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J. J. SKINNER 



Vanillin was used in amounts of 100 to 500 parts per million- 

 It was applied to the soil by dissolving in water and mixing the 

 solution in the soil before potting. The results of the experiment 

 on the effect of vanillin in the Florida sand, Susquehanna sandy 

 loam, and Hagerstown loam are given in table 1. The actual 

 green weight of the plants grown in the two pots are given for 

 each treatment and the relative weight with the growth in the 

 untreated soil taken as 100. 



TABLE 1 



Effect of vanillin on wheat plants in pots grown in Florida sand, Susquehanna sandy 



loam, and in Hagerstown loam 



The vanillin was quite harmful in amounts of 400 and 500 

 parts per million in the Florida sand and was only moderately 

 harmful in amounts of 100 to 300 parts per million. With the 

 Susquehanna sandy loam the vanillin reduced growth consid- 

 erably when applied at the rate of 300, 400, and 500 parts per 

 million. It was slightly harmful with 100 and 200 parts per 

 million. Vanillin had no harmful effect in the Hagerstown loam 

 —two of the treatments were slightly above the check and three 

 slightly below. The growth in the untreated soil of the Hagers- 

 town loam was better than in the Susquehanna sandy loam and 

 considerably better than in the Florida sand. 



It is seen from this experiment that vanillin is harmful in two 

 of the soils and has no effect in the third. Vanillin is easily oxi- 

 dized and changed under favorable conditions, and if this took 



