Agree with Buck. Most regions typically have a sweet spot for which maturity range will do best on an average year. In my area, 2.8-3.2 would be considered the upper range of what typically yields best. We have a farm with 2.5 just to get started. Then in a perfect world the 2.7, then 2.8 and so on will fall in line and be ready each new day. If it stops raining in late summer, the early beans can yield better. If it doesn't rain all summer, then starts raining in August or early Sept, the long beans should do better. Guys in arid climates sometimes plant long season beans late, hoping to take advantage of that type weather scenario. Unrelated, but interesting, is that soybean breeders have been changing the leaf structure on newer beans. Nowadays the top of the plant in late summer will have thinner, smaller leaves to allow for more sunlight to reach down into the plant. Older varieties would look like a giant bush on top, and probably be taller (also breeding for shorter plants) and result in premature leaf senescence in the lower canopy during seed fill.
