Impact of inorganic fertilizer doses on growth, yield, physical and chemical components of broccoli plants
Nyan Tahir Mohammed, Hawar Sleman Halshoy, Naz Fayaq Saed, Hanan Abou Ali, Nask Ibrahim Mohammed, Sawsan Mohammed Ali
Abstract
Due to its high nutritional value and secondary metabolites, broccoli is one of the most significant vegetable crops globally. Thus, a greenhouse experiment was conducted to determine how the application of inorganic fertilizer impacts the plant growth and internal quality of broccoli plants. NPK fertilizer was applied at different levels (0, 300, 500, and 700 kg ha-1) three times at 14-day intervals after 21 days of transplanting. Results showed that 700 kg ha-1 NPK significantly improved some morphological characteristics, yield components, and total polyphenolic content (TPC) (93.89 μg GAE g-1 FW). 500 kg ha-1 provided the best value for leaf chlorophyll intensity (82.96 SPAD), TSS (11.57 ˚Brix), ascorbic acid (107.33 mg 100g-1 FW), and the highest rate of nitrate accumulation (502.33 ppm). Moreover, 300 kg ha-1 NPK produced the maximum results for leaf dry matter (20.27%), lateral head weight (354.33 g), zinc (551.58 ppm), manganese (11.29 ppm), and iron (41.17 ppm). Conversely, the control plants recorded the minimum results in this study except for total antioxidant activity (TAA) (70.50%) and copper (7.05 ppm). The results of this research could assist growers in determining the optimal amounts of NPK application for their broccoli plants or other crops while maintaining quality in greenhouses