Abstract

Ocimum tenuiflorum L. have been tested and demonstrated to have very effective antibacterial, antiviral, antifungal, antiinflammatory and painrelieving properties. The effects of accession and spacing on the growth, development, and essential oil yield and quality of Ocimum tenuiflorum L. in Vietnam were evaluated from 2019 to 2021. The experiment followed a randomized complete block design with five accessions (V0: Hanoi, Ha Nam, V2: Lao Cai, V3: Binh Dinh, and V4: Dak Lak) and three spacings (S1: 40 x 40 cm, S2: 40 x 50 cm, and S3: 40 x 60 cm). All trials were performed twice with three replicates per treatment. A remarkable variability in the effects of accession and spacing on essential oil yield and yield components were observed. The highest dried biomass was recorded in the V^ (8.08 t/ha) and V1S0 (7.76 t/ha) treatments, whereas the lowest dried biomass was recorded in the V4S2 treatment (5.19 t/ha). The highest essential oil content was recorded in the V^ and V:S2 treatments (1.19%), and the highest essential oil yield was recorded in the V^ treatment (74.17 kg/ha). Therefore, accessions from HaNam cultivated at the spacing of 40 x 50 cm were selected as the best accessions and spacing. Further studies at various locations and across different seasons will give better recommendations for optimal localities.