Traditional viticulture is about managing a vineyard rather than individual grapevines. Practices such as irrigation, fertilisation, crop protection, and pruning are applied uniformly across a block. “I’m not saying it’s wrong,” remarks Prof Carlos Poblete-Echeverría, “but we want to move to something new to help growers improve.” Poblete-Echeverría is an associate professor in the Department of Viticulture and Oenology at Stellenbosch University (SU) and the Digital Agriculture Research Group Coordinator at the South African Grape and Wine Research Institute. His research focuses on developing and utilising new digital tools in viticulture and agriculture. He is interested in digital viticulture, defined as the application of new technologies to manage the spatial and temporal variability within vineyards, providing growers with valuable information to support optimal management.

A grape bunch contains berries and a rachis – two dissimilar tissues susceptible to different postharvest issues. A waxy coating protects berries from water loss, whereas the unprotected rachis is vulnerable to drying and browning. The rachis can also freeze below minus 1.0 °C, whereas berries freeze at minus 2.0–minus 3.0 °C. Grapes are non-climacteric fruit. Berries have a low respiration rate and, therefore, a low sensitivity to physiological disorders but a high sensitivity to senescence. Pre-optimally harvested grapes won’t ripen, but overmature grapes are more likely to suffer postharvest decay and internal browning. “Soluble solids are a measure of acceptability to the consumer – very high values could occur at a senescent stage of the tissue,” says Dr Juan Pablo Zoffoli, a postharvest physiologist in the Faculty of Agronomy and Natural Systems of the Pontifical Catholic University of Chile.