Canopy Type and Its Effects on Photosynthesis and Fruit Quality of Cabernet Sauvignon Grapevines in Northern Mexico

Modification of canopy architecture is fundamental to productivity in grapevine. This research focused on evaluating the impact of canopy openness on photosynthetically active radiation, photosynthetic activity, and the physicochemical properties of fruit in Cabernet Sauvignon grapevines. A completely randomised design was used to compare open and closed canopies, with ten replicates per treatment (20 trees in total), during the vegetative growth period and after harvest. Key measurements included photosynthetically active radiation (PAR), daily light inte-gral (DLI), photosynthetic rate (PR), stomatal conductance (SC), intercellular CO2 concentration (IC), leaf area (LA), transpiration, ambient CO2 concentration, and temperature. Additionally, we assessed fruit quality parameters such as total soluble solids (TSS), glucose-fructose, total titratable acidity (TTA), pH, TSS/TTA, and total phenols (TP). significantly (p≤0.05) increased PAR, DLI, PR, IC, and LA, while after harvest, only PR and IC showed variation. Closed canopies increased CO2/H2O by 62.5%, while H2O/CO2 and temperature were higher in open canopies. Canopy openness increased contacts, gaps and visible sky and reduced leaf area index. Open canopy fruits showed higher TSS, glucose-fructose, pH, TSS/TTA and TP contents. Canopy openness is essential for improving light interception, photosynthetic efficiency and fruit quality in Cabernet Sauvi-gnon grapevine cultivated in northern Mexico.