It is not statistically valid to compare results between trials even if co-located. This is because different trials at a location are:

• Spatially separated creating increased site variability,
• Managed differently according to the herbicide system, maturity group, and species, e.g., canola herbicide tolerance trials, bread wheat vs durum wheat trials, barley vs wheat,
• Statistically managed as separate experiments, including in their design and analysis.