ISHS Acta Horticulturae 493: I ISHS Workshop on Water Relations of Grapevines
SAP FLOW MEASUREMENTS ON DIFFERENT SCION VARIETIES |
| Authors: | M. Porten, F. Manty |
| Keywords: | Granier, sap flow, White Riesling, Pinot noir, Osteiner, water consumption, leaf area, transpiration |
| Abstract:
Sap flow of varieties White Riesling, Pinot Noir and Osteiner was measured in the field over a period from 25 June - 2 October 1995. There was clear response in sap flow to climatic variables such as temperature and solar radiation. Different varieties behaved similarly with regard to their environmental response. However, large differences between the varieties in cumulative sap flow per unit leaf area over the entire measuring period were observed. During the entire period of 98 days Pinot Noir had a water use of 59,8 l / m2 of leaf area. The varieties White Riesling an Osteiner used 36,3 and 30,8 l/m2 of leaf area respectively during the same period. The differences in water use between the varieties were also apparent during a short 12-day period and for single day measurements. The differences in water use seem to be variety specific and genetically determined. Therefore, there is scope for the breeding of scion varieties that are drought tolerant and suitable for planting on drought affected hill sides. Müller-Thurgau (1892) described transpiration as one of the basic principles of plant life. In This context he mentioned the importance of transpiration for the plant's "temperature regulation by cooling". This is of particular importance in relatively warm climates to which Vitis vinifera is indigenous. Under very dry conditions water deficits can become detrimental to vine growth, yield and fruit quality performance. In many of the traditional wine growing sites in Germany lack of water is a regular occurrence. Reasons are, low rainfall of 500 mm or less, of which only a small proportion is received during the growth period; shallow and often stony soils with a low water holding capacity, often located on steep slopes of a southern aspect. Water for irrigation purposes is normally not available. One option to overcome some of these limitations in water availability is the use of drought tolerant scion varieties (Becker 1979). The question arises which grapevine variety is most adaptable to dry conditions. There are only few reports in the literature that specifically investigated varietal differences with regard to vine transpiration (Bosian 1940; Bravdo, Lavee, Samish 1972; Füri, Kozma 1977; Korbinger, Kliewer, Lagier 1984; Rühl, Savelkouls 1986). The objective of this work was to determine whole vine water use of three grapevine varieties throughout the latter part of the growing season. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
