202 CHAPTER XII 



In the Union of South Africa the buildings used for air- 

 curing are very simple in construction, but in other countries 

 where this method of curing is practised, the tobacco barns 

 are very costly and elaborate. Air-curing barns in South 

 Africa can be divided into three types, according to the 

 material used in their construction. The three types are 

 brick, corrugated iron, and grass. The results obtanied at 

 the Kustenburg Experiment Station of the Tobacco and 

 Cotton Division indicate that the best results are obtained 

 from the curing-sheds covered with thatch. Both grass and 

 corrugated iron may be used in the construction of sheds. 



Sun-Curing. — Turkish tobacco is sun-cured, and this 

 method is also employed in certain parts of America. Sun- 

 curing is similar to air-curing, in that no artificial heat is 

 employed to facilitate curing. The two methods differ in that 

 curing is hastened by exposing the leaf to the direct rays of 

 the sun in the one, whilst in the other the rate of curing is 

 largely regulated by atmospheric conditions. 



For sun-curing, the equipment required consists of a 

 wilting room and packing shed, scaffolds or trellises for ex- 

 posing the leaf to the sun, and a conditioning cellar for render- 

 ing the leaf pliable, so that it can be prepared for market. 



In sun-curing, the whole plant is usually harvested, but 

 the single-leaf method can be used when sun- and flue-curing 

 are combined. The usual method of sun-curing embraces the 

 following operations : The tobacco is harvested just before it 

 is fully ripe and placed on sticks in the Wilting room until the 

 leaf takes on a greenish-yellow colour. If no wilting room 

 is available the tobacco can be yellowed under grass, but 

 requires careful attention to avoid damage through the leaf 

 becoming too wami and turning black. When the leaf is 

 properly yellowed, it is removed to the scaffolds and exposed 

 to the sun until the whole leaf, including the midrib, is thor- 

 oughly dry. During this time some form of covering should 

 be provided to protect the tobacco from rain and from dew at 

 nights. For this purpose sail-cloth, hessian, or grass mats 

 can be used. The coverings are placed in position at night or 

 during showers, and are removed in the early morning, or 

 after showers have passed, to allow the tobacco to receive the 

 full rays of the sun. When the leaf is thoroughly dry the 

 tobacco is removed in the early morning to the conditioning 

 cellar, where it remains until the leaf is pliable, when the 

 tobacco is graded and either bulked or baled for marketing. 



