Organic cultivation of Plantago ovata and Plantago psyllium in response to water stress

In order to investigate the response of two species of P. ovata and P. psyllium to water deficit and manure, an experiment was conducted at the Agricultural Research Station, Ferdowsi University of Mashhad, in April 2002. For this purpose a split-factorial experiment based on completely randomized block design with three replications was used. Three irrigation intervals (every 10, 20 and 30 days) allocated in the main plots and three levels of animal manure (5, 10 and 15 tons/ha) and two species of plantago in factorial arrangement were as sub plots. Criteria such as plant height, spike length, number of spikes per plant, number of seeds per spike, 1000-seed weight, straw and seed yield were measured accordingly. Three quality characters namely amount of mucilage, swelling factor and swelling rate per gram mucilage were also measured. The results indicated that spike length and seed yield were significantly affected by irrigation intervals. The highest seed yield in P. ovata and P. psyllium was obtained in irrigation intervals of 20 and 10 days, respectively. There was no significant effect on another criteria by irrigation intervals. Effect of animal manure was only significant on seed yield. Seed yield was higher with application of 5 tons/ha and 15 tons/ha in P. ovata and P. psyllium, respectively. There was no significant correlation between the amount of mucilage, swelling factor and 1000-seed weight. However, the highest amount of mucilage were obtained in irrigation intervals of 30 and 10 days in P. ovata and P. psyllium respectively, maximum swelling factor with irrigation in 30 days interval and the highest swelling rate per gram mucilage in P. ovata and P. psyllium by irrigation intervals of 20 and 10 days, respectively. In water deficit condition and low-input agricultural systems it seems that P. ovata is more resistant species compared with P. psyllium