INFLUENCE OF TWO DIFFERENT TRAINING SYSTEMS ON W.U.E OF GRAPEVINES

The influence of two training systems - head training and cordon training - on Water Use Efficiency (W.U.E) was examined in field grown grape vines (Vitis vinifera L.) in order to evaluate the optimisation of the production under drought conditions. Cordon trained vines exhibited higher diurnal photosynthetic and transpiration rates presumably due to better utilisation of photosynthetic active radiation. Higher transpiration rates resulted in lower diurnal values of leaf water potential in cordon trained vines. The relationship between W.U.E and leaf water potential showed that W.U.E in cordon trained vines was higher for leaf water potential values greater than -0.9 MPa. At lower values of leaf water potential there was no significant difference in W.U.E between the two training systems.