Crops are cultivated at high density to achieve maximum yield. This causes the plants to grow together forming a canopy that becomes so dense light is unable to penetrate to the lower leaves. The upper canopy leaves receive more light than they are able to use for photosynthesis and the lower canopy leaves receive less light than they could use.
Computer simulations suggest that making the upper canopy leaves lighter and more erect, while making the lower leaves darker and more horizontal would allow higher levels of photosynthesis lower in the canopy, greatly increasing canopy photosynthesis and therefore yield. The simulations also suggest that crops produce too many leaves. RIPE is both engineering and selecting for these optimized canopy forms.
Obstacles to implementation: This is seen a medium risk since artificial manipulations to form optimal canopies have already resulted in increased yield.