Farmer Hugh Bowman hardly looks the part of a revolutionary who stands in the way of promising new biotech discoveries and threatens Monsanto’s pursuit of new products it says will “feed the world.” “Hell’s fire,” said the 75-year-old self-described “eccentric old bachelor,” who farms 300 acres of land passed down from his father. Bowman rested in a recliner, boots off, the tag that once held his Foster Grant reading glasses to a drugstore rack still attached, a Monsanto gimme cap perched ironically on his balding head. “I am less than a drop in the bucket.” Yet Bowman’s unorthodox soybean farming...