Full resolution (JPEG) - On this page / på denna sida - Sidor ...
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
349
Table II. Second experiment (1923).
Caleiumconcentr. Relative values of average
correspond. to ratio dry-weights (i).
| + |
Tey ee ee ee 100 54
HL c. hp cs oo oh ae 73.7 9.0
IRM 5 c 5 5 vet: ELE (71.5)*
in RS rf & ma a 65.0 7.4
Moo c to Cb om 37.6 6.7
| ME Ss ELS e 26.9 | 24
N a non sou ot Se m. (16.2) *
* interpolated values (ef. p. 364).
The physiological disease, twice mentioned above, showed itself
as grey, brown-edged spots on the leaves, beginning at the base
of the blades, and a decreased turgescence, which caused some
leaves to break. This is the diagnosis of a disease of oats widely
spread in Sweden. (ARRHENIUS 1923, [2]. Only certain breeds
of oats are susceplible to the disease, one of which is Dala-
oats 0924. In the first experiment the spots were most abun-
dant on the plants grown in the solution with the ratio II
(Ca: Na—90: 10), less on those of I (Ca: Na—100: 0) and decreasing in
number until on the plants of VI (Ca: Na—10: 90) no trace of the spots
were found. "This, in conjunction with the fact that the optimal
ralio was found to be VI (see below) and that the acidity in all
’ases was the same and as relatively high as 10—55!9 9; seems to
confirm ARRHENIUS’ view of the cause of the disease, — if the fact
that the disease was stronger in II than in I may be thus explained,
that the plants of I, having the full supply of Ca as a food-sub-
stance, were more able to resist the disease than those of II. The
disease was formerly considered to be due to a high alkalinity,
its old Swedish name meant “alkalinity disease". Now-a-days it
is simply called “gräfläckssjuka“, that is *grey-spot-disease* (German
= "pórrfleckenkrankheit^). ARRHENIUS, who has made soil cul-
tures and field experiments, concludes that the principal cause of
the disease is too high a proportion of calcium to other ions; this
effect will be counteracted to a certain extent by sodium chloride
or sodium sulphate and more or less by other substances. The
<< prev. page << föreg. sida << >> nästa sida >> next page >>
