Effects of sowing date and chemical fertilizer on seed vigor and qualitative and quantitative characteristics of Lady's mantle (Lallemantia royleana Benth.)

In order to evaluate the effects of autumn and spring sowing date and different amount of nitrogen and phosphorus fertilizer on qualitative characteristics and seed germination of Lallemantia (Lallemantia royleana Benth.), a factorial experiment in a randomized complete block design (RCBD) with three replicates was conducted in Medicinal Plant Research Center of the Shahed University during 2013-2014. The factors were sowing date at two levels (autumn and spring) and chemical fertilizer at three levels (without fertilizer, half dose of fertilizer (23 kg/ha N 50.6 kg/ha P2O5) and full doze of fertilizer (46 kg/ha N 101.2 kg/ha P2O5). Results for analysis of variance showed that the effect of sowing date on percentage of mucilage, germination percentage, mean germination time and germination rate, Catalase activity during grain filling, percentage of nitrogen and phosphorus was significant however on seed vigor index (SVI-II) was not-significant. The effect of chemical fertilizers on all traits was significant. The interaction effect of sowing date and fertilizer was not significant on all traits except the Catalase activity, percentage of nitrogen and phosphorus. Mean comparison showed that the highest seed germination percentage (74.815) was related to the autumn sowing and full amount of fertilizer (88.611). Regarding to the sowing date, the highest percentage of germination was related to the fall sowing (74.81) and regarding to fertilizer application, the full amount of fertilizer had the highest germination percentage (88.81). The highest catalase activity was 28 days after flowering in the autumn sowing and control (0.0075), and the lowest catalase activity was 7 days after flowering in spring planting and full dose of fertilizer (0.0014). For high germination indices, fertilizer and fall planting is recommended. Generally, results showed that fall sowing date and full dose of chemical fertilizer (46 kg/ha N and 101.2 kg/ha P2O5) produced seeds with higher seed vigor compared to other treatments.