USE OF IRON IN NUTRIENT SOLUTION 
481 
The next series have the same concentrations of iron, ex- 
cept that the iron is in the ferrous form. The results presented 
graphically in figure 96 show that No. 4, with .0025 grams of 
Weight 
of crop ^ 
in grans' 
(36 pi- 1 
ants ) 
THE E FFECT OF FERR OU S PH OSPHATE JT^ONJTIffl' 
'GROWT H OF CANADA FIELD ' PEA SEEDLINGS . 
(TOTAI, SHOP) 
7.0000 
6.0000 
5.0000 
4.0000 
3.0000 
g 
.? = p * 
• u 
a M - 
^ oArv 
<-* CM 1CM>- 
O O O O 
.+> ,.o o. o 
I 04 ro^t ITVC 
4 5 
Figure 98 
ferrous phosphate (Fe 2 (P0 4 ) 3 , is the best in the series. The 
total yield is only 2.1778 grams (dry weight). This is much 
less than in the previous case. Solutions Nos. 5 and 6 give 
yields that are still smaller in amount. 
31 
