Nigellia sativa L. plants were fertilized with different rates of NPK fertilizers and sprayed with the growth regulators BL-2142 at 0, 250, 500, and 1000 ppm, CCC at 0, 500, 1000, and 1500 ppm and Multiprop at 0. 12.5, 25, and 50 ppm.
The results indicated that both of NPK fertilization and growth regulator treatments enhanced the plant growth in terms of stem diameter, branch number and herb dry weight. Also, these treatments caused early flowering, increased fruit number and seed yield compared to the control plants.
The interaction between NPK fertilization and growth regulators had a synergistic effect. The highest seed yield was obtained when the plants received 200, 100, and 25 kg/feddan (feddan = 4200 sqm) of urea, calcium superphosphate and potassium sulphate, respectively and sprayed with CCC at 500 ppm.