466 



TOBACCO PRODUCTION 



using a furnace or steam. The furnace used is on wheels and is 

 placed on the bed. It is about 9 by 3 feet and has a pan that will 

 hold dirt off that much space of ground to a depth of about two 

 inches. Dirt is baked in it for an hour and then is returned where 

 it came from. More dirt is taken up on the other side of the 

 furnace. After this has baked an hour the machine is wheeled on, 

 as the dirt underneath will have been sufficiently heated. In treat- 

 ing with steam an engine and a metal box are necessary (Fig. 197). 

 Steam is forced in the box that is turned upside down on the bed 



FIG. 197. Sterilizing tobacco beds by steam. (Pennsylvania Bulletin 130.) 



until the soil is heated to a temperature of 175 F. to a depth of four 

 inches. This temperature should be maintained an hour. This 

 form of treating tobacco beds has been most satisfactory. Sometimes 

 logs are laid around the plant bed, which is usually six or eight feet 

 wide, and in other cases boards are set up. A ditch should be opened 

 around it and one should lead from this to afford good drainage. 

 Cross-drains are sometimes needed. After burning, the soil is 

 worked up with a plow or hand tools. 



Sowing the Seed. The rate of seeding varies greatly with the 

 section. In some cases a teaspoonful of seed is sown to 100 square 



