Today would have been the 96th birthday of Frits Went, a Dutch-born American botanist who discovered the role of the plant hormone auxin and paved the way for the development of weed killers, fertilizers, and genetically engineered crops.
While studying oat seedlings, Went found that auxin produced at the tip was distributed preferentially down the dark side of the shoot, which explained why seedlings grow faster on that side and bend toward the light. In 1927, his theory of phototropism was not well accepted, but eventually it shaped the new field of agricultural chemistry.
Went also developed the first phytotron--a greenhouse that mimics natural climatic conditions--which was built in 1949 at the California Institute of Technology in Pasadena. And on a trip to Brazil in the late 1960s, Went discovered that Amazon forest soil was riddled with a network of fungi, which he proposed digest the tree litter and pass nutrients to intertwined tree roots. That theory was used to bolster the growing movement to save the rainforest from clear-cutting.
[Source: Emily McMurray, Ed., Notable Twentieth Century Scientists (Gale Research Inc., ITP, 1995).]