Complex sentence: Gros Michel, or'Big Mike', was an early export cultivar of banana which was wiped out in the 1950s by Panama disease, a fungus which attacks the roots of the banana plant.
Split into simpler sentences: Gros Michel, or'Big Mike', was an early export cultivar of banana. In the 1950s is it was wiped out by Panama disease, a fungus which attacks the roots of the banana plant.