Politico.com has it:
The one eyebrow-raising moment came when Walker blanked on the name of Norman Borlaug. A procession of speakers had already heaped praise on the deceased Iowa biologist for unleashing the green revolution. Walker referenced him as the guy who had won the Nobel Prize, but he couldn’t remember who it was.Jason Noble at The Des Moines Register had it, too:
Not a good look from Walker, praising Borlaug, talking up event at World Food Prize, but unable to pick out his name.