REPORT Oi" BOTANIST 



Wright A. Gardner 



Auburn, Ala., Jan. 18, 1919. 

 Director J. F. Duggar, 



Alabama Experiment Station, 

 Auburn, Ala. 

 Sir: 



I beg leave to submit the following report of experimental 

 work conducted by the Department of Botany during the past 

 year. 

 Adams Fund Projects. 



(1) Soil Toxin Project. Various claims have been made 

 with reference to the presence of poisonous substances in 

 soils. Some claim that poisonous substances are excreted by 

 the roots; others claim that they are products of the decompo- 

 sition of plant and animal tissue. The majority of those 

 interested in soil fertility investigations admit the presence 

 of these poisonous substances whether they consider them 

 important or not. The workers in the Bureau of Soils in 

 Washington have separated from soils several substances 

 poisonous to crop plants, such as wheat, corn and peas. The 

 workers in this laboratory have been seeking agencies and 

 conditions for the destruction of these injurious substances. 

 W. J. Bobbins, in Bulletin 204, The Destruction of Vanillin in 

 the Soil by the Action of Bacteria, June, 1918, shows that 

 certain bacteria decompose vanillin and points out several 

 conditions favorable to its decomposition. Two lines of in- 

 vestigation are now being carried on. One deals with the 

 relation of oxygen and water to the decomposition of vanillin 

 in the soils. Results so far obtained indicate that under soil 

 conditions an inadequate water supply is more freciuently 

 the limiting factor. The other investigation deals with the 

 decomposition of toxins by soil bacteria. Results obtained 

 indicate that many soils from Alabama and elsewhere, though 

 not all, contain organisms which decompose cinnamic acid, 

 resorcin, and vanillin, that some soils contain organisms which 

 decompose guanidine hydrochloride, piperidine. and cumarin. 



