Internodes are the spaces between the branches and the leaves, right? So some plants extend more toward the light, and you can correlate that with your models and determine if that's a good or bad thing?

Ort -- That's a good question: Is this extension a good or bad thing? I think that's a lot of what John's models tend to address. It's not always obvious if one particular parameter helps the crop's performance in the field. For example, early on in the season the ability to absorb light and cover ground with leaves is a good thing. But later on, is having lots of leaves down in the canopy that aren't getting much sunlight good or bad? Knowing whether or not it's a beneficial trait is extremely valuable before you get into the very expensive business of doing something about it, even from the standpoint of convention-breaking, much less from genetic engineering.