282 BREEDING CROP PLANTS 



WHAT IS GOOD SEED? 



There are certain characters of farm crops which must be 

 considered if the grower wishes to produce good seed. Good 

 seed of any farm crop must belong to a variety that is superior 

 in the following respects : 



1. Adaptability to the locality and soil. 



2. Yielding ability. 



3. Purity to type for small grains or self-pollinated crops, and comparative 

 purity for corn and other cross-pollinated crops. 



4. Quality for the particular characters for which the crop is grown. 



5. Hardiness. 



6. Erectness or ability to withstand lodging. 



7. Disease escaping or resistance to disease. 



The seed of the particular variety itself must be superior in 

 the following: 



1. Germinating ability. 



2. Good color, plumpness and weight. 



3. Uniformity. 



4. Freedom from diseases transmitted by seed. 



5. Freedom from any other damage. 



6. Freedom from obnoxious weeds. 



7. Freedom from mixture with other varieties. 



Adaptability. We have already indicated that no one variety 

 always excels in yield or quality. All that the experiment 

 stations can do is to determine the few better varieties and in this 

 way assist the farmer to decide which to grow. 



There are decided advantages in limiting the number of varie- 

 ties. It is of considerable value for one locality to produce large 

 quantities of a particular variety. Several reasons are apparent, 

 chief of which are: (1) The buyer can obtain a large amount of 

 seed of that particular variety. (2) The production of only a 

 few varieties or a single variety is of material help in keeping 

 purity of type, as there is not so much opportunity for (a) mix- 

 tures in thrashing, growing, etc., or (b) cross-fertilization between 

 varieties, which causes variability of seed and plant characters 

 and, therefore, loss of purity of type. 



Yielding Ability and Quality. Variety tests carried on under 

 experimentally controlled conditions are the best means of deter- 

 mining comparative yield and to some extent comparative quality 



