Tagetes minuta L. from the Asteraceae family is an annual perennial herb, important herbaceous aromatic essential oil plant species that grows wild from spring to early winter (Pandey et al., 2015). Pinching is the manual amputation of the growing tips of plants. The practice is managed commonly by preventing the influence of apical dominance, to promote the flourishing growth of the canopy (Kumar et al., 2014). Plant spacing is an effective factor in the quantity and quality of plant products that affect directly on plant growth and essential oil content. Therefore, a field experiment was conducted to study the effect of pinching and cultivation row spacing on biomass, essential oil content and composition of T. minuta. The treatments comprised of two pinchings (pinching and without pinching) and three row spacing (30, 40, and 50 cm). The findings of this experiment showed that the highest aboveground biomass, antioxidant activity, and essential oil content were observed in 50 cm row spacing with pinching. The oil analyses by GC and GC/MS resulted in the identification of 29 compounds representing 93.83-96.98% of the oil. The major constituents were dihydrotagetone (39.19%), β-ocimene (20.99%), tagetone (15.84%), limonene (7.04%), and (E)-ocimenone (6.32%). The highest percentage of each constituent were obtained in different treatment as following: dihydrotagetone in 40 cm row spacing without pinching, β-ocimene and limonene in 40 cm row spacing with pinching, tagetone and (E)-ocimenone in 50 cm row spacing without pinching. It can be concluded that essential oil content and composition are influenced by pinching and row spacing.

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