8 



BULLETIN 108, U. S. DEPARTMENT OF AGRICULTURE. 



Table IV gives the growth in cultures composed principally of 

 phosphate, without and with 10 parts per million of salicylic aldehyde. 

 The composition of the culture solution is given in the first three 

 columns. As will be seen, the solutions contained principally phos- 

 phate, but also varying smaller amounts of nitrate and potash. In 

 the fourth column is given the green weight of the plants grown in 

 solutions which contain no salicylic aldehyde, and in the fifth column 

 the weight of the plants in solutions containing 10 parts per million 

 of salicylic aldehyde. 



By comparing these two columns in the table it is seen that the 

 green weight of the salicylic aldehyde culture is less in every case, 

 with one exception only, than the green weight of the culture of the 

 same fertilizer mixture without the salicylic aldehyde. The total 

 green weight of the 21 normal, or control, cultures was 39.61 grams, 

 against 31.74 grams for the 21 cultures with salicylic aldehyde. 



Table IV. — Effect of salicylic aldehyde on wheat in nutrient culture solutions composed 



principally of phosphate. 







With 







With 



Composition of culture 

 solution. 



Without 

 salicylic 

 aldehyde . 



salicylic 

 aldehyde, 

 10 parts 



per 

 million. 



Composition of culture 

 solution. 



Without 

 salicylic 

 aldehyde . 



salicylic 



aldehyde , 



10 parts 



per 

 million. 



P2O5 



NH 3 



K 2 



Green 



weight. 



Green 

 weight. 



P2O5 



NH 3 



K 2 



Green 



weight. 



Green 

 weight. 



Parts per 



Parte per 



Parts per 







Parte per 



Parte per 



Parte per 







million. 



million. 



million. 



Grams. 



Gram.s. 



million. 



million. 



million. 



Grams. 



Grams. 



80 











1.02 



0.76 



48 



8 



24 



2.50 



1.54 



72 







8 



1.32 



1.04 



48 



16 



16 



2.60 



1.92 



72 



8 







1.30 



1.14 



48 



24 



8 



2.50 



1.88 



64 







16 



1.32 



1.22 



48 



32 







1.64 



1.34 



64 



8 



8 



1.70 



L44 



40 







40 



1.75 



1.10 



64 



16 







1.54 



1.14 



40 



8 



32 



1.90 



1.52 



56 







24 



1.24 



1.38 



40 



16 



24 



2.98 



2.16 



56 



8 



16 



2.34 



1.52 



40 



24 



16 



2.88 



2.14 



56 



16 



8 



2.04 



1.66 



40 



32 



8 



2.28 



1.74 



56 



24 







1.34 



1.2S 



40 



40 







1.80 



1.60 



48 







32 



1.62 



1.22 













Table V gives the results of salicylic aldehyde in nutrient solution 

 in which the principal ingredient is nitrate. 



As seen in the fourth and fifth columns of the table, the growth 

 in cultures with salicylic aldehyde are much smaller than the growth 

 in solutions containing merely the nutrient salts. The total green 

 weight of the 21 cultures in nutrient salts was 49.36 grams, and the 

 green weight of the 21 nutrient cultures containing 10 parts per 

 million salicylic aldehyde was only 36.11 grams. From these figures 

 it is seen that salicylic aldehyde in these nutrient solutions, princi- 

 pally nitrogenous, as in the phosphate solutions, is quite harmful 

 to wheat plants. 



