Production Practices and Quality Assessment of Food Crops. Vol. 1

Modelling Fruit Quality 63
Figure 6. Simulation with CaShoo of daily reserve kinetics in peach shoot bearing fruits for several
shoot-to-fruit ratios (S/F).
Table 1. Contribution (%) of different sources of variation of peach size at harvest in two simulated
experiments. One experiment concerned an early maturing peach cultivar (‘Alexandra’) and the other
a late maturing cultivar (‘Suncrest’). The factors under study were the initial size of leafy shoot, light
environment and initial size of fruit.
Suncrest Alexandra
Initial size of leafy shoot (LS) 32.2*** 30.6***
Light environment (LE) 21.8*** 14.6***
Initial fruit size (FS) 27.5*** 38.8***
Interaction LS:LE 12.0*** 00.9ns
Interaction LS:FS 04.1** 10.4***
Interaction LE:FS 01.7* 03.8**
Residuals 00.7 01.0
*** significant at p < 0.001; ** p < 0.01; * p < 0.05; ns: not significant.
5. THE QUALITY FROM THE AGRONOMIST’S POINT OF VIEW
For the agronomist, fruit quality can be defined by a set of fruit characteristics which
can be managed by technical operations. Choosing the technical operations, their
intensity and succession is a complex work to which agronomical models can contribute.
Two main types of decisions have to be taken to manage fruit production
in a plot. The aim of tactical decisions is to adapt the intensity of technical operations
to the state of the plant during the season of production. Indicators of the
plant vigour, water stress or sanitary state are often used as input in a model designed
to simulate the effects of technical operations on the plant. More strategic choices
have to be made before crop implantation or the season of production. In this case,
the decision concerns an adequate combination of operations in terms of type, intensity
and time of application. In the following section, a simple model useful in