Name of bacteria Description Average of zone  inhibition (mm) ±SD   Degree of inhibition    Blue River Ellegance Purple  Staphylococcus aureus ATCC 25923* 21.8 ± 0.4 24.0 ± 0.2 BR  +++ EP  +++ Staphylococcus aureus  MRSA ** 25.0 ± 0.3 26.0 ± 0.6 +++ +++ Pseudomonas aeruginosa ATCC 9027 10.1 ± 0.2 8.0 ± 0.2 +/- +/- Pseudomonas aeruginosa PCR skin *** 8.9 ± 0.5 NZ +/- - Escherichia coli   ATCC 25922 12.5 ± 0.3 13.2 ± 0.4 + + Enterococcus faecalis   9.0 ± 0.2 10.5 ± 0.3 +/- +

*The S. aureus strain ATCC 25923 is a strain to control antibiograms, ** MRSA – Methicillin Resistant Staphylococcus aureus is a multi-antibiotic resistance strain, *** PCR – Polymerase Chain Reaction ; NZ= No zone inhibition of growth Relative degree of inhibition of bacterial growth: ≤ 6 mm (-) no zone inhibition of growth; 7-9 mm (+/-); 10-14 mm (+); 15-18 (++); ≥ 19 mm (+++)

Table 3: Zones of inhibition of bacterial growth by essential oils from the leafy stems of two lavender (Lavandula angustifolia) varieties and relative degree of inhibition of bacterial growth.