Chemical Composition and Antibacterial Activity of Essential Oils of Tagetes minuta (Asteraceae) against Selected Plant Pathogenic Bacteria

Table 3

Minimum inhibitory concentrations and minimum bactericidal concentrations of essential oils of Tagetes minuta on three plant pathogenic bacteria.

Tube/plate number	EOs concentration (mg/mL) 10^2	⁢Growth of bacteria in MHB tubes			⁢Growth of bacteria in MHA plates
		XAP	XAM	PSP	XAP	XAM	PSP
#1	Crude EOs	−	−	−	−	−	−
#2	3.8	−	−	−	−	−	−
#3	1.9	−	−	−	−	−	−
#4	0.95	−	−	−	−	+	−
#5	0.48	−	−	−	+	+	+
#6	0.24	−	+	−	+	+	+
#7	0.12	+	+	+	+	+	+
#8	0.06	+	+	+	+	+	+
#9	0.03	+	+	+	+	+	+
#10	0.015	+	+	+	+	+	+
#11	−ve control	+	+	+	+	+	+
#13	+ve control	−	−	−	−	−	−

+: growth; −: no growth of the bacteria; and XAP: X. axonopodis pv. phaseoli, XAM: X. axonopodis pv. manihotis, and PSP: P. savastanoi pv. Phaseolicola.
MHB: Muller-Hinton broth; MHA: Muller-Hinton Agar; tube 1: bacterial inoculum and undiluted crude essential oils; tubes 2 to 10: MHB, bacterial inocula, and essential oils of different concentrations; tube 11: bacterial inoculum and MHB (−ve control); and tube 13: bacterial inoculum, MHB, and the standard bactericide (+ve control).