Lecture 5 



109 



Artificial Media 



same good soil; or often in the same nutrient solu- 

 tion. 



It can be argued that every change in composition 

 of a nutrient solution, however slight, might produce 

 some changes in relative absorption of nutrients by 

 the plant and in yield. This could be granted, at the 



J 5 



to 



> 



t 4 



Q March 22- May 6 

 ^ May 6 — July 7 

 I July 7 — Aug. 24 



Ca 



K 



Textfigure 31, — Average daily absorption of nutrient ele- 

 ments from an aerated solution by a tomato plant, at various 

 stages of growth, including fruiting stage. Quantitatively, nitro- 

 gen is of dominant importance; then follows potassium. The 

 absorption of calcium was, however, slightly higher than that 

 of potassium in the fruit stage of growth. (From Arnon and 

 HOAGLAND, 1940). 



same time suggesting that it might not be worth 

 while, or even feasible, to establish small statistically 

 valid differences in yield at the expense of a large 

 amount of labor. The results, in any event, would 

 be different for every different climatic complex. On 

 the other hand, the inorganic composition of a plant 



