WATER SATURATION DEFICIT iii 



between the third and sixth hour of estimation, this error cannot be 

 eHminated by extrapolation. On the other hand, the very small differences 

 in WSD values obtained by extrapolation in young and old leaves of fully 

 turgescent plants oppose this possibility. The solution of this problem must 

 be postponed to further work. 



ACKNOWLEDGMENTS 



It is my pleasure to thank Dr. B. Slavik for the interest he has taken in the 

 work described and for many valuable discussions on the topic. My thanks 

 are due to Mrs. Mandlova for skilled technical help. 



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