Study on yield and seed quality of Plantago ovata Forssk., under different nitrogen treatments and deficit irrigation

In order to investigate the response of quantitative and qualitative characteristics of isabgol (Plantago ovata Forssk.) to different irrigation regimes and different fertilizers, a field experiment was conducted at the research farm, Shahrekord University, 2009. The experimental design was split-plot in randomized complete blocks design with three replications. Whole plots were three replications of irrigation intervals (irrigation after 7, 14 and 21 days), and sub plots were different N fertilizers including 100% chemical fertilizer, 100% chicken manure, 75% chemical fertilizer + 25% chicken manure, 50% chemical fertilizer + 50% chicken manure, 25% chemical fertilizer + 75% chicken manure and no fertilizer. The irrigation regimes showed significant effect on the plant seed yield, plant height, number of spike per plant, spike length and mucilage percentage, but was not affected significantly in number of tillers per plant, number of seeds per plant, 1000-seed weights and seed swelling. The greatest seed yield and mucilage percentage were obtained at 7 and 14 days of irrigation regimes respectively. Seed yield, number of tillers per plant, plant height, number of spikes per plant, spike length, number of seeds per plant, 1000-seed weights, mucilage percentage and seed swelling were significantly affected under different fertilizer treatments. The maximum dry weight and seed yield were obtained with 50% and 70% replacement of chemical fertilizer and chicken manure respectively. In summary, our results illustrated that application of 75% chicken manure + 25% chemical fertilizer with 14 days intervals of irrigation was beneficial to isabgol.