Dicamba damages a soybean plant in a distinctive way, making it relatively easy for farmers and researchers to track the trouble. Normally, a soybean leaf curves slightly outward and downward; if rain were to fall, it would slide off of the bean’s leaf. But a soybean exposed to dicamba takes on a cupped appearance, with the leaves moving upward with slightly fringed edges. That's because dicamba kills by mimicking plant hormones called auxins, which are responsible for growth and development. Imagine a lock and a key: the plant holds receptors—the lock—awaiting a hormone, a key, to tell it how to behave. Dicamba slips into the lock, altering plant development in ways that can kill. But depending on when it hits a soybean, it might simply stunt the crop's lowering yield. Either way, it costs that farmer money.