Radiation-associated effects on regulated deficit irrigation management in grapevine cv. Cabernet Sauvignon

Climate change is exerting unprecedented pressure on global viticulture, altering precipitation patterns, intensifying drought events, and making efficient irrigation management a critical challenge for sustainable production.

The majority of soils used for wine and table grape production in South Africa are notoriously shallow, i.e. they are restricting root penetration.

Grapevine is one of the most world widespread fruit crops and is a valuable source for studying adaptive responses to environmental stress.

Wine colour is the first quality characteristic to be assessed, especially regarding red wines. Anthocyanins are very well known to be the main responsible compounds for red wine colour. Red cultivars can synthesize and accumulate anthocyanins in berry skin to express their colour. However, anthocyanin accumulation is often influenced by a series of factors, such as genetic regulation, phytohormones, environmental conditions and viticultural management.

Grapevine rootstocks have traditionally been chosen in order to manage scion vigour, soil pests and soil conditions. Riparia Gloire de Montpellier (RGM) has been in use since the turn of the 19th century, over 100 years and still a remarkably stable source of phylloxera (Daktulosphaeria vitifoliae Fitch) resistance. The original source material was probably collected near the Missouri/Mississippi river confluence, a mid-continental but more southerly location in the United States. It has been hypothesized that more northerly selections of V. riparia Michx might improve both fall acclimation rate and depth of the scion, thus mitigating late fall frost and midwinter freeze damage.