Stochastic Simulation of Fruit Set in Sweet Pepper

Fruit set in sweet pepper shows strong fluctuations in time, among others considered to be caused by imbalance between supply and demand for assimilates (called source and sink strength, respectively). Fruit set also varies between plants. This research aimed to improve simulation of fruit set in a process-based crop growth model by inserting a probability function for abortion. This probability is based on source and sink strength and introduces variation between plants. In a greenhouse experiment, flowering date and abortion (or harvest) of all fruits were recorded. Fruit set was analysed with a Generalised Linear Model, with source and sink strength as explanatory variables. The resulting function was inserted into a crop growth model. The model quite well simulated the timing in fruit set, although the amplitude was not always accurate. Simulating fruit set stochastically looks promising. However, more experiments are needed to make the function biologically sound.