Jan. 12,1924 
Water Requirement of Rust-Infected Wheat 
11 7 
a correlation between the total acidity of the cell sap of certain varieties 
of wheat and resistance to rust and smut; also that the total acidity 
(content of buffer substances) may be decreased by liming the soil. 
Should a similar correlation have existed in the plants constituting 
Culture IV of the present experiment, their “resistance” to rust must 
have been due to something other than the reaction of the sap. 
SUMMARY 
Marquis wheat was grown to maturity in quartz sand cultures supplied 
with various combinations of mineral nutrients added in solution. An 
artificial epiphytotic of leaf rust, Puccinia triticina, was induced in one 
series, and of stem rust, P. graminis triiici , in a second, while a third was 
maintained free from infection. 
Rust infection of either type resulted in lowered water economy of the 
host, whether the dry matter of entire tops or of grain is considered. 
The actual quantity of water transpired is of significance in relation to 
infection only when the correlative production of dry matter is taken 
into account. 
The addition of NaCl or NaH 2 P 0 4 to the basic three-salt nutrient 
solution did not affect the susceptibility of wheat to leaf rust or stem 
rust. The addition of NaN 0 3 resulted in somewhat readier infection 
in each case but did not predispose to greater injury. KC 1 retarded 
infection in proportion to the diminution of growth of the host, partic¬ 
ularly when used in excess. CaCl 2 and MgCl 2 appeared to induce a 
state in which the host was less readily susceptible to infection. CaCl 2 
also resulted in a reduction of water requirement, about 10 per cent for 
tops and 40 per cent for grain. 
The addition of 0.0085 an d 0.0171 gram molecule of NaN 0 3 per liter 
and 0.0171 gram molecule of CaCl 2 caused an increase in yield over that 
obtained from the Shive solution as here used. 
LITERATURE CITED 
(1) Blackman, V. H. 
1919. THE COMPOUND INTEREST LAW AND PLANT GROWTH. In Ann Bot., V. 33, 
p* 353-360. 
(2) Blodgett, F. H. 
1901. transpiration op rust-infested rubus. In Torreya, v. i, p. 34-35. 
(3) Briggs, Lyman J., and Shantz, H. L. 
1913. THE WATER REQUIREMENT OF PLANTS. I. INVESTIGATIONS IN THE GREAT 
plains in 1910 and 1911. U. S. Dept. Agr. Bur. Plant Indus. Bui. 
284, 49 p., 2 fig., 11 pi. Literature cited, p. 49. 
(4) - 
1913. THE WATER REQUIREMENT OF PLANTS. II. A REVIEW OF THE LITERATURE. 
U. S. Dept. Agr. Bur. Plant Indus. Bui. 285, 96 p., 6 fig. Literature 
cited, p. 93-96. 
(5) -- 
1914. relative WATER REQUIREMENT of plants. In Jour. Agr. Research, 
v. 3, p. 1-63, 1 fig., 7 pi. Literature cited, p. 62-63. 
(6) Burgerstein, Alfred. 
1904-1920. die transpiration der pflanzen. 2. Teil. Jena. Literatur- 
nachweise, Teil 1, p. 251-283; Teil 2, p. 236-264. 
(7) Burkholder, W. H. 
1920. the effect of two soil temperatures on the yield and water 
relations of healthy and diseased bean plants. In Ecology, v. 
I, p. 113-123, illus. 
(8) DuFr^noy, J. 
1918. LES FACTEURS PHYSIQUES DE la TRANSPIRATION CHEZ LES PLANTES ET 
LA TRANSPIRATION DES FEUILLES PARASITES. In Rev. G6n. Sci., 
ann. 29, p. 565-566. 
