MODELING OF CUCUMBER GROWTH USING THE L-SYSTEM

When fruit vegetables such as cucumbers cucumis sativus L. are raised, crop architecture must be controlled by cutting, suspending and pinching down. These plant form management techniques relate closely to growing period, harvesting period, yield, labor efficiency, etc. The L-systems are a suitable method for representing the growth and generation of organisms, and it is possible to express plant morphologies using rules of replacing characters. We modeled cucumber growth, including a plant architecture, using the L-systems.

In this model, an initial description is made by symbolizing the parts of a plant body, such as a leaf, an internode and a female flower. The symbol characters are successively replaced using the rules of production, which are chosen by probability (the stochastic L-systems). To determine the empirical values of the stochastic parameters for the model, several different cultivars were grown hydroponically. The various cultivars showed differences in branching and bearing patterns; for example, some cultivars bore female flowers at almost every node. These differences in pattern were represented by the values of the stochastic parameters.

The influence of topping on branching and the growth of lateral branches was investigated. Typically, when plants were topped at low node order, branching and branch growth increased more than that of plants topped at high node order. These influences were also represented in the stochastic parameters.

Modeling plant architecture with L-systems might help choosing e.g. appropriate cultivars and crop management techniques.