Re: Do C4 plants produce more glucose than C3 plants?

You will love this answer: it depends. This probably needs some explanation.

First, neither C₃ nor C₄ photosynthesis actually makes glucose; as the labels indicate, the molecules made are 3 and 4 carbon molecules, but these products can be changed into glucose for transport in phloem and for storage as starch (a glucose polymer).

Second, photosynthetic output is determined by an interaction between the physiological machinery of the plant and its environment. In hotter and drier conditions C₄ plants are more efficient, but in cooler and/or moister conditions where water loss through transpiration is not such a problem, C₃ can be more efficient. So you can define a set of conditions where C₄ plants will fix more carbon than C₃ plants, and vice versa.