Quality seeds/plant prototype with quality dependent yield

[radical_larry]

This general topic has probably been discussed a lot by now as far as game balancing goes, but this request is purely about the modding API.
Seeds would get a property to allow that seed to place quality plants. Quality plants would get two new properties, whether to yield their product in their respective quality, and by how much the yield of the plant should increase/decrease with higher quality.

This would allow for all sorts of combinations, from quality seeds giving a bigger harvest per plant, to higher quality products from plants with less yield, and whatever else people can come up with.