Relevance of model systems to field studies

The focus of the research just described utilizing the cucumber-nutrient culture and the cucumber-microbe-soil model systems was to identify and characterize what happens to phenolic acids once they enter the soil environment and how in turn this may influence the behavior and processes of phenolic acid-sensitive seedlings. The research was thus hypothetical, theoretical, and process oriented and not designed to answer speciflc questions related to actual field observations. When choosing any model system for study one hopes and assumes that the model system chosen is not unique but that the relationships and processes observed for the system chosen are representative of a broader array of other systems and hopefully relevant to field systems. 

How representative a model system is can be determined to some extent by testing other bioassay species and soils in the model system chosen and by comparing the biological and physicochemical characteristics and processes of model and field systems. The following considerations are thus worth noting  

2 Plant-Plant Allelopathic Interactions. Phase I The Laboratory 

Based on the observations for and limitations of our model systems, the following should be relevant for field systems. Only the timing and magnitude will vary. 

Finally, effects observed in soil model systems tend to more closely approximate what happens in nature (within limits of course, see above actually represent soil modified responses), while effects observed in nutrient culture tend to represent maximum potential effects of phenolic acids for a given environment and a given species. Both bioassay systems (nutrient culture and soil culture), therefore, supply useful information about the potential role and the mechanisms of action of phenolic acids but cannot provide information about what is actually happening under field conditions (Inderjit and Dakshini 1995 Romeo and Weidenhamer 1998 Inderjit and Weston 2000 Inderjit and Callaway 2003 Inderjit and Nilsen 2003 Blum 2007). 

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