VANILLIN AS A SOIL CONSTITUENT 



327 



Four applications of vanillin wore made. The first on May 

 20, one day before the planting of seed. The other three appli- 

 cations were made periodically during the growth of the crops — 

 May 28, June 5, and June 24. The vanillin was applied by dis- 

 solving in water and sprinkling the solution uniformly on the 

 surface of the ground before planting, after which the soil was 

 raked thoroughly. The remaining applications were made after 

 planting by sprinkling the solution between the rows of plants, 

 the soil being subsequently cultivated. The total application 

 was at the rate of 284 pounds per acre, in four equal parts. 



TABLE 2 



Yield of cowpeas, garden peas and string beans as affected by vanillin in the field 



(yield per plot) 



The crops germinated uniformly. The effect of the vanillin 

 was noticeable from the beginning and throughout the experi- 

 ment. The growth was stunted, though the plants grew slowly to 

 maturity, and were harvested. The three crops were sown on 

 their respective plots May 21. The cowpeas were harvested 

 September 27, the garden peas had matured by June 30, and 

 were harvested on that date, and the string beans were harvested 

 July 22. The yields of the various plots are given in table 2. 



An examination of the table shows that vanillin checked growth 

 and materially lessened the yield, with each of the crops. In the 

 case of the cowpeas there was a reduction of 33% of green vines 

 and 39% of cured hay. The garden peas were reduced 30% in 



