You can't get that knowledge to people just by diffusing improved seed. You have to improve knowledge together with seed. Field schools are the best way I know of to do that. There is also the issue of the durability of resistance. We can get resistant varieties to farmers, but that's not the end of the story.
Resistance has a long history of breaking down over time.
Farmers have to know how to react if a crop they thought was resistant suddenly begins to show signs of a disease attack, and they have to have alternatives for the next season. A good thing about the FFS approach is that farmers can decide what they want to know, and design experiments to provide answers. It's a liberating methodology in that sense. A. One thing they don't know is that late blight is caused by a microbe. If you don't know that there's a microbe involved, you can't understand how the disease progresses.