THE PRODUCTION OF PLANTS 43 



difficult to control in the seed-bed, and where the 

 necessary facilities are available the seeds can be 

 destroyed by sterilization. On a small scale, as in 

 preparing the window tray, place the soil in a shal- 

 low pan and bake for two hours in an oven at about 

 the proper temperature for baking bread. On a 

 larger scale, soil sterilization can be accomplished 

 by discharging live steam from a boiler directly 

 into the soil. The usual method of steam steriliza- 

 tion is to first prepare and sift the soil, then shovel 

 it into a box, having a coil of perforated pipe in the 

 bottom. When the box has been filled and covered 

 the steam is turned on for several hours. The usual 

 test to determine when sterilization has been car- 

 ried far enough is to place a medium-sized Irish 

 potato in the soil near the central top part and apply 

 the steam until the potato is thoroughly cooked. 

 Practically the same results may be accomplished 

 by burning a quantity of brush upon the ground 

 intended for seed-bed purposes. Sterilization not 

 only destroys weed seeds present in the soil, but 

 insects and fungous diseases as well. 



Starting Plants in the Open Ground. — When it is 

 desired to secure plants in large numbers for plant- 

 ing the late or main crop, the seed is generally 

 sown in outside beds. The methods of prepar- 

 ing and handling these beds varies accord- 

 ing to the character of soil and climatic 

 conditions, but as a rule the land for seed- 

 beds is plowed in the autumn and fertilized 

 with about 15 tons of well-rotted stable manure, 

 which is free from weed seeds and i ton of bone 



