Influence of greenhouse versus field testing and taxonomic differences on plant sensitivity to chemical treatment

Data present in the PHYTOTOX data base were analyzed to determine the influence of greenhouse vs. field conditions, and of taxonomic differences on the response of terrestrial plants to a wide range of herbicides. In the greenhouse vs. field analysis, consideration was given to the response of 13 plant species to 1 or more of 17 chemicals. The influence of taxonomic differences was examined by comparing the response of 151 plant species (43 families) to 1 or more of 16 chemicals representing 11 different classes of herbicides. Analysis of this large body of comparative data drawn from approximately 230 published papers would not have been feasible without the use of computerized data assembled in PHYTOTOX. These analyses showed that the magnitude of variability between laboratory and field data was 1.8 with a confidence interval of ±0.4. In comparison to this a similar analysis of data pertaining to a broad spectrum of taxonomically different plants showed that the mean sensitivity ratio was 10.5 with a confidence interval of 3.5. Thus, this study indicates that taxonomic differences among plants have a much greater influence on plant response to chemical treatment than does testing condition (greenhouse vs. field).