Yes! That is indeed an area of research currently…. There are past and current examples of how this type of research has been successful, in particular on that example you mention: making crops (or certain types of plants) grow faster and more abundant, so that you can produce as much of a crop using less land or/and less water/pesticides/herbicides.
Another example (very cool, in my opinion) is using genetic modification to alter the parts plants are made of. Normally plants contain three main components: cellulose (sugars called glucose), hemicellulose (sugars of other types), and lignin (which is not sugar-like, on the contrary, it’s other type of chemical component that has “aromatic” molecules). For producing ethanol fuel from plants, we want plants that have more cellulose/hemicellulose than lignin… because lignin cannot be converted into ethanol unfortunately, and lignin also make plants more difficult to react towards forming ethanol. So, some people has worked on precisely that: modifying the genetic configuration of plants so they have less lignin, or a lignin that will not interfere in such a negative way with the production of biofuels… How cool is that?!
In any case, I would like to tell you that lignin is not completely a bad guy… They are just made different and need to follow specific types of reactions so that they can be used as biofuels or energy… but still, if we want to produce liquid fuels like ethanol, the genetic modification may help so much to make the technologies more economic and so easy for companies to use everywhere!