The only thing i agree with you on is genetic engineering. And that is not startup space really. That is like giant bio-tech companies breeding corn seeds in a lab. You need a phD for that shit you dont just build a startup that 'disrupts' seed genetics.
Farmers know what is in their fields, but prices are affected by fields on other continents which the farmer doesn't know. Any information the farmer can get but you cannot is to his advantage. (this applies to all farmers, they need to know what happens in Ukraine, Brazil, Australia... But they need you to not know)
I know that there's been some success in remote sensing of aquaculture at the academic level that's also demonstrated some promise with drones.
VERY familiar, lol.
If the incumbents keep acting like the backside of a donkey, a new generation of repairable farm machines would probably work but need a lot of capital and damn good relationships with local dealers.