128 



Journal of Agricultural Research voi. xxn. No. 3 



LOCALIZATION OF HYDROCYANIC ACID IN THE PLANT 



At three different times the grass was divided into leaves and stems. 

 From 200-gm. portions the number of milligrams of hydrocyanic acid 

 shown in Table IV were obtained. 



Table 1\ . — Hydrocyanic acid in leaves and stem s of Sudan grass 



Date collected. 



June 30 

 July 7.. 

 July 21. 



stems. 



Mgm. 



Trace. 



The immaturity of the sample collected June 30 accounts for the moder- 

 ate amount obtained from the stems. At a later date two tests were made 

 on immature heads. No hydrocyanic acid was found. In the following 

 tests reported in this paper leaves only were used unless otherwise stated. 



INFLUENCE OF STAGE OF GROWTH 



Since grass was cut almost every week throughout the summer there 

 were afforded several opportunities to test the comparative amounts 

 present in various stages of growth and development. The shorter grass 

 was obtained from plants which had been cut once or several times. 



Table V. — Hydrocyanic acid in Sudan grass at different dates and stages of growth 



Date collected. 



Portion used. 



Average height. 



HCN. 



July 22. 



26. 



Aug. 12 

 27. 

 30 



Whole plant. 



....do 



....do 



Leaves 



....do 



....do 



Whole plant. 



do 



do 



Leaves 



do 



do 



do 



I Whole plant. 

 Leaves 

 do 



(Whole plant, 

 do 

 Leaves 

 do 



fWhole plant. 

 \Leaves 



(Whole plant, 

 do 

 Leaves 

 do 



6 inches 



8 inches 



12 inches 



18 inches 



24 inches 



30 inches 



4 inches 



6 inches 



12 inches 



Beginning to head 



Partly headed 



Fully headed 



Partly dead 



4 inches 



16 inches 



Headed 



4 inches 



10 inches 



15 inches 



24 inches 



5 inches 



20 inches 



2 inches 



12 inches 



Ready to head. .. . 

 Blooming 



Mgm. 

 27 



19 



7 

 24 

 20 



9 

 40 



32 

 10 

 12 



17 

 20 

 6 

 II 

 18 



19 



40 



12 



16 



10 



10 



II 



5 



5 



9 



10 



