MANGANESE CHLOROSIS OF PINEAPPLE. 
15 
Table 10. — Comparative weights of rice plants which were grown in nutrient solu- 
tions containing manganous sulphate and manganese dioxid solutions, to which 
iron as ferrous sulphate, ferric chlorid, and ferric citrate was added. 
Se- 
ries. 
Culture solutions with 
amount of added material 
per liter. 
Check; sol. +0.008 gm 
from FeS0 4 . 
Sol. +0.008 gm. 
FeSO 4 +0.072 
from MnS0 4 . 
Sol. +0.008 gm. 
FeSC-4+0.007 
from MnS04. 
Fe 
gm. 
Fe 
gm. 
Fe 
from 
Mn 
from 
Mn 
Flask 
No. 
Sol. +0.008 gm. Fe from 
FeSO 4 +0.4 gm. Mn0 2 . 
Sol.+0.008 
FeCl 3 . 
gm. Fe 
from ' 
1 
Ba 
B, 
C 
C 2 
C 3 
Sol. +0.008 gm. Fe from 
FeCls+0.007 gm. MnS0 4 . 
Fe from 
MnO,. 
Fe from 
Fe 
Sol. +0.008 gm. 
FeCh+0.4 gm 
Sol. +0.008 gm. 
Fe2(C 6 H 5 07)2. 
Sol. +0.008 gm. 
Fe 2 (C6H 5 O-)j+0.072 
Mn from MnS0 4 . 
Sol. +0.008 gm. Fe 
Fe2(C6H 5 O7) 2 +0.007 
Mnfrom MnS0 4 . 
Sol. +0.008 gm. Fe 2 (C 6 H 5 07) 2 
+0.4 gm. Mn0 2 . 
from 
gm. 
from 
gm. 
Bj Sol.+O.OOS gm. Fe from j 11 
FeCh+0.072 gm. MnS0 4 . \ 12 
™f ht wSt 
Ieaves - lelvl 
Grams, 
5.77 
6.01 
.80 
.72 
3.18 
2.38 
5.04 
4.66 
.23 
.27 
1.91 
1.42 
.15 
.20 
3.40 
4.94 
.11 
.08 
.25 
.29 
Grams. 
1.04 
1.03 
.20 
.20 
.65 
.07 
23 I .49 
24 | .49 
.87 
.85 
.38 
.04 
.06 
.56 
.79 
.04 
.03 
.06 
.10 
.12 
Oven- 
dry 
weight 
of 
roots. 
Grams. 
0.39 
.37 
.07 
.06 
.22 
' .19 
.04 
.05 
.31 
.25 
.04 
.04 
.15 
.14 
.04 
.04 
.20 
.31 
.04 
.04 
.04 
.04 
05 
Average oven- 
dry weight. 
S and S Whole 
lelves. P lant - 
Grams. Grams. 
1.04 
1.42 
.20 
.27 
.61 
. 81 
.07 
.11 
.86 
1.14 
.08 
.12 
.42 
.57 
.05 
.09 
.68 
.93 
.04 
.08 
.06 
.10 
.11 
.17 
Condition of plants , 
Green; healthy. 
Stunted; light-col- 
ored, spotted 
with brown. 
\Somewhat stunt- 
81 / ed; light-colored. 
"Very stunted; yel- 
low and bleached; 
spotted with 
brown. 
Green; healthy. 
Extremely stunt- 
ed; leaves with- 
ered; practically 
dead. 
IStunted; light-col- 
/ ored. 
ery stunted ; 
leaves almost 
white. 
[Green; healthy. 
W i t h e r e d and 
dead. 
Very pale greenish- 
yellow; leaves 
withered. 
Leaves yellow , 
spotted with 
brown. 
The form in which iron was supplied did not seem to change the 
effects of the manganese. As small an amount as 7 milligrams per 
liter of manganese as manganous sulphate (0.002 per cent of man- 
ganous sulphate) caused chlorosis and a very striking decrease in 
weight of plants. Manganese dioxid produced a similar effect. Fer- 
rous sulphate appeared to be the best source of iron supply, with 
ferric chlorid next, and ferric citrate last. 
Experiment III. — It was decided to investigate more thoroughly 
the effects of varying amounts of iron, because the effects of man- 
ganese seemed to depend largely on the iron content in the nutrient 
solution. Tests with nutrient solution which had been used in Ex- 
periment II were repeated. Two plants were grown in each flask, two 
flasks were taken as a unit, and the units were triplicated for each 
variable. Eighteen tests were made. 
The leaves of the plants in series A 4 , B 41 and C 4 were dipped in a 
0.5 per cent solution of ferrous sulphate several hours before the 
nutrient solutions were changed so as to minimize chances of the 
dipping solution getting into the nutrient solution. 
Representative plants of each trial were photographed on the for- 
tieth day just before harvesting. The weights of the harvested plants 
are given in Table 11 and graphically in Figure 1. 
