Impact of shade net intensities on herb, essential oil yield and quality in holy basil, Ocimum tenuiflorum L. elite germplasm INGR18044

Abstract

Ocimum species reveal a huge variation in growth, biomass production, oil composition and yield based on different growing conditions including light intensities. Therefore, here, we analyzed the light requirement of tulsi in the nontraditional area to harvest the maximum quantity of leaf and essential oil yield. An elite germplasm ‘INGR18044 (DOS-1)’ was evaluated for its quantitative and qualitative traits under green coloured shade-net of different light intensities. The fresh leaf yield, stem weight, root weight, root length, root diameter, dry leaf yield and essential oil yield from fresh leaves were found highest under control conditions. Sole crop compared with intercrop in agroforestry module, intercrop in fruit crop module and crop under shade-net (50%) conditions were compared and significantly higher yield was observed in control. However, the sole crop resulted in small sized leaves with early maturity. The total chlorophyll and carotenoid content were maximum in 90% shade-net intensity and minimum in control conditions; while, Methyl eugenol was maximum in control and it was found minimum under 90% shade-net intensity. The fresh leaf yield, seed yield, essential oil yield, number of PGs per unit leaf area and methyl eugenol (ME) content showed a negative relationship and leaf area, total chlorophyll and carotenoid content showed a positive relationship with increased shade-net intensities. The poor leaf yield and oil yield were observed under different SNIs(Shade Net Intensities) but large-sized leaves stayed green and a continuous supply of fresh leaves was made possible under shade conditions and as an intercrop crop.