Reminds me Paolo Bacigalupi's stories, "Wind-up girl", "The calorie men" and others. He's created a dystopian world of GM crops being the only viable food source on the planet.
https://en.wikipedia.org/wiki/Plant_Patent_Act_of_1930
Like all patents, there are limitations, expiry dates, etc.
It's been around for nearly a century, yet we haven't arrived at the dystopian future yet.
If people were willing to eat primarily vegetarian, we'd be perfectly able to feed everyone with regular crops. The article even said as much...China's inability to feed its population stems from their love of meat.
They already are.
Or do you think maize and the current varieties of wheat, fruit trees, rice, and so on are natural?
Plant patents last for 20 to 30 years and are quite robust. The main exemptions are for seed saving (irrelevant for hybrid crops), use as a progenitor (irrelevant to transgenics which vary at a single locus), and for compulsory licensing.
With the exception of the latter issue, these aspects have no bearing on GM. Seed saving would be an issue in crops that typically are not grown as hybrids. However, utility patents are shorter in duration and require disclosure. There's nothing stopping someone else from going out to find germplasm with a similar trait and generating their own construct. With advances in technology, this becomes ever easier to do. The supreme court's ruling on the BRCA genes makes it quite clear that this is permissible and would not be restricted by a utility patent.
In my estimation, a utility patent is less restrictive.
What's more, there's also quite a nasty patent thicket covering the techniques used in creating GM crops, so you can't just dodge the problem by going out and creating your own GM plant. It's one of the reasons golden rice was doomed to fail - it requires patent licenses from something like 30 companies because of the techniques it uses, including all the big biotech corps. Its creator managed to get heavily restricted free licenses for them because it made a good PR weapon against anti-GMO activists (his explanation), but the conditions make it pretty much useless. Only subsistence farmers or countries which can't grow enough calories to feed their population are legally allowed to grow it, and out of the latter I think only the Philippines even has the right climate to grow rice.