Source: Magness et al. 1971
The tobacco plant is a thick-stemmed annual bearing large leaves with short petioles or leaf stems. Leaf blades are often more than 20 inches long and half as wide. They rise in a spiral along the stem. Stems grow 4 to 6 feet tall and terminate in a cluster of flowers if not topped. Except for seed production, however, plant terminals are usually removed when flowering begins in order to increase size and thickness of leaves - the marketable portion.
Plants are usually started in beds under cloth cover in early spring and moved to the field after all hazard of frost is past. Growth in the field from setting to harvest covers 3 to 5 months. Harvesting may consist of removing most mature leaves by hand at about weekly intervals or cutting the whole stem. The former method is more generally used as it gives higher leaf yield and better quality. Leaves are then dried by one of several processes. In flue-cured tobacco, heat is applied in such a way that no smoke reaches the leaf hung in racks. In fire-curing, open fires are used and the smoke results in a darker colored, distinctlv flavored leaf. In air-cured tobacco no heat is added except as necessary to prevent mold during humid periods. Kinds of curing depends on type of tobacco grown and ultimate use.
Cigar wrapper tobacco, grown mainly in Connecticut, is produced under partial shade - resulting in thinner leaves and less damage to the leaves.
In the final products from tobacco (cigarettes, pipe tobacco, cigars, chewing tobacco, and snuff) the leaf midribs and larger veins are largely removed. They may be processed to obtain nicotine insecticides or used as mulching material. They are not used as feed.
Tobacco was grown on 967,000 acres in the United States - average acreage for 1966-67. Almost 66% of this was flue-cured and nearly 33% aircured. Less than 3 percent was fire cured. Around 50,000 acres was devoted to cigar tobacco.