COTTON CULTURE 21 



phosphoric acid, and nitrogen they contain, and a short 

 account here of each may not be out of place. 



Potash. Potash is essential to the formation and 

 transference of starch in plants. Starch is first formed 

 in the leaves of plants, after which it becomes soluble 

 enough in the plant cells to pass through the cell walls 

 gradually and later to be carried into the fruit, where it 

 accumulates and changes back into insoluble forms, thus 

 contributing to the formation of pulpy matter in the case 

 of fruits and of lint in the case of cotton. Not only has 

 this function of potash been well established, but it has 

 also been proved that no other element or substance can 

 take the place of potash in performing this work. Potash 

 is also important on account of its influence upon the 

 development of the woody parts of stems, roots, bark, and 

 branches. 



Phosphoric Acid. Phosphoric acid is found in the 

 seeds of plants, and it has been discovered that plants 

 cannot come to maturity unless this element is present 

 in sufficient quantities. It hastens the maturity of plants 

 and tends to aid the plant in assimilating other fertilizer 

 ingredients. It also promotes the accumulation of al- 

 buminoids in the seeds. 



Nitrogen. The influence of nitrogen in its various 

 forms upon plant growth is shown by some very striking 

 effects. The growth of stems and leaves is greatly pro- 

 moted, while that of buds and flowers is retarded. Ordi- 

 narily, plants, after a certain period of growth, cease to 

 produce new branches and foliage, increasing those already 



