Impact of cultivation methods on properties of black cumin (Nigella sativa L.) seeds

The aim of this study was to determine the physical properties of black cumin seeds subjected to various cultivation methods (n=10) (level of nitrogen fertilization, sowing date, row spacing and integrated protection). The experiments were carried out in two years. Thousand seed weight ranged from 2.11 to 2.44 g in the first year, and from 1.96 to 2.39 g in the second year. In the first year, bulk density ranged from 0.464 to 0.506 g*cm(-3), true density - from 0.956 to 1.017 g*cm(-3), and porosity - from 49.6 to 53.9%. In the second year, bulk density ranged from 0.441 to 0.465 g*cm(-3), true density - from 0.996 to 1.061 g*cm(-3), and porosity - from 54.3 to 58.4%. The mean values of optical properties were also determined. In seeds harvested in the first year, the values of parameter L* reached 33.04-33.56, a*: 0.42-0.76, b*: 1-1.69, and YI E313: 5.61-7.91. In seeds harvested in the second year, the respective values were as follows: L*: 32.84-33.93, a*: 0.39-0.97, b*: 0.82-2.06, and YI E313: 5.22-9.78. In the first year, seed length (L) was in the range of 2.61-2.73 mm, width (S): 1.67-1.72 mm, mean thickness factor (W-5): 0.805-0.858, and roundness (W-13): 0.792-0.815. In seeds harvested in the second year, the respective values were as follows: L: 2.59-2.95 mm, S: 1.57-1.66 mm, W-5: 0.667-0.742, W-13: 0.825-0.871. The most beneficial influence on the physical parameters of black cumin seeds had nitrogen fertilization at 100 kg*ha(-1), seeding delayed by 20 days, row spacing of 15 or 30 cm, and the application of Penncozeb 80 WP.