8 
BULLETIN 442, U. S. DEPARTMENT OF AGRICULTURE. 
Table III shows the variations in the yield of oil and the citral con- 
tent of the oil from these various types for the season of 1915. 
Table III. — Yield and citral content of lemon-grass oils distilled from the various plants 
under cultivation in 1915. 
Variety. 
Yield of oH. 
Citral con- 
tent of the 
oil. 
Variety. 
Yield of oil. 
Citral con- 
tent of the 
oil. 
No. 1 
Per cent. 
0.24 
.27 
.16 
.23 
.15 
Per cent. 
80 
70 
73 
72 
79 
No. 9 
Per cent. 
0.20 
.23 
.28 
.29 
.12 
Per ant. 
76 
No. 5 
No. 10 
80 
No. 6 
No. 11. 
80 
No. 7 
No. 12... 
81 
No. 8 
No. 13 
85 
It has been found year by year that there is considerable variation 
in both the yield of oil and the citral content, yet the figures given 
in Table III may be taken as representative of the varieties men- 
tioned. It will be noted that the Ceylon forms, Nos. 6 and 13, are 
very low in oil yield, and the same is true of No. 8, from India. 
Both the yield of oil and the citral content of the oil have been 
found to be affected to a considerable degree by the type of soil on 
which the plants are grown. Therefore, before selecting a variety 
for commercial planting, tests should be made to determine which 
variety will give the highest yield of oil per acre and the highest 
citral content on the land to be used. The vigor of the plants should 
also be considered, since there seems to be a difference in soil require- 
ments among the varieties tested. 
FACTORS AFFECTING THE YIELD OF LEMON-GRASS OIL. 
Soil conditions. — In order to determine the effect of soil conditions 
on the yield of lemon-grass oil, tests were made in 1908 with the West 
Indian variety, No. 1, on soils containing various degrees of moisture. 
On light sandy soil of the high hammock type the yield of oil was 
0.31 per cent, and on moist bottom land 0.27 per cent. Another test 
on sandy high pine land in a different location gave an oil yield of 
0.35 per cent, and on moist land near the lake 0.28 per cent. Further 
tests with this variety under other conditions of soil moisture gave 
results which were also much in favor of the sandier and better 
drained land. In 1915 the plat devoted to the Ceylon variety, No. 6, 
showed a higher yield of oil from the plants grown on the high, 
well-drained, sandy soil than from the part of the plat which con- 
tained slightly more moisture, 0,16 per cent being obtained from the 
former and only 0.11 per cent from the latter. Similar results were 
secured in 1914 with varieties Nos. 5, 8, and 9. 
The evidence thus far available indicates that for all the forms of 
lemon grass tested, a heavy growth of herb with high oil content is 
to be expected on light, well-drained soil of the high pme type. 
