QualiTree is a generic fruit tree model that can simulate the effects of various cultivation practices on the development and within-tree variability of fruit quality. These practices include fruit thinning, summer and winter pruning, irrigation and tree training.
It considers a large range of fruit quality traits important for growers, retailers and consumers:
- fruit size,
- the proportion of total mass consisting of fruit flesh,
- flesh dry matter content,
- flesh concentrations of various sugars,
- and sweetness, a linear combination of sugar concentrations.
Combining both agronomic and physiology viewpoints, the model describes the tree as a set of objects—fruiting units organised into a tree architecture and viewed in detail, and other compartments viewed globally—that exchange carbon and are the targets of physiological functions that can be changed by cultivation practices. Though parsimonious in terms of 3D representation of the plant architecture, it is able to express a high degree of within-tree variability of fruit quality criteria.
QualiTree has been successfully tested using several datasets. A range of peach cultivars – from very-early to late- has been parameterised into QualiTree.
Simulation studies show the potential of QualiTree to predict how fruit quality profiles may change under various cultivation practices (pruning), abiotic stress (through irrigation management) and levels of biotic stress (foliar attacks by parasites). As expected, thinning intensity, water deficit and the damage caused by pests significantly affected fruit yield and quality traits at harvest. Simulation studies indicated that severe water stress during stage III of fruit development decreased fruit size whereas it dramatically enhanced sugar accumulation in the fruit flesh, especially in the case of glucose and fructose. Others simulation of foliar attacks by parasites showed that reductions in fruit quality were lower when attacks were late in the season.
Hence, QualiTree might be useful in the design of innovative horticultural practices combining regulated deficit irrigation strategies and plant-mediated control of pests.
F. Lescourret, N. Moitrier, P. Valsesia, et M. Génard (2010) QualiTree, a virtual fruit tree to study the management of fruit quality. I. Model development, Trees, vol. 25, no 3, p. 519–530.
J. M. Mirás-Avalos, G. Egea, E. Nicolás, M. Génard, G. Vercambre, N. Moitrier, P. Valsesia, M. M. González-Real, C. Bussi, et F. Lescourret (2011) QualiTree, a virtual fruit tree to study the management of fruit quality. II. Parameterisation for peach, analysis of growth-related processes and agronomic scenarios, Trees, vol. 25, no 5, p. 785–799.