shoots/m (S1); sprawl system with 18 shoots/m (S2) and vertical positioned system or VSP with 12 shoots/m (VSP1). Total leaf areaudincreases as the crop load does, whoever surface area depends on to two factors: crop load and the training system (VSPudvsud. sprawl), whichudcan provide differences in leaf exposure efficiencies. The main objective of this study was to validate digital photography measurementsudused to compare porosity differences among treatments and, as they affect plant microclimate and, therefore, yield and berryudquality. Also,udall previous studied indexes (LAI, SA, SFEr) tended to overestimate the relationship between exposed leaf surface and porosity of eachudtreatment, but the use of digital method proved to be an effective tool in order to assess canopy porosity. Results showed that not positionedudand free systems (sprawl) scored between 25ud-ud50% more porosity in the clusters area than the fixed vertical system (VSP), which resulted in audbetter plant microclimate for test conditions, mainly by improving the exposure of internal clusters and internal canopy ventilation. On theudother hand, higher crop load treatment (S2) showed a real increase in yield (16%) without any relevant change into must composition, evenudimproving total anthocyanin content into berry during ripening