DISSEMINATION OF GRAINS 119 



Dissemination of Improved Grains. After a grain is 

 improved it is important to have the seed as widely dis- 

 seminated as possible so as to test its value under varying 

 conditions of soil and climate. 



The aim of the grower of pedigree seeds is to get the 

 entire community in which he resides interested in growing 

 these grains instead of the common varieties. When their 

 merits are known pedigree grains soon displace the numer- 

 ous common varieties. 



EXERCISES 



1. Why must the crossing of pollen in small grains be done 

 by hand ? 



2. How does this process differ from crossing in corn? 



3. Why do crossed varieties tend to break up into several 

 varieties ? 



4. How does the grain breeder prevent this breaking up of 

 strains ? 



5. Which are most likely to come true to type, crossed or 

 selected varieties? Why? 



HOME PROJECT 



On the home farm carry on a plot for the improvement of 

 some grain or other useful plant, following directions given in 

 this chapter. 



