Effect of Nitrogen and Phosphorus on the Growth and Seed Yield of Spinach

Abstract

The experiment was conducted at the farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during Rabi (November 2017 to March 2018) season to find out the growth, yield and economic benefit of spinach seed as influenced by nitrogen and phosphorus. The research involved two factors. Factor A: Four levels of nitrogen; N0= 0 kg/ha N1= 27.6 kg/ha, N2=55.2 kg/ha, N3= 82.8 kg/ha, and factor B: Four levels of phosphorus; P0= 0 kg/ha; P1 = 15.84 kg/ha, P2= 31.68 kg/ha, P3= 47.52 kg/ha. There were 16 treatment combinations in the experiment and laid out in Randomized Complete Block Design (RCBD) with three replications. Quality tests of seeds were done based on the germination test (%), seed vigor test (Electrical conductivity). In case of nitrogen, the highest seed yield (1.10 t ha-1), germination percentage (87.33%) and lowest value in EC test (11.87 dS/cm) were obtained from N2, while the lowest seed yield (0.81 t ha-1), germination percentage (79.33%) and highest value in EC test ( 13.87 dS/cm) from N0. For phosphorus levels, the highest seed yield (1.05 t ha-1), germination percentage (86.58 % and) and lowest value in EC test (11.79 dS/cm) were recorded from P2, whereas the lowest seed yield (0.84 t ha-1), germination percentage (79.91%) and highest value in EC test (13.35 dS/cm) from P0. Due to mutual effect, the highest seed yield (1.30 t ha-1), germination percentage (91.33%) and lowest value in EC test (10.2 dS/cm) were noted from N2P2, whereas the lowest seed yield (0.69 t ha-1), germination percentage (72.66%) and highest value in EC test (14.83 dS/cm) from N0P0. From the economic point of view, the highest Benefit-Cost Ratio (BCR) (1.59) was found in the treatment of N2P2 and the lowest BCR (1.01) was found in the treatment of N0P0. It is apparent that the treatment combination N2P2 gave the best performance for the seed yield and economic benefit of spinach.