Check out this recent report published by IFPRI on Ag Development: Millions Fed: Proven Successes in Agricultural Development. The timing could be better. Just a couple weeks ago FAO announced that food production will have to increase 70% by 2050.
The report identifies about 20 successes across the developing world, spanning from interventions enhancing productivity to combating diseases and pests, conserving natural resources, expanding market opportunities, improving human nutrition, and improving the policy environment. A common thread running through many of these successes is the confluence of science, policy, and leadership. Hope those making key decisions get to read it.