Oct., 1922] TURNER EFFECTS OF CERTAIN MINERAL SALTS 
Table i 
Fertilizer Treatment Moisture in Soil 
None 30% 
None 15% 
Complete 30% 
Complete 15% 
Complete with high nitrogen 30% 
Complete with high nitrogen 15% 
Ratio of Tops to Roots 
at Maturity (Wheat) 
8.1 
3-1 
8.7 
4.1 
9.8 
2.9 
It will be seen from table i that fertilizer and moisture appear to in- 
crease the ratio of tops to roots, but that the fertilizer factor plays appar- 
ently a small role in comparison with moisture. 
More or less recently three workers, Tottingham (31), Brenchley (2), 
and Stiles (29), employing nutrient solutions, have given considerable 
attention to the relative behavior of tops and roots of plants growing in 
solutions. But such attention as was given was only a side issue and not 
the primary aim of their investigations. Because of certain points of 
similarity running through the works of these three authors, it seems ad- 
visable to discuss them together. Both Stiles and Miss Brenchley sought 
to determine the effect upon growth of certain plants by varying the con- 
centration of the nutrient solution. They disagree sharply as to the range 
of concentration of nutrients in a solution which will offer favorable growth 
for plants, yet their results agree fairly well in respect to what they interpret 
as the effect of concentration on the ratio of tops to roots, and the fact has 
been pointed out more than once in their works that as the solution decreases 
in concentration, the ratio of dry weight of tops to roots also decreases. 
Table 2, taken from their results, brings out these findings. 
Table 2 
Concentration 
Full 
Strength 
i/S 
i/io 
1/20 
Duration 
Treatment 
Stiles 
4.0 
37 
34 
3-0 
39 
days 
Changed often 
Roots 
3.0 
31 
3-3 
2.5 
41 
days 
Changed twice 
' Roots 
^^ Tops 
2.7 
3-2 
3-1 
2.2 
42 
da3'S 
Changed once 
^' Roots 
Brenchley 
^ . Tops 
Series i, 
2.7 
2.5 
2.4 
2.5 
49 
days 
Changed often 
Roots 
3-7 
2.7 
1.8 
1.5 
Changed once 
2.6 
2.2 
1.8 
1.2 
Changed never 
3-3 
3-0 
2.3 
1.9 
49 
days 
Changed often 
' Roots 
2.8 
2.3 
1.8 
1.4 
Changed once 
2.6 
1.8 
1-3 
I.O 
Changed never 
^ Tops 
3-9 
3-1 
2.8 
2.4 
49 
days 
Changed often 
^' Roots ■ ■ ■ ■ 
2.3 
2.3 
1-9 
1.6 
Changed once 
1.9 
1-3 
1.2 
1.0 
Changed never 
