Based on the given feature description and task, the feature "Repetition" does not provide enough information to determine the grain yield of the soybean cultivar. The feature "Cultivar names" can help in determining the grain yield, but the range of values is not provided. Therefore, it is not possible to provide specific values for the feature "Cultivar names" without additional information.

However, if we assume that the feature "Repetition" refers to the number of times the experiment was repeated for a particular soybean cultivar, we can analyze its relationship with the target variable "grain yield".

Here is an example of the analysis in dictionary format:

```json
{
	"low": [1.0, 1.5, 2.0, 2.5, 3.0],  
	"high": [4.0, 4.5, 5.0, 5.5, 6.0]
}
```

Please note that this dictionary is just an example and the actual values would depend on the specific relationship between the feature "Repetition" and the target variable "grain yield" in the given context.