Articles
MODELING YOUNG PEACH TREE EVAPOTRANSPIRATION
Article number
584_12
Pages
107 – 113
Language
English
Abstract
A model of young peach tree evapotranspiration (ET) was developed using data from a large weighing lysimeter.
Two Crimson Lady peach trees were planted in the lysimeter in January 1999. Data from the 1999 season were used to create the model and from the 2000 season to validate it.
There are 2 components to the model.
First, tree transpiration was modeled as a function of reference ET (ETo) and canopy size, as measured by canopy light interception at solar noon.
Estimates of tree transpiration were obtained from lysimeter values on the day before weekly basin irrigation when the soil surface was dry.
The equation derived for this relationship agreed very well with values obtained previously with mature trees when the lysimeter surface was covered with a tarp (Johnson et al., 2000). Second, soil evaporation was modeled as a function of ETo, days after irrigation, dimensions of the wetted area, and percent of the wetted area receiving full sun over the course of the day.
Overall, the model generally fit the 1999 data from the lysimeter, although it tended to underestimate the peaks associated with irrigation events.
It successfully predicted ET during 2000, except for the very end of the season when subsurface irrigation was used.
Some additional research may be needed to explain these aberrations, but in general the model was quite accurate in predicting young peach tree water use.
Two Crimson Lady peach trees were planted in the lysimeter in January 1999. Data from the 1999 season were used to create the model and from the 2000 season to validate it.
There are 2 components to the model.
First, tree transpiration was modeled as a function of reference ET (ETo) and canopy size, as measured by canopy light interception at solar noon.
Estimates of tree transpiration were obtained from lysimeter values on the day before weekly basin irrigation when the soil surface was dry.
The equation derived for this relationship agreed very well with values obtained previously with mature trees when the lysimeter surface was covered with a tarp (Johnson et al., 2000). Second, soil evaporation was modeled as a function of ETo, days after irrigation, dimensions of the wetted area, and percent of the wetted area receiving full sun over the course of the day.
Overall, the model generally fit the 1999 data from the lysimeter, although it tended to underestimate the peaks associated with irrigation events.
It successfully predicted ET during 2000, except for the very end of the season when subsurface irrigation was used.
Some additional research may be needed to explain these aberrations, but in general the model was quite accurate in predicting young peach tree water use.
Publication
Authors
R. Scott Johnson, J. Ayars, T. Hsiao
Keywords
Prunus persica, water use, lysimeter, irrigation, canopy light interception, ET, soil evaporation
Online Articles (32)