Effect of nitrogen and phosphorus on seed yield parameters of calendula (Calendula officinalis L.) var. Touch of Red Mixture

The experiment was conducted to investigate the effect of nitrogen and phosphorus levels on seed production of calendula. The number of seeds per flower head, number of seeds per plant, seed yield and seed test weight increased significantly as the quantity of nitrogen was increased from 0 to 150 kg/ha. The highest yield was recorded by 150 kg nitrogen and 80 kg phosphorus/ha. The interaction between nitrogen and phosphorus levels showed that maximum yield was recorded with 150 kg N/ha + 80 kg P/ha followed by 200 kg N/ha + 80 kg P/ha and least significant effect was shown in control. The treatments combination of 150 kg N/ha + 80 kg P/ha) also recorded highest C: B ratio and net returns.