Matt has a great new post up on The Scientist Gardener called The Myth of Monocultures. He gives talks about the PBS special on Michael Pollen’s Botany of Desire (which I still need to watch myself), addresses some misconceptions about diversity and monoculture and talks about the best way to ensure crops aren’t wiped out by pathogens that can evolved to overcome a single resistance gene:
Theoretically, it would be useful to maintain crop populations with diverse resistance genes. The industrial application of this (multilines) invovles breeding many different versions of a favorite crop variety that are identical except for their resistance genes. As appealing as this idea is, it hasn’t really worked out in the real world. The alternate approach (pyramiding) seems to be more effective. Here, many different resistance genes are combined into a single crop variety. Pests and pathogens may be able to overcome a single gene at a time, but it’s usually almost impossible to simultaneously overcome several.
Think of it like the story of the three little pigs. [spoilers ahead ;)] (more…)