190 CHAPTER XII 



The above tabulation is not given for comparative pur- 

 poses between the air and sun curing methods, as obviously 

 all Turkish tobacco is manufactured into cigarettes, but to give 

 an approximate idea of the percentage of cigarette leaf pro- 

 duced in the Union. 



Description and Classification. — Tobacco belongs to the 

 genus Nicotiana, which includes about fifty species, mostly 

 of the American tropics. A number of species are gro^^n for 

 ornamental purposes. 



Two species, both summer annuals, are grown commer- 

 cially in the Union, (a) N. tabacmu (Virginian tobacco) has 

 sessile decurrent leaves; pink, yellow, purple or white flowers, 

 (b) N. rustica (Pondo tobacco) has petioled leaves, leathery in 

 texture, somewhat cabbage-like in appearance, and flowers of 

 a pale greenish colour. Turkish tobacco, while very unlike 

 Pondo tobacco, is held by some to be a strain of rustica. 



That the tobacco plant is, in all probability, naturally 

 close-fertilised, is borne out by the fact that self -fertilisation 

 (inbreeding) under control does not result in a loss of vigour. 

 Cross-fertilisation is probably somewhat frequent. 



Seedlings and Seed- Selection. 



The methods of culture, curing, and treatment, differ for 

 each type of tobacco grown in South Africa. However, the 

 principles underlying the production of seedlings, and seed- 

 selection, are common to all. 



Seed Beds. — These should be well prepared, more thor- 

 oughly than for the other common field crons, and the soil 

 should be in a state of high productivity. Unlike Northern 

 countries, where hot-houses or glass frames are generally neces- 

 sary, in South Africa the open frame is practically the only 

 type employed. 



As the beds are sown in the late winter or early spring, 

 they should be placed in a warm situation, protected from cold 

 winds, and where they can receive the maximum amount of 

 sunlight, especially early morning sun. Wind-breaks of maize 

 stalks or reeds should be provided if there is no natural wind- 

 break. The site as well as the beds should be level, otherwise 

 when watering the small seed is liable to be washed to the low 

 parts of the beds. 



Soil. — This should be deep, well drained, friable — pre- 

 ferably a light, sandy loam. If no suitable soil is available, 

 and as the beds are comparatively small, wagon loads of sand, 



