328 



GRASS MIXTURES SEEDS AND SEEDING 



are unfavorable. No injury results from a very thick stand, while 

 it is not very practical to try to increase a stand that should prove 

 too thin. The quantity of seed used differs locally, but Piper gives 

 the following table as a general guide : 



The General Relations Between Number of Seeds Sown and Final Stand 



EXERCISES 



A STUDY OF THE GERMINATION OF SEEDS * 



(Prepared by A. T. Wiancko, Purdue University) 



Use seeds and boxes provided (see Chapter III). Place a piece of 

 blotting paper in the bottom of each tester or box and have a second piece to 

 cover the seeds. Saturate both pieces of blotting paper. Count 25 kernels 

 each of corn and wheat and place in one of the boxes. Count out the same 

 number each of clover and beans, and place in the second box. Cover these 

 seeds with the second piece of blotting paper. Put on the lid and set aside. 

 Examine every day to note progress of germination and condition of 

 moisture. 



1. What is the first act in the process of germination? 



2. Which appears first, the radicle (root) or the plumule (leaves) ? 



3. How many days are required for germination? 



4. Is there any difference in the manner in which the cotyledon (seed) 

 is disposed of after germination? Explain. 



5. Two modes of root development: axial, the radicle extending into a 

 taproot with more or less branches; diffuse, no evidence of taproot, but 



1 Reprinted from the author's " Examining and Grading Grains," pub- 

 lished by Ginn & Co. 



