Simulation of stem diameter maximum daily shrinkage for peach under full irrigation

Field experiment was conducted by measuring the maximum daily shrinkage (MDS) and analyzing the relationships between MDS and reference evapotranspiration (ET0), net radiatio (Rs), daily mean vapor press deficit (VPDm), vapor press deficit at midday (VPDmd), daily mean temperature (Tm) and temperature at midday (Tmd) for 6-year-old "Shinvhong" peach under well irrigation, then MDS simulation equation was established to provide technology for precise irrigation scheduling. The results showed that MDS changed similarly with meteorological factors during the experiment periods; however, meteorological factors had different effects on MDS. By path analysis, the direct and total impacts and the decision correlation of Rs and Tmd were the best, and ET0, VPDm, VPDmd, Tm, showed indirect impacts on MDS by Rs and Tmd. So, Rs and Tmd were the main factors that showed impacts on MDS. Based on this, MDS simulation equation was established. There were no significant differences between calculated MDS using the simulation equation and measured MDS. Therefore, the values of MDS calculated from the equation can be used as reference ones, and the standard values of MDS can provide technical support for precision irrigation of peach.