In cucumber (Cucumis sativus), imbalances in growth between individual fruits can be related to the partitioning of assimilates. Using L-Studio software, Wiechers et al. develop a model combining architectural development, photosynthetic biochemistry and assimilate partitioning, with the latter including fruit growth. They find that simple partitioning models fail to simulate individual fruit growth realistically, but the introduction of thresholds for abortion and dominance related to source and sink strength, respectively, give results that are in line with measurements. Thus these factors need to be considered when simulating typical fruit growth traits.