ISHS Acta Horticulturae 537: III International Symposium on Irrigation of Horticultural Crops
SAP FLOW MEASUREMENTS ON PHYLLOXERA INFESTED GRAPEVINES |
| Authors: | M. Porten, J. Schmid, E.H. Rühl |
| Keywords: | Leaf area, Phylloxera, sap flow, vitis vinifera, water consumption |
| Abstract:
Vineyards in Germany are mostly planted on Vitis berlandieri x Vitis riparia rootstocks. At these rootstocks Phylloxera can feed only on root tips causing root galls called nodosities. Any feeding on mature root, causing tuberosities, could not be observed. The effects of Phylloxera infection on water relationships of grapevine (Vitis vinifera) were investigated in a pot experiment at the Institut for Grapevine Breeding and Grafting, Geisenheim (Germany). The rootstock used was 5 C (Vitis berlandieri x Vitis riparia), the scions were White Riesling and Pinot gris (Ruländer). During the growing season 1998, the effect of root damage, caused by Phylloxera, on leaf area development and water consumption was studied on adequately watered plants, growing in 30 L pots. Water consumption of infested and non-infested vines was studied by sap flow measurement according to Granier.The Granier method allows a continuous measurement of the transpiration of the whole plant in the field. Transpiration was measured over a period of 66 days, starting on July 19, 1998 on three vines in each treatment. The mean cumulative sap flow of these three plants over the entire measurement period was expressed as sap flow per unit leaf area. The transpiration rate, expressed in litres per m2 leaf area, did not show any differences between infested and non infested vines. It can be concluded, that the presence of even high numbers of nodosities had no influence at the transpiration of the vine, if water supply was adequate. | |
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