284 
Journal of Agricultural Research 
Vol. XXVIII, No. 3 
centration was near 2,200 parts per million. This was also the concentration 
at which the ratio of transpiration to dry weight was lowest. 
(3) Young orange trees grown in sand cultures supplied with nutrient solu¬ 
tions containing 364, 727, and 2,908 parts per million of solutes made practically 
the same amount of growth in each of the last two concentrations mentioned. 
The percentage of ash in the dry matter was greatest in the case of trees which 
received the most concentrated solution. The composition of the ash showed 
less tendency to vary than in the case of seedlings grown in water cultures, though 
there were some well-defined differences in the ash of rootlets. 
(4) The water-soluble inorganic constituents of the dry matter were usually 
greater in the case of trees which received the more concentrated nutrient solu¬ 
tions. Certain exceptions were found in the case of calcium. There seems to 
be no evidence in support of the assumption that the absorbed materials are 
converted into insoluble compounds as rapidly as they accumulate in the plant 
nor that absorption necessarily depends on the precipitation of ions within the 
plant. The nature of injuries which orange trees often exhibit when grown in 
saline soil may be related to the fact that the percentage of soluble sodium 
compounds appears to rise faster than the percentage of soluble calcium com¬ 
pounds. 
(5) The solubility of the inorganic constituents of the dry matter varied con¬ 
siderably in various parts of the tree. The highest percentage of soluble materials 
was found in the dry matter of the leaves, and the next highest, with the excep¬ 
tion of phosphates, in the rootlets. The lowest percentage of soluble materials 
usually occurred in the trunk and root. In other words, the greatest proportion 
of soluble materials was found in the parts of the tree in which the most active 
metabolism occurs. 
LITERATURE CITED 
(1) Cummins, A. B., and Kelley, W. P. 
1923. THE FORMATION OF SODIUM CARBONATE IN SOILS- Calif. AgT. 
Exp. Sta. Tech. Paper 3, 35 p. 
(2) Haas, A. R. C. 
1920. studies on the reaction of plant juices. Soil Sci. 9: 341-368, 
illus. 
(3) Reed, H. S., and Haas, A. R. C. 
1923. GROWTH AND COMPOSITION OF ORANGE TREES IN SAND AND SOIL 
cultures. Jour. Agr. Research 24: 801-815, illus. 
(4 ) - 
1923. effect of sodium chlorid and calcium chlorid upon growth 
AND COMPOSITION OF YOUNG ORANGE TREES. Calif. Agr. Exp. 
Sta. Tech. Paper 4, 32 p., illus. 
(5) - 
1923. studies on the effects of sodium, potassium, and calcium on 
young orange trees. Calif. Agr. Exp. Sta. Tech. Paper 11, 
32 p., illus. 
(6) Truog, E. 
1922. the feeding power of plants. Science 56: 294-299. 
