Background:

Dalea bicolor grows in the Chihuahuan Desert. It is an important fodder source for cattle and fauna, and its recommended for bioremediation and ecological restoration. This is the first study about its essential oil.

Questions and / or hypotheses:

How much essential oil produces D. bicolor at the end of flowering stage? Is the oil production equal under different environmental conditions? What climate and soil variables influence oil production? What compounds are found in the essential oil?

Species under study:

Dalea bicolor.

Study site and dates:

Four regions in the state of Chihuahua, within the latitudes of 26° 34’ 12” N and 28° 47’ 24” N. The sampling was carried out during November of 2017.

Methods:

Extraction of the essential oil by hydrodistillation. Analysis of variance of essential oil production among the regions. Correlation analysis between oil production and climate, as well as soil variables. Gas-mass chromatography coupled with mass spectrometry for the determination of the most likely essential oil compounds.

Results:

Essential oil production was different among the regions. In Aldama region it was significantly higher with 5.18 ± 0.64 g Kg-1 of dry matter. Essential oil production was correlated positively with air temperature and the concentration of boron and zinc in the soil. Seventeen compounds were detected in the essential oil.

Conclusions:

High air temperatures and soils rich in boron and zinc favor the production of D. bicolor essential oil. The main compound of the essential oil was 3-carene, followed by limonene, ocimene and β-phellandrene.