MODELLING FRUIT SET IN GREENHOUSE VEGETABLE CROPS

A. Elings, P.H.B. de Visser
Greenhouse vegetable crops produce an abundance of flowers, that may or may not abort depending on the amount of allocated assimilates. Consequently, the abortion rate is determined by demand for and supply of assimilates. Assimilate demand of a fruit is a function of its temperature sum, whereas assimilate supply to a fruit is a function of the photosynthesis rate and competing sink strengths of other organs. This relation is modified by temperature. Because of the competition for assimilates, the presence of other fruits dominates the abortion rate of young fruits, resulting in the well-known flush patterns in fruit set and harvest. The Intkam crop growth model incorporates mechanistic descriptions of fruit set. The sweet pepper sub-model adequately simulated the majority of flushes in setting and harvest in terms of moment and magnitude, obtained from a grower in The Netherlands. The model was then used to analyze physiological sub-processes. Similarly, the less detailed eggplant model predictions were improved if fruit set and time to ripening were calibrated with registration data of the first weeks. Observed fluctuations in fruit set were less strong and showed no clear flush patterns compared to sweet pepper and cucumber. Consequently, fruit set for eggplant did not show a relationship with the computed sink/source balance of the crop. For a grower it is especially relevant to know the impact of a certain management action on the first flushes of setting and harvest, which enables better meeting market demands. A model that predicts such flushes can provide valuable information.
Elings, A. and de Visser, P.H.B. (2011). MODELLING FRUIT SET IN GREENHOUSE VEGETABLE CROPS. Acta Hortic. 893, 575-764
DOI: 10.17660/ActaHortic.2011.893.81
https://doi.org/10.17660/ActaHortic.2011.893.81
abortion, eggplant, fruit set, INTKAM crop growth simulation model, sweet pepper
English

Acta Horticulturae