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

58 M. Génard and F. Lescourret
Figure 3. Seasonal variation in sugar contents and sweetness of peach flesh obtained with SUGAR.
The bold curves correspond to a 50% increase in carbon supply compared to the dotted curves.
These simulations explain in a comprehensive way the relationship previously
noted between flesh sugar contents at harvest and fruit growth (Génard et al., 1991
and 1999b). In accordance with the results presented in these papers, we found a
positive relationship between fruit growth and sucrose concentration in flesh at
harvest and no clear relationship for reducing sugars.
We computed the seasonal variation of sweetness due to each sugar (Figure 4).
The contribution of sorbitol was never significant and that of glucose was weak,
except early in the season. Before the hundredth day after bloom, fructose mainly
contributed to total sweetness. The importance of fructose was essentially due to