HARMFUL EFFECTS OF ALDEHYDES IN SOILS. 7 
The green weights taken at the termination of the experiment were 
8.5 grams from the control pot and only 4.2 grams from the salicylic 
aldehyde treated pot, a decrease of approximately 50 per cent. 
In the foregoing salicylic aldehyde has been shown to be harmful 
to wheat and rice seedlings in distilled water, to wheat, corn, cowpeas, 
cabbage, and rice in nutrient solutions, and to wheat, corn, and clover 
in soil in pots. 
EFFECT OF SALICYLIC ALDEHYDE IN SOLUTION CULTURES WITH 
VARIOUS FERTILIZER INGREDIENTS, 
EFFECT ON WHEAT. 
The effect of salicylic aldehyde on wheat plants was further studied 
by growing the seedlings in nutrient culture solutions containing the 
ordinary fertilizer salts, calcium acid phosphate, sodium nitrate, and 
potassium sulphate. Some of the cultures contained calcium acid 
phosphate only, some sodium nitrate only, and some potassium sul- 
phate only. Other solutions were composed of mixtures of two 
salts, calcium acid phosphate and sodium nitrate, calcium acid \A\os- 
phate and potassium sulphate, and sodium nitrate and potassium 
sulphate. Still other solutions had all three constituents in various 
proportions. The compositions of the various solutions is given in 
the first three columns of the tables which are to follow. 1 Two sets 
of cultures were prepared; to one set were added merely the nutrient 
salts; to a similar set 10 parts per million of salicylic aldehyde were 
added in each culture in addition to the nutrient salts. The culture 
solutions were changed every three days, four changes being made 
in the course of the experiment. The solutions were analyzed for 
nitrates immediately after each change. The phosphate and potas- 
sium were determined on a composite solution of the four changes. 
The culture grew from May 15 to May 27, 1912. 
When the plants had grown for several days, it was noticeable that 
the salicylic aldehyde cultures were developing more slowly. Each 
of the cultures seemed affected, regardless of the composition or the 
proportion of the nutrient salts. 
When the plants had grown for 12 days with four changes of the 
solutions, the green weights were taken. The results obtained with 
the solution of different fertilizer ingredients are grouped in the tables 
which follow, so as to bring together those cultures which were com- 
posed principally of phosphate, those which were composed princi- 
pally of nitrate, and those composed principally of potassium salt. 
In each group there were 21 cultures. A fourth group, comprising 
six cultures, is also given. It includes those cultures with a nearly 
equal proportion of the three salts. 
1 The solutions were prepared as described in Bui. 70, Bureau of Soils, U. S. Dept. of Agriculture. 
