ABSTRACT
The genus Tagetes is a possible source of essential oils for the biorational control of pests and diseases in Mexico. The aim of the present study was to assess the distance between plants (PD; 15 × 80, 30 × 80 and 60 × 80 cm) and urea fertilization (0, 60 and 120 kg·he-1 N) for biomass production and essential oil in Tagetes terniflora HBK. Oil was obtained by the aerial part hydro-distillation and its chemical composition was analyzed by gas chromatography coupled to mass spectrometry. Factors N, PD and their interaction did not change plant height or the number of branches per plant; however, PD factor modified fresh tissue (FW) and dry tissue (DW) weights and the amount of oil per plant (p ≤ 0.05) which represent a good biomass production (30 to 72.5 ton·he-1 FW, 11 to 27 ton·he-1 DW) and oil producing (168 to 383 L·he-1 ) potential in the field. Urea did not have effect on both biomass and oil response per plant but interaction of 15 x 80 DP and 120 N could favor higher biomass and oil production potential (78 ton FW, 28 ton·he-1 DW and 608 L·he-1 , respectively). Essential oil yield varied from 0.3 to 2.1% according to the management conditions. A total of 11 major compounds were identified in essential oil, the relative quantity was constant in different agronomic management factors: E- tagetone (22%), cistagetenone (20.4%), transtagetenone (20.4%), dihydrotagetone (13.4%) and cis-β-ocimene (10.3%), trans-β-ocimene (5.0%), propenyl anisole (4.3%), sphatulenole (1.1%), allyl anisole (0.7%), Z-tagetone (0.5%) and limonene (0.5%).