A CHEMICAL STUDY OF THE ASPARAGUS PLANT. 295 



Summary. 



During the earlier years of the asparagus field the crowns and roots 

 steadily increased in size, doubling in weight between the second and 

 fourth years after setting. The proportion of protein remained nearly 

 constant in the dry matter of the roots during the period observed, while 

 the sugar decreased and the cellulose and allied compounds increased. 



The composition of the young stalks cut in the spring changed as the 

 cutting season advanced. Dry matter was practically constant, but sugar 

 increased in proportion while protein decreased somewhat. 



The development of the asparagus tops to maturity was accompanied 

 by a continuous increase in the cellulose and its related groups, — pento- 

 sans and lignin. Protein and sugar decreased in their proportions, but 

 were not wholly translocated to the roots from the ripened tops. 



Water was the dominant constituent of the asparagus plant in all the 

 stages studied. It was highest in the young stalks. The summer or grow- 

 ing roots were a little more watery than the late fall or storage roots. 



Calcium oxide and sulfuric acid steadily accumulated in the asparagus 

 tops as they grew old, but potash and phosphoric acid were transferred 

 either to the fruit or back to the roots. 



Withholding one of the constituents of a complete fertilizer from the 

 annual top-dressing was accompanied by a smaller average weight of 

 roots in the samples taken from the plot thus treated. Withholding ni- 

 trate of soda lessened the percentage of nitrogen and of soda in the roots; 

 withholding muriate of potash lessened the proportion of potash in the 

 roots; withholding acid phosphate produced no apparent change in the 

 constituents of the roots. 



An increase of nitrate of soda from the minimum to the medium amount 

 in the top-dressing caused an increase in the percentage of nitrogen in the 

 dry matter of the roots. 



An increase in the amount of muriate of potash produced some increase 

 in the percentage of potash in the roots. 



Asparagus roots taken from plots receiving the nitrate of soda in the 

 spring were noticeably heavier in weight and a little poorer in nitrogen 

 than roots from plots that were top-dressed with nitrate in the summer. 



During the cutting season the production of young stalks drew most 

 heavily on the sugar contained in the roots, but there was no approach to 

 exhaustion of that constituent. Fully twice as much sugar was consumed 

 as would have been required to produce the carbonaceous matter in the 

 young stalks. 



The roots apparently absorbed nitrogen, lime and suKuric acid during 

 the cutting season. Potash and phosphoric acid were apparently supplied 

 to the young stalks wholly from the reserves in the roots. 



