Tobacco, Nicotiana tabacum (family Solanaceae), is grown in over one hundred countries around the world, in both temperate and tropical climates. It is a stout, rapidly growing annual, 1 to 2 meters tall. It has large, ovate to oblong leaves and produces numerous white-pinkish flowers with corollas about 2 centimeters long. Tobacco seeds are minute, so in commercial production seedlings are generally produced in plant beds or in greenhouses and transferred to the field. Production and harvesting methods differ widely depending on the type of tobacco being produced, but most tobacco types require significant inputs of time, labor, and pest management. Both underfertilization and overfertilization may cause inferior quality leaves. Commonly, whole plants of air-cured tobaccos are cut off just above the ground and hung in barns for several months until cured. Leaves of bright, flue-cured tobaccos are typically harvested individually as they ripen. These leaves are cured by heating them...