Lecture 4 



— 77 — Movement and Distribution 



We can also make experiments bearing on the 

 general problem under discussion by comparing the 

 amounts of salt absorbed and translocated over a lim- 

 ited time period by young barley plants held in one 

 case in the dark in a highly humid atmosphere, and 

 in another, exposed to illumination and to relatively 

 low humidity of the atmosphere, inducing high trans- 



TOTAL Bf HV3 ABSORBCO 



R IN SWXU K IN ROOT Br IN a-KWT 0r IN ROOT TOTAL 

 L.H MM L H. MM. LK H H. L.M MM. L.M H_ _ _ 



(,K>*T DARK UOfT DARK LiOT DARK LOT DARK. LCMT OARK. LCmT CARK LOT DARK 



Textfigure 19. — Absorption of K and Br by young 

 barley plants over a short experimental period (12 hours). 

 Some plants were illimiinated and in a relatively dry at- 

 mosphere; others were placed in darkness in a very 

 humid atmosphere. Large differences in water absorption 

 are shown, but there are no corresponding effects on 

 salt absorption. (Broyer and Hoagland). 



piration. When experiments of this kind are made 

 with barley plants of low initial salt status and high 

 in sugar content, the total salt absorption may be 

 approximately the same under the two widely different 

 environments. Further, the general distribution of 

 salt between the root and the shoot may not be greatly 

 affected by the aerial environment, although within 

 the shoot itself the salt may be distributed differently 



