Effects of Different Nitrogen and Phosphorus Doses on the Growth, Yield and Yield Components of Black Cumin (Nigella sativa L.)

Abstract

ABSTRACT Proper adjustment of fertilizer dosage is necessary to achieve maximum yield. The use of too little or too much fertilizer can negatively affect plant growth. Nitrogen and phosphorus are two important nutrients in plant nutrition. Research on the combined effect of nitrogen and phosphorus on black cumin is very limited. Therefore, a field study was conducted to determine the effects of different nitrogen and phosphorus doses on the growth, yield and yield components of black cumin (Nigella sativa L.) under Mediterranean conditions during two growing seasons. Five doses (0 kg ha−1or control, 30 kg ha−1, 60 kg ha−1, 90 kg ha−1 and 120 kg ha−1) of nitrogen and four phosphorus doses (0 kg ha−1 or control, 20 kg ha−1, 40 kg ha−1 and 60 kg ha−1) were used as experimental factors. All the parameters except for capsule number were significantly affected by the growing season. Nitrogen dose significantly affected all the examined features except for seed number in capsule, seed weight in capsule and harvest index, while phosphorus dose significantly affected only SY and HI. In general, in the 2021–2022 growing season, black cumin had lower growth, yield and related traits. On the other hand, even though nitrogen fertilization, particularly at 90 kg ha−1 and 120 kg ha−1, had a positive effect on the yield and yield components of black cumin, the optimal nitrogen dose was 90 kg ha−1 for fewer input costs according to the results obtained from the present study. A phosphorus dose of 60 kg ha−1 was determined to be the appropriate dose in terms of seed yield, and this dose can be suggested for maximum seed yield of black cumin.