In the summer of 1846 Henry Thoreau planted and tended a 2 ½ acre plot of beans near his cabin at Walden Pond. Like many portions of Walden his description of farming which he entitled “The Bean Field,” is a trope. He offers a precise account of purchasing a hoe for 52 cents and harvesting 12 bushels 8 quarts of beans (apparently a small round white variety) after a summer of labor against weed and woodchuck. But his principal crop was a deep contemplation of himself, the value of self-reliance and the appropriate relationship between man the environment. Having grown a few beans myself I’m not surprised that beans were the agricultural foil for Thoreau’s farming venture. It’s hard to really look at a bean patch and not get worked up thinking about one thing and another.
This year I’ve planted sixteen varieties of beans but none in a row longer than twenty feet. You don’t need a bushel basket of beans to harvest a bumper crop of thoughts. For example, I’ve been watching my row of ‘Golden of Bacau’ beans (picture below) and comparing them with a more modern French haricot vert bean “Boby Bianco” growing a few feet away.
The Golden of Bacau bean is an heirloom from Romania which was introduced into the United States in 2004 by Seed Savers. It has a “pole habit” which means that it must be grown against a trellis to accommodate its six or seven foot height. The Boby Bianco bean is a modern bean and is the current favorite in Parisian markets. It has a “bush habit” which means that it grows to about 20 inches in height and can stand on its own. More or less.
The bush bean habit is the result of modern human selection. Wild beans don’t look much like any domesticated bean. All wild beans grow as long vines which readily climb shrubs and trees. The vining trait is controlled by a single gene called “Finalis” or “Fin.” It turns out that a common mutation in the Fin gene can dwarf a bean although two copies of that gene, “fin”, must be present. Plant breeders have been successful in creating bush or dwarf varieties by repeated selections of beans carrying the fin mutation in its chromosomes.
The story of bush beans and the Fin gene has become substantially more complex in recent years as portions of the bean genome have been decoded. We now know that the Fin gene is located very close to a number of other functional genes. When genes are closely spaced they often influence one another or ‘travel’ together as package causing multiple changes although only one or two may be visible. The close spacing of these bean genes was a bit unexpected since the entire bean genome is quite large and could allow for a more generous spacing. But this may explain why dwarf or bush beans usually have other changes in their branching and foliage cover pattern.
The bean genome findings have also refueled a long-simmering debate amongst bean farmers and bean lovers: taste. Many people insist that bush beans don’t taste as “beany” as do the “old time” pole beans. Plant breeders have poo-pooed this claim by pointing out that bean taste is in the pod and not in the stalks but now the bean genome should have them sweating a bit. Its now clear that a bush bean is likely to differ from its tall parent in more ways than one.
Personally I think it revealing to study the bean genome at ground level aided by a nearby pot of boiling water. I pick a few Golden Bacau beans (Fin) while standing up and then snag a handful of bush-y Boby Bianco beans (fin) while kneeling. Add both to a large cooking vessel for a controlled experiment. The results aren’t likely be published but they are highly digestible and that’s a form of science I can live with.