The Cavendish banana is indeed a fine example of humanity cruisin' for a bruisin'. The Irish potatoes were a monoculture only in the sense that potatoes are potatoes. There are many varieties of spud, genetically diverse. Unfortunately, they are all, not quite equally but not that differently, vulnerable to blight. Which, Mr Red by the way, is a fungus, not a virus. And trees are plants and some plants are trees. The received wisdom is that blight caused the Irish Hunger. Never forget that there was ALWAYS enough food in Ireland to feed everybody, even to the point of obesity. The Hunger was the result of Irish people being priced out by the fact that the English were more than willing to pay a fortune more for food grown in Ireland than the Irish could afford to pay. We got fat while the Irish starved. Blaming the blight is to make the blight a scapegoat. The Hunger was caused by naked capitalism.