The interaction impact of compost and biostimulants on growth, yield and oil content of black cumin (Nigella sativa L.) plants.

This study was conducted during the seasons 2020/2021 and 2021/2022 to investigate the effect of the interaction between compost and biostimulants on growth measurements, seed yield, and oil production of black cumin (Nigella sativa L.). Four levels of fertilizer (0.6, 12, 18 tons/ha) were used. While the biostimulants were ascorbic acid (AS) at 100 ppm, yeast extract (YE) at 8 g/L, and AS at 100 ppm + 8 g/L YE. The plants were treated with these stimuli as follows: control (without addition), 100 ppm, YE at 8 g/L, and the results showed that fertilization at all levels, as well as foliar spraying with the used stimuli, led to a significant increase. Growth parameters, number of capsules, seed production, as well as fixed and volatile oil production, and plant treatment with organic fertilizers at a high level (18 tons). /ha) recorded the highest values for the trait under study. It was also shown that the foliar treatment at a concentration of 8 g/l YE was more effective in increasing the previously studied variables. All interactions were great. Most of the composite coefficients increased significantly for all the traits studied. Moreover, the application of manure at a high rate (18 t/ha) at a rate of 8 g/l YE was the best treatment. GC-MS analysis of the volatile and persistent oil showed that the main constituents of both species were also affected by the use of organic fertilizers and biotreatments. The combination of high-rate fertilizer (18 t/ha) plus AS at 100 ppm + 8 g/L YE improved main oil components compared to untreated plants.