COMMERCIAL PEODUCTION OF LEMON-GEASS OIL. 



9 



Time of harvest. — Since lemon grass is a perennial crop and two or 

 three cuttings can be made each year, it is of interest to note the 

 difference in yield of oil secured from the plants at each harvest. In 

 Table IV are given the results obtained from each of two harvests 

 for various years. 



Table IV. — Yield of lemon-grass oil distilled from plants harvested at two different times 



of the year. 



Year and plants har- 

 vested. 



Yield of oil. 



Yeai' and plants har- 

 vested. 



Yield of oil. 



First 

 harvest. 



Second 

 harvest. 



First 

 harvest. 



Second 

 harvest. 



1908. 



Per cent. 



0.31 



.40 



.20 



.40 



.28 



.37 

 .34 

 .16 



Per cent. 



0.33 



.48 



..35 



.36 

 .46 



..50 

 .35 

 .20 



1914— Continued. 

 No.8 



Per cent. 



0.12 



.24 



.27 

 .11 



.19 

 .23 

 .28 

 .29 

 .12 



Per cent. 

 0.38 





No. 9 



.36 



Third plat 



1915. 

 No.l 





1912. 



.26 



No. 1 



No.8 



.11 



No.8 



No.9 



.17 





No. 10 



.47 



1914. 



No. 11 



No. 12 



.40 

 .31 





No. 13 















No.6 









These residts show that in general the percentage of oil is higher 

 in the second cutting. In the first year of planting, however, the 

 quantity of herb obtained in the second cutting is much less than 

 that from the first cutting; consequently, the acre yield of oil in the 

 first year would be greater from the first cutting rather than from the 

 second. 



FACTORS AFFECTING THE CITRAL CONTENT OF LEMON-GRASS OIL. 



Closeness of cutting the plants. — Experiments conducted with 

 variety No. 1, grown on very light sandy soil, showed that the citral 

 content was highest in the part of the plant nearest the ground. 

 Large plants divided into three portions yielded, on distillation, oil 

 witli citral content as follows: Upper portion, 70 per cent; middle 

 portion, 78 per cent; and lowest portion, 82 per cent. A similar test 

 made with variety No. 5 divided into only two portions yielded oil 

 with citral content in favor of the lower portion, as follows: Upper 

 portion, 74 per cent; lower portion, 76 per cent. These results show 

 that the clos(;st cutting which gives a profitable yield of oil also pro- 

 duces a better quality of oil. 



Soil nujisture. — Plants of variety No. 1 , grown on soils having vary- 

 ing degrees of moisture, yielded oil witli citral content as follows: 

 On dry sandy soil, 75 per cent citral; on slightly moist sandy loam, 

 68 p(!r cent; and on moist loam near th(^ lake, 66 ])er cent. Further 

 tests with other varieties <in difrcn-iit lyjx's of soil liav<> given similar 



