The effect of salinity on germination, emergence, seed yield and biomass of black cumin

Abstract

Salinity sensitivity of black cumin (Nigella sativa L.) was studied to determine salinity effects on germination, emergence, biological yield, seed yield and plant height. A set of experiments were conducted under completely randomized design in the germinator, greenhouse and field. Seeds of black cumin were grown in a growth chamber irrigated with normal water, electric conductivity (EC) of 0.3 dS m-1 as the control, and treatments amended with NaCl to obtain EC from 3 to 39 dS m-1. Different EC treatments (3-39 dS m-1, 3-15 dS m-1 and 3-9 dS m-1) were applied at different phenological stages of germination, emerging and seed setting, respectively. The effect of salinity on seed germination, germination rate, shoot length, root length, seedling weight, root to shoot ratio and seed vigor was significant at p<0.01. The highest germination rate (94.8%) was observed at the salinity of 3 dS m-1 and no germination was observed at the salinity of 36 dS m-1. Increase of salinity from 0.3 (control) up to 15 dS m-1 significantly (p<0.01) influenced the rate and percentage of emergence. The highest germination percentage (52.5%) and emergence rate (9.2 seedlings per day) were achieved in the control treatment. Seed yield, biomass and plant height were affected significantly (p<0.05) by different salinity treatments. The essential oil percentage was not significantly affected by salinity stress. With an increase in the salinity level from 0.3 to 9 dS m-1, the average seed yield and biological yield were decreased from 105.5 to 40.2 g m-2 and from 550.2 to 268.6 g m-2 respectively.

Keywords

• Nigella sativa
• salinity
• growth stages
• seed yield