RELATION OF TRANSPIRATION TO GROWTH IN 
WHEAT. 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY. 
LXXVII. 
BuRTON EDWARD LIVINGSTON. 
(WITH TWENTY-ONE FIGURES) 
INTRODUCTION. 
TRANSPIRATION being a continuous phenomenon in living plants, 
and being at the same time readily measurable, it has been suggested 
by Warrney and Cameron’ that here is a criterion for comparing 
the rates of growth of similar cultures made in different media. It 
was found at the start that when two cultures of wheat seedlings were 
prepared, exactly alike except that one was in a good soil and another 
in a poor, the total transpiration for a period of ten days or more 
was invariably much greater in the former culture, the difference 
between the two amounts of water lost being roughly equivalent © 
the difference between the agricultural values of the soils. It was 
deemed worth while to investigate this fact more carefully, and the 
present paper embodies the results of such investigations. : 
The Russian variety of wheat known as “chul” was used 1m 
these experiments. The soil cultures were grown in wire baskets 
covered with paraffin, such as those described in the pape cited ; 
above. For any one series the initial moisture content of all the 
was the same, being about the optimum for plant growth under ss a 
conditions of the experiment. The transpiration was determined a 
daily, or at intervals of four days or less, by the method of weighing e 
and the necessary amount of water was then added to bring Lok ; 
soil back to its original moisture content. The baskets of any sere 
stood side by side in a plant house, being thus subjected to exacly 
the same changes in temperature, humidity, light, and air ct 
Six wheat seedlings were grown in a basket. 
HITNEY, M.and Camerox, F. K. Investigations in soil fertility. ©: : q 
Department of Agriculture, Bureau of Soils, Bull. 23. 1904- 
178 
