5an. i2,1924 
Water Requirement of Rust-Infected Wheat 
115 
EFFECT OF CERTAIN MINERAL NUTRIENTS ON DEVELOPMENT OF 
RUST AND INJURY TO HOST 
The original plan of this investigation included an extensive study of 
the effect of mineral nutrition upon the host as regards its susceptibility 
to rust infection and the injury it suffers therefrom. Owing to the fact 
that it was not possible to repeat the experiment described in Part I of 
this paper, or to extend the investigation along different lines, it seems 
best to draw no conclusions in respect to these questions from the limited 
data at hand. Certain tendencies were noticeable, however, as regards 
the performance of the plants under some of the treatments, and the 
data from all cultures which attained approximate maturity are pre¬ 
sented in Table IV, arranged to show the effect of the mineral nutrients 
on the yield and quantity of rust. 
Table IV. —Influence of different culture media on average yield and water requirement 
of two cultures of Marquis wheat , one rusted and one rust-free , each consisting of four 
replicate crocks 
Yield. 
Water requirement. 
Aver¬ 
age per 
Culture. 
Tops. 
Grain. 
Water 
used. 
Tops. 
Grain. 
centage 
of rust 
for two 
infected 
cul¬ 
tures. 
00. 
Gm. 
i9.8l8io.822 
Gm. 
2. 754 ±o -326 
Cc . 
6 , 6 s 7±274 
33 <>± 
5-9 
2,6oo± 258 
17 
OA. 
X7- 588^1.095 
i.7o6± .361 
6,342±2i8 
35o±io7.o 
S,i 54 ± 173 
24 
OB. 
20.215 i .703 
2. on ± .291 
6 , 579 ±i 25 
33 2 ± 
8.1 
4,443 ±1,043 
25 
IA. 
23* 147 ± *494 
2.298± .387 
7,107 ±169 
6,8i3±i32 
302 ± 
10.4 
31913 ±1,044 
42 
IB. 
23.638^ .326 
i- 377 ± .261 
292 ± 
7.2 
7,623 ±3,567 
3 1 
IIA<*. 
20.997 ±1.028 
i.653± .228 
6,639 ±205 
3 2I ± 
9-7 
5 , 3 ° 5 ±i> 57 8 
13 
IIB a . . .. 
i8.3oo± .321 
i.o75± .428 
6,276±io6 
345 ± 
8.3 
6,746± 402 
23 
IIIA&. .. 
i9-6i2± .794 
i- 335 ± -397 
6,267±i76 
320± 
4.7 
7 > 765 ± 753 
3 
IVB. 
21.024± .478 
4 - 343 ± - 3°5 
6,090±i9i 
290 ±104.0 
1,522 ± 136 
10 
VB. 
19.002 ±1.204 
I. 702 ± .427 
5,687 ±208 
307 ± 
8.0 
3 ,856± 587 
8 
a Data for leaf rust series omitted owing to immaturity of the plants. 
6 Series IIIB, with excess KC 1 , omitted owing to immaturity. 
Even a greatly curtailed review of the literature of transpiration 
dealing with the effects of nutrient ions and other substances and the 
state of fertilization upon the water relations of plants, will not be 
attempted here. Briggs and Shantz (3, 4) have given a very thorough 
review of the literature dealing with water requirement based on mature 
growth of plants, and a bibliography of papers containing water require¬ 
ment measurements based on seedlings. A large number of papers 
dealing only wfith rate of transpiration as affected by various sub¬ 
stances, of nutritive value and otherwise, is included in the compre¬ 
hensive review of the subject of transpiration by Burgerstein (6). The 
literature dealing with the effect of fertilization on the severity of rust 
is reviewed by Raines ( 12 ). 
Briggs and Shantz conclude that a reduction in the w T ater require¬ 
ment results from the use of fertilizers, although very little difference 
in this respect is shown by highly productive soils. A highwater 
requirement may result from deficiency of a single nutrient element, or 
in fact from any condition which operates to limit or retard growth, as 
measured by carbon assimilation, while transpiration suffers no corre¬ 
sponding change. Furthermore, a highwater requirement may be 
