Effects of sowing date, nitrogen and phosphorus on grain yield, mucilage production, and nitrogen and phosphorus efficiency in Lallemantia royleana Benth.

In order to study the effect of sowing date and different amounts of nitrogen and phosphorus fertilizers on the grain yield, mucilage production, nitrogen and phosphorus uptake, utilization and use efficiency in Lallemantia royleana Benth., a factorial experiment was conducted in a randomized complete block design with three replications in medicinal plants research center  of Shahed University. The treatments included two levels of sowing date (autumn planting in the second week of November (2013) and spring planting in the second week of March (2014)) and three levels of nitrogen and phosphorus (control (without fertilizer), 50%: Npure 23 kg ha-1 + P2O5 50.6 kg ha-1 and 100%: Npure 46 kg ha-1 + P2O5 101.2 kg ha-1). The results showed that the interaction between sowing date and fertilizer application was significant on grain yield, mucilage production, and nitrogen and phosphorus uptake, utilization and use efficiency. At 50% fertilizer in both sowing dates, the amount of grain yield and mucilage production was obtained 377.15 kg ha-1 and 23.45%, respectively. The highest nitrogen utilization and use (respectively, 33.86 and 5 kg kg-1 at 50% fertilizer) and uptake efficiency (0.13 kg kg-1 at 100% fertilizer) were obtained in autumn planting. The highest phosphorus uptake and utilization efficiency (respectively, 0.06 and 11 kg kg1) was observed at 50% fertilizer in spring planting. The results showed the importance of nitrogen in Lallemantia royleana production in both sowing dates.