COMMERCIAL PRODUCTION OF LEMON-GRASS OIL. 5 
continue to grow throughout the summer, it has been found that 
after a certain size has been reached the increase in weight is less 
rapid; hence, it is more profitable to harvest the crop at the time 
stated and allow a new growth to develop. In the early fall of the 
first year a second cutting can be secured. After the first year the 
growth in the spring is more rapid and three harvests a year can be 
obtained. Harvesting can be accomplished by the use of a mowing- 
machine so adjusted as to cut the plants about 8 inches above the 
ground. The cut material can be raked up with a horserake run 
crosswise of the rows. 
In order to determine the proper stage and height at which the 
plants should be cut to produce the best yield and quality of oil, a 
number of tests were made, covering several years. In 1908 the 
plants were cut when they were 2 feet high. They were then tied 
in bundles, the bundles cut into three 8-inch lengths, and each portion 
distilled separately. The yield of oil obtained from each portion, 
together with the citral content of the oils, is shown in Table I. 
Table I. — Yield and citral content of lemon-grass oils distilled from plants 2 feet high. 
Portion of plant distilled. 
Yield of 
oil. 
Per cent. 
Upper third I 0. 46 
Middle third .24 
Lowest third .10 
Citral con- 
tent of the 
oil.i 
Per cent. 
70 
82 
i The citral content throughout all the experiments was determined by the sodium-sulphite method. 
From these results, which are borne out by additional data obtained 
in succeeding years, the conclusion is evident that close cutting will 
not be profitable, because of the low oil content in the lower portion 
of the plant. 
For the purpose of determiiiing whether the hauling cost could be 
reduced by drying the plants before taking them to the still, the 
following test was made: A quantity of fresh plants was collected, 
well mixed, and divided into three portions. The first portion was 
distilled green, the second portion was exposed to the sun for several 
hours until the blades were nearly dry, and the third portion was 
dried in a loft for several hours at 110° F. The two dried portions 
were then distilled separately and the yield of oil calculated on the 
original green weight of the material. The results secured, together 
with the citral content of the oils, are given in Table II. 
These results show that there was considerable loss of oil by drying 
the plants. In the case of the sun-dried plants the loss on a 4-ton 
crop would be 4.8 pounds of oil, or, at the prices prevailing for 1915, 
a loss of $3.84, which would more than pay for the extra hauling 
