Journal of Agricultural Research 
Vol. XXIII, No. 5 
384 
(3) The P H value of the juice of wheat plants grown in the greenhouse 
averages 0.1 higher when the plants are cut at 1 p. m. than when they 
are cut in the morning about 9 o’clock. 
(4) The hydrogen-ion concentration of the juice of wheat plants 
grown in limed soil is lower than that of plants grown in unlimed soil. 
(5) Lack of vigor as shown by unhealthy appearance of wheat plants 
is always accompanied by an abnormally high acidity of the expressed 
juice. 
(6) Plants badly infected with Erysiphe graminis are more acid than 
adjacent plants free from infection. This may be due to the poor physical 
condition of the plants and not to any direct effect of the presence of the 
fungus. 
(7) The geographic source of the seed does not affect the hydrogen-ion 
concentration of the juice of the plants. 
(8) The concentration of hydrogen ions in expressed wheat juice in¬ 
creases on standing. 
(9) Dilution of the expressed juice decreases the concentration of 
hydrogen ions, the addition of two volumes of water to one of juice in¬ 
creasing the P H value by 0.10 to 0.15. Young germinator seedlings are 
more highly buffered against dilution than older greenhouse plants. 
literature; cited 
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