150 AGRICULTURAL BOTANY 



fruit or seed depends wholly upon the number of 

 flowers developed. This subject is not well understood 

 by the botanist, but this general principle seems to be 

 fairly well established : Whatever tends to favor the 

 accumulation of surplus food promotes flower -bud forma- 

 tion. This means sufficient air and sunlight and pro- 

 tection of the foliage, sufficient plant food and moisture 

 in the soil, and a moderate check to growth after a 

 proper growth has been attained. 



Methods of Plant Propagation. Plant propaga- 

 tion is the multiplication of plants by natural or arti- 

 ficial means. Flowering plants are reproduced both 

 naturally and artificially by seeds, rootstocks, stolons, 

 suckers, bulbs, corms, and tubers. Flowerless plants 

 are reproduced by spores, a peculiar cell structure with 

 no embryo; but as only the lower orders of plants are 

 thus propagated, the consideration of this method 

 will be left until plant diseases are studied. 



Seed Propagation. We have learned that a seed 

 is a plant in embryo with a supply of food formed by 

 the parent plant either in the embryo or surrounding 

 it. The whole is inclosed in seed coats.. 



As the farmer's crops depend so largely upon the 

 germinating and growing power of the seed used, knowl- 

 edge of how to select seed is of the greatest importance 

 to him. There are many reasons why seeds do not 

 germinate even when given the proper amount of heat, 

 water, and oxygen. They may have been kept too 

 long, they may have been stored where it was either 

 too dry or too damp, they may have been gathered 

 before complete maturity, they may have been frozen 

 or chilled before being dried, or they may have been 

 injured by insects or fungus growths. No one of these 



