| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Brassica oleracea var. gemmifera | Seed | -- | -- | * | |
| Brassica oleracea var. italica | Seed | -- | -- | Jim Duke's personal files. | |
| Brassica oleracea var. botrytis l. | Seed | -- | -- | * | |
| Brassica oleracea var. capitata l. | Seed | -- | -- | Jim Duke's personal files. |