76 LABORATORY MANUAL OF AGRICULTURE 



2. Corn plants two and four weeks old, seeded three inches 

 deep. 



Directions. Dig up a number of small corn plants for 

 this study. Be careful not to break the roots in removing 

 the plant from the soil. Remove the dirt which clings to 

 the roots, by washing. Make a study of plants seeded one 

 inch deep, one week old, two weeks old, three weeks old, 

 and four weeks old. Also plants seeded three inches deep 

 two weeks old and four weeks old. (In determining age 

 of plant count time from date of seeding.) 



Make drawings of the plants at different stages of growth 

 and at the different depths of seeding indicated. Show in 

 the first drawing the four temporary roots which develop 

 first, and in drawings of older plants the permanent root 

 system which develops later. Show how the distance be- 

 tween the temporary roots and the permanent root system 

 depends upon the depth of planting. 



The drawings should include the root system, stalk, and 

 leaves and their arrangement. 



