92 



Journal of Agricultural Research voi. xviu. no. 2 



AIR-DRY WEIGHT PER PLANT." 



o Based on lo plants. 



The conclusion may be drawn from the foregoing observations that the 

 greater concentration or supply of one or more ions present during the 

 later stage^ prolongs the period of vegetative growth and possibly inter- 

 feres with the processes of ripening, without producing any large increase 

 in yield. 



ofij^/a/A/^i SO/..JZTJ 



^Oe/G/AML so^.j^ 



'^foe/s/AC^A sat.T.) 



£>fys. 



Fig. 3. — Water cultures, series 2. Graph showing absorption of nutrients from solutions of three con- 

 centrations during latter part of growth cycle. Solutions not changed during the final 80 days. 



The absorption was followed each week by means of conductivity 

 measurements, by removing portions of solutions from the culture bottles 

 after adding water to restore the original volume. The solution was 

 thoroughly mixed by passing a current of air through it. After the 

 conductivity was determined the samples were returned to the original 

 bottles. The course of absorption is graphically indicated in figure 3. 

 The data are calculated to percentages of total electrolytes absorbed 



