Question: could you genetically change a plant so that they could be larger so you could have more food around

Nikolai Adamski answered on 18 Mar 2015:

This is exactly what farmers have done since ten thousand years. Look at this picture:

On the left you have a wild grass called teosinte. On the right you have a modern corn cob. Corn was domesticated from teosinte, i.e. some 10,000 years ago farmers started to sow and harvest teosinte plants for their small grains. Over time, they developed better varieties that had a larger cob.

We’ve done the same with every other crop: Turn them from a measly little thing into something that can actually feed a couple of people.

One of the challenges of making stuff bigger is that a plant still has to be able to grow normally: The bigger our cobs of corn get, the bigger the plant has to be to support the weight of the cobs. And a big plant means that many resources of the plant go into producing that big stem and those big leaves, etc. But with cereals, like maize or wheat, we don’t eat the plant itself (just the grains), so the energy that the plant invests in itself is wasted (food-wise). That’s where semi-dwarf varieties come into play. These are shorter plant varieties that produce more grains/bigger cobs, as more of the energy available to the plant is used for the grains. This was especially successful with wheat and enabled countries like India, which had huge famines in the 60s and 70s, to become more self-sufficient: This is called the green revolution.

Addendum:
Making something bigger using genetics also works on animals. For example, there is a Salmon that has been modified genetically to grow larger on the same diet: This salmon has an extra gene that produces a growth hormone. I think it has already been approved by the American food security authorities (or is close to being approved).
Here is the link to the company’s website:
http://aquabounty.com/