STEPS TOWARDS IMPROVING TODAY'S IRRIGATION PRACTICES IN PEACH

Sound application of efficient use of water involves accurate prediction of crop coefficients (Kc). In this research, we used CropSyst, a computer simulation model that can simulate the effect of the energy absorbed by the canopy and plant hydraulic conductance, to estimate irrigation requirements. Predictions with CropSyst were compared to best irrigation management practices. Among the growing conditions studied, we found that the use of different fruit loads and vigor-reducing rootstocks substantially changed irrigation requirements compared to standard conditions. An appropriate estimation of orchard daily light interception is the first step towards achieving more accurate irrigation scheduling. The rate of transpiration per unit of intercepted light was another parameter that varied with growing conditions (i.e., for different maturing times and fruit loads) and significantly contributed to the estimation of irrigation requirements. One implication of this study is that major inefficiencies may be found in current peach irrigation protocols. In the best case scenario, it has to be assumed that errors in scheduling irrigation can be higher than 20%. It is necessary to develop more sophisticated tools for determining irrigation requirements and thereby improve application efficiency.