You don't need patent enforcement for hybrid crops, which is pretty much every seed other than soybeans which is an heirloom crop. Corn has major hybrid vigor,

You don't need patent enforcement for hybrid crops, which is pretty much every seed other than soybeans which is an heirloom crop. Corn has major hybrid vigor, so only a totally ignorant farmer would try to replant harvested corn. Corn seeds are made by crossing two heirloom corn varieties at a seed farm, e.g. Southern Dent is crossed with Northern Flint (both are about 5 feet tall and make small ears), to make hybrid corn which grows about 8 feet tall and has massive ears. When you sell seeds, you don't get access to the heirloom plants needed to make the seed. No need for patents. With soybeans however, they breed true as heirlooms. The GMO beans were sold with the promise that farmers don't use the crop as seeds. Since everything other than soybeans are hybrids, the issue is largely moot.