Terroir 2004 banner
IVES 9 IVES Conference Series 9 Partial rootzone drying (PRD): strategic irrigation management as viticultural tool affecting plant physiology and berry quality

Partial rootzone drying (PRD): strategic irrigation management as viticultural tool affecting plant physiology and berry quality


Partial rootzone drying (PRD) is an irrigation management technique designed to reduce water use in grapevines without a decline in yield, thereby increasing water use efficiency (WUE). The principle of PRD is to keep part of the root system at a constant drying rate to produce soil derived signals to above-ground plant organs to induce a physiological response resulting in viticultural effects. Major PRD effects include a reduced canopy size and greatly increased WUE with possible improvements in fruit quality. Experiments conducted under Australian conditions consisted of field-grown grapevines irrigated at variable rates to elucidate a true PRD effect. The effects of PRD on the assimilation and partitioning of C and N in grapevines are reported and the sustainability and economic potential of the PRD system are discussed. Major findings include the effects of PRD on grapevine physiology on the biochemical level where the source:sink relationship between plant organs influences dry matter accumulation and nitrogen assimilation that will influence fertilization needs. Finally, the effects of PRD on berry growth and quality are discussed, especially the accumulation of hexose, amino acids and inorganic ions such as K+, that may have an influence on wine quality.


Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article


Gerhard du Toit

Department of Viticulture and Oenology, Institute for Wine Biotechnology, Stellenbosch University, Victoria Street, ZA 7600 Stellenbosch, South Africa

Contact the author


IVES Conference Series | Terroir 2004


Related articles…

Application of nitrogen forms such as nitrate, urea, and amino acids effects on leaf and berry physiology and wine quality

Nitrogen (N) uptake by grapevine roots in forms like nitrate, ammonium, urea, or amino acids influences vegetative and generative growth, impacting grape quality and wine sensory profile. The study examined nitrogen’s influence on phenolic compounds in leaves, berries, and wine across different scales — hydroponics, soil culture, and vineyard trials. Nitrogen forms altered metabolite patterns in leaves and wine significantly, affecting aroma and flavor. Key nitrogen assimilation enzymes (NR, NiR, GS) in grapevine rootstocks responded to nitrogen forms and timing. Hydroponically grown rootstocks fertilized with various forms showed differences in enzyme expression and activity, suggesting rootstocks can assimilate amino acid glutamine (Gln).

Influence of a spontaneous cover crop on the vineyard and soil erosion under Mediterranean climate

Sixty five % of the agricultural area of the Basque Country located in the DO Ca Rioja corresponds to vineyards. More than 40% of it has an average slope greater than 10%, which makes it sensitive to erosive processes. Furthermore, it is foreseeable that extreme weather events (storms, hail, extreme heat and cold, etc.) will be favored due to climate change. Cover cropping can mitigate this risk, and therefore the objective of this work is to evaluate the impact that a vegetable cover has on the agronomic behavior of the vineyard, the quality of the grape and soil erosion. For this, a trial has been carried out with a Graciano variety vineyard with a slope between 10% -20% during the years 2020 and 2021. Conventional tillage management in the area has been compared (4-6 passes per year of tillage machinery) versus spontaneous vegetation cover management in the vineyard. This implies not tilling and allowing the grass of the land to colonize the range between the lines of vines, controlling their height through 1-3 mowing passes per year, always trying to affect the surface of the land as little as possible. The vegetative growth, yield and quality of the grape and wine was measured. Furthermore, erosion has been measured using Gerlasch boxes. The yield was lower in the second year of the trial in the cover crop treatment, but erosion was significantly reduced.

Lactiplantibacillus plantarum – A versatile tool for biological deacidification

Malolactic fermentation (MLF) is a secondary wine fermentation conducted by lactic acid bacteria (LAB). This fermentation is important in winemaking as it deacidifies the wine, converting L-malic acid into L-lactic acid and carbon dioxide, and it contributes to microbial stability. Wine pH is highly selective, and at pH below 3.5 generally only strains of O. oeni can survive and express malolactic activity, while under more favorable growth conditions above pH 3.5, species of Lactobacillus and Pediococcus may conduct the MLF. Among the LAB species Lactiplantibacillus plantarum strains have shown most interesting results under hot climate conditions, not only for their capacity to induce MLF, but also for their homo-fermentative properties towards hexose sugars, which makes them suitable for induction of MLF in high pH and high alcohol wines, when inoculated at the beginning of alcoholic fermentation.

Characterization and application of silicon carbide (SiC) membranes to oenology

After fermentations, the crude wine is a turbid medium not accepted by the consumer therefore, it needs to be filtered

Heat requirements for grapevine varieties is essential information to adapt plant material in a changing climate

Precocity for fruit ripening is a genetically determined characteristic that is highly variable from one cultivar to another. In traditional wine-growing regions of Europe, growers have used this property to adapt the vines to local climatic conditions in order to maximize terroir expression