Science: Chemical Frost

Growth-regulating chemicals are working an agricultural revolution. They defoliate cotton plants, enabling mechanical cotton pickers to gather clean cotton, something they could not do before. They make apples hang longer on trees. They kill weeds selectively. They semicastrate tomato flowers, and produce seedless tomatoes.

A new chemical just put on the market is an artificial frost for potatoes. When late potatoes reach maturity, farmers pray for frost to kill the vines. If it does not come, a lot of evils may. Potatoes grow lopsided, bumpy. Juicy vines clog the digging machinery, and blight...