296 MASS. EXPERIMENT STATION BULLETIN 171. 



Practical Conclusions from the Chemical Study of the Asparagus 



Plant. 



Asparagus roots that had been set in the spring of 1907 were found to 

 have doubled in size and weight between November, 1908, and November, 

 1910. During this period of rapid growth the percentages of the different 

 fertiUzing constituents in the dry matter remained constant or else in- 

 creased slightly. 



Absence of nitrogen, phosphoric acid or potash from the annual top- 

 dressing was found to limit the growth of the roots. 



Withholding nitrate of soda from the top-dressing, or applying it in 

 relatively small amounts, resulted in lessening the percentages of nitrogen 

 in all parts of the plant. 



A complete fertilizer rich in nitrogen is clearly shown to be required in 

 generous amounts in order to produce a continuous strong development 

 of the asparagus plant. 



Water is of prime importance in all parts of the asparagus plant at all 

 stages of growth. It is especially important in the spring months during 

 the cutting season, since the young stalks contain about 92 per cent, of 

 water, while the roots at this period are more watery than in the faU. 

 The physiological need of water, together with the sandy quality of most 

 asparagus soils, indicates that irrigation would be advantageous if not 

 necessary in the production of maximum crops. 



The reserve material stored in autumn in the roots was found to be 

 principally sugars. Sugars were also prominent in the spring stalks and 

 both summer and fall tops. The synthesis of sugar in the tops and its 

 translocation to the roots appeared to continue until the t'ops were killed 

 by frost. 



Destruction of the tops by rust, or their premature removal to be rid 

 of the berries, must lessen the amount of sugar which can be stored in 

 the roots. 



The fertilizing constituents which were stored in the roots over winter 

 appeared to be nearly, if not quite, sufficient for the full development of the 

 succeeding spring crop. There was evidence of a small intake of nitrogen 

 during the cropping season, and a pronounced absorption of lime and 

 sulfuric acid. 



Sulfuric acid was found to be equally, if not more, important than 

 phosphoric acid among the constituents of the asparagus plant. Never- 

 theless, the sulfate of lime in the acid phosphate appeared to suffice fully 

 for the needs of the crop. 



