Here's why:
* Regional variations: The word "corn" can mean different things depending on where you are. In the US, "corn" typically refers to maize. In the UK, "corn" often refers to wheat or other grains.
* Lack of common usage: There isn't a commonly used diminutive like you might find for other words (e.g., "little" for "small").
You could try these options:
* Informal: "Little corn" or "tiny corn"
* Descriptive: "Corn kernels" or "corn niblets"
Ultimately, the best way to express a diminutive of "corn" depends on the context and your desired level of formality.