2.2. Essential oil content
At the end of the vegetative cycle, the lemon grass plants were
harvested early in the morning (from 7:00 to 10:00 am) and then
separated into aerial and root portions.
The plants were obtained from all treatments and analyzed.
From each treatment, 100 g of the fresh aerial parts of the lemon
grass plants were submitted to hydrodistillation (with 1 L deionized
water)in a modified Clevenger apparatus. The distillation time
was 2 h. The EO was removed with hexane, filtered with anhydrous
Na2SO4 and stored in amber flasks at 4 ◦C (Santos et al., 2009). The
content (%) was obtained after the solvent evaporation.
2.3. Chemical identification of essential oil by GC/MS
The chemical identification ofthe EO was made by GC–MS, using
an Agilent 5973 Network Mass Selective Detector. The capillary column
was the DB-5 (5% phenyl–methylsiloxane, 30 m × 0.25 mm id,
0.25 m). The detection system was the electronic impact on the
“Split” mode 2:1 mL min−1. The column temperature was initially
programmed at 40 ◦C, heating at 8 ◦C min−1 to reach the final temperature
of 300 ◦C. The injector and detector temperatures were
250 ◦C and 320 ◦C, respectively. Helium was used as a carrier gas at
flow rate of 4.8 mL min−1. The amount of injected sample was 1 L.