82 THE PLANTING OF SEEDS 



In commercial vegetable growing, seeds sown in drills out-of- 

 doors are almost invariably sown by means of a garden seed drill 

 (Fig, 44). This opens a furrow, drops, covers and firms the seed, 

 and marks the next row all at one passage of the implement across 

 the field. With a machine of this kind, one man can sow an acre a 

 day in drills twelve inches apart, if the seed bed has been carefully 

 prepared; but unless the soil is fine and the surface fairly even the 

 seed drill will not do satisfactory work. However, unless the seed 

 bed is in good enough condition for the seed drill to work properly, 

 it is not in good enough condition for the welfare of the seeds, 

 and more work should be put upon it before sowing is attempted. 



Most garden seed drills plant only one row at a time. However, 

 extensive growers of certain crops, such as onion sets, have rigged 

 up machines that plant as high as five rows at a time. Some of these 

 are operated by hand, others by a horse or a gasoline engine. When 

 peas are grown in large areas for canning they are usually sown 

 with a grain drill. Sweet corn and beans may be planted with 

 a regular corn planter, and sometimes even cucumbers and musk- 

 melons are planted on rich soil with this machine by using a 

 special plate. 



QUESTIONS 



1. What conditions are essential to the germination of seed? 



2. How may a supply of moisture be maintained in direct contact with the seed? 



3. Why will seeds not germinate properly in a poorly drained soil? 



4. At what temperatures do seeds germinate? 



5. How may the proper temperature for germination be secured? 



6. What factors determine the depth for planting seeds? 



7. WTiat two factors determine the distance for planting seeds? 



8. Mention the proper distances for a number of common vegetables. 



9. TMiat advantages are claimed for thick seeding of vegetables sown in driUs? 



10. WTiat difficulties arise as a result of thick seeding? 



11. What is the present tendency among commercial vegetable growers in 



regard to thickness of seeding? 



12. If thinning of the seedlings is necessary, when should it be done? 



13. WTiat are the two general methods of sowing vegetable seeds? 



14. Describe the four distinct operations involved in the sowing of seeds by hand. 



15. What advantages has sowing with a garden seed drill over the hand 



method of sowing seeds? 



16. With what crops is thinning practiced in your locality? 



