MODEL PREDICTIONS OF OPTIMUM SHOOT DENSITY AND TRUSS SIZE IN GLASSHOUSE TOMATO

In the glasshouse cultivation of a long-season tomato crop, maximum fruit production is obtained when there is a proper balance between the demand and the supply of assimilate, and an optimum proportion of vegetative growth throughout the season in order to sustain the crop photosynthetic capacity.
These aspects of crop growth are mainly affected by fruit load which in practice is manipulated by shoot density and fruit thinning.

This paper demonstrates how a growth model, including routines for fruit development and dry matter distribution, can be applied to calculate the shoot density and numbers of fruit per truss that result in the highest fruit production.
The results indicated that maximum production is probably obtained at a fairly low leaf area index (2–3 m²m^-2) and associated light interception.
At supra-optimum leaf area index additional leaf area for extra light interception requires more assimilate than it would produce.
Further, the computations showed that in spring and early summer optimum shoot density is determined by the required number of fruits (i.e. sink capacity) whereas in summer a combination of high plant density and fruit thinning seems required for sufficient leaf area.

International Symposium on Greenhouse Crop Models

Ad N.M. de Koning

https://doi.org/10.17660/ActaHortic.1996.417.11