CHAPTER VII 



POOR SEED 



It has been briefly stated, page 88, that 

 seeds can be carriers of various diseases. The 

 trucker may also experience difficulty in the germi- 

 nation of seeds which may be accounted for in many 

 ways. 



Age of Seed. In determining the causes of poor 

 germination the age of the seed is to be considered, for 

 after a certain age limit deterioration sets in. With 

 many species of seeds there are apparently no ex- 

 ternal symptoms to indicate loss of vitality due 

 to age. Each seed has its own age limit, generally 

 determined by the character of the seed itself, i. e., 

 whether oily or starchy or lacking in both. Thus the 

 vitality of the minute seed of tobacco is perhaps eight 

 times as great as that of the large oily seed of the 

 castor bean. 



Cultural Conditions. The viability of seed is also 

 largely determined^ by the conditions under which 

 the previous crop grew. The more vigorous the 

 mother plant the more vitality will there be im- 

 parted to its offspring. The vigor of the previous 



crop depends on favorable climatic conditions, 



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