Canopy interference of chickpea with sowthistle - model development

Descriptive and mechanistic models are powerful tools in biological studies. The main difficulty is mathematically expressing the responses to environmental conditions. Thus, the kind of questions that one needs to answer by developing a model should be explicit in their earliest stage. Having clear questions will help one to design a conceptual diagram to decide which elements of the real system should be taken into account and which elements should not. Weeds are one of the limitations to chickpea ('Cicer arietinum' L.) production, which is the fourth most important legume in Australian agriculture. The best method to control weeds in crops such as chickpea is through the use of integrated weed management (IWM). Appropriate IWM packages for chickpea should make use of the competitive ability of specific chickpea cultivars, herbicides, proper row spacings, seed densities and timing of crop planting. Having more competitive cultivars appears to be a viable approach for providing a safe and environmentally benign component for IWM. Common sowthistle ('Sonchus oleraceus' L.) is one of the world's most cosmopolitan weeds from the Asteraceae. It was chosen as the case study weed in this research.