22 2 
Smith and Butler. — Relation of 
potassium starvation remaining were slight marginal chlorosis and drying of 
the cotyledons. The plants growing in the solution to which potassium was 
added after nine days were undersized and had poorly developed inflor- 
escences, but the only symptoms of potassium starvation were on the 
cotyledons, which were affected with marginal chlorosis. The plants 
growing in the solution to which potassium was added on the twelfth day 
were much dwarfed, only two nodes having developed and the cotyledons 
were chlorotic and possessed more or less dry revolute margins, but only in 
a few cases were the margins of the leaves chlorotic. The plants growing 
in the potassium-free solution possessed one short node and a miniature 
Table XXX. Effect of delayed additions of potassium on the amount of 
potassium present in Japanese buckwhe at grown in water culture . 
Nutritive solution 
used. 
Solution F. 
Solution F, less 
potassium. Potas- 
sium added after 3 
days. 
Solution F, less 
potassium. Potas- 
sium added after 6 
days. 
Solution F, less 
potassium. Potas- 
sium added after 9 
days. 
Solution F, less 
potassium. Potas- 
sium added after 12 
days. 
Solution F. Po- 
tassium absent. 
No. of 
plants. 
A mount of potassium 
in 
Tops. Roots. “ 
Potassium 
utilized per 
gramme of dry 
matter 
formed. 
Tops. Roots. 
Ratio of 
potas- 
sium 
content 
of tops 
to 
roots. 
Total 
potas - Potassium 
shim absorbed 
utilized from the 
per nutritive 
gramme solution 
of dry by one 
matter plant, 
formed. 
Mg. 
Mg. 
Mg. 
Mg. 
Mg. 
Mg. 
Mg. 
Mg. 
16 
16 
212-7 
204-8 
24-3 
20-9 
237-0 
225.7 
56-48 106-60 
59-75 9i-95 
0-52 
0-64 
59-34 
61.76 
14.74 
14.04 
16 
99- 1 
13-3 
1 1 2.4 
55-82 
86.81 
0-64 
58-31 
6-96 
16 
54-4 
7-7 
62-1 
51.46 
78.65 
0-65 
53-7^ 
3.82 
t6 
32-9 
4-7 
37-6 
48-65 
76.76 
0-63 
50-97 
2.29 
16 
2-6 
i-4 
4.0 
6.28 
40.46 
0.15 
8.91 
o-i8 
leaf. The root systems of all the plants except those growing in the full 
nutritive solution showed a dwarfing which was the more marked the longer 
potassium was withheld. 
The differences just described are well brought out in the data 
presented in Table XXIX. It will be noticed that the plants growing in 
the full nutritive solution and in the solution to which potassium was added 
after three days were able to grow relatively better tops than the plants 
growing in the other solutions, all of which behave in a very similar manner. 
Recovery, which was detected in the growth measurements, is not so 
