The investigation of vermicompost organic fertilizer on some of physiological and qualitative traits of different varieties of Calendula officinalis L.under different levels of drought stress

Since medicinal plants in natural areas spread within the broad geographic limitations and collection and access to them is not cost-effective and on other hand, the use of natural habitats will not be enough for the pharmacy industry, therefore, it is necessary to grow these plants in agricultural areas. In this regard, the choice of the landraces and suitable cultivars and nutrition and irrigation management, play an important role in increasing the quantity and quality of medicinal plants and reduce the negative effects of various environmental stresses on plants. The present research aimed to study the effect of drought stress on some physiological and quality traits of calendula varieties under use and non use of vermicompost. In order to investigate of the effect of vermicompost levels on some of physiological and qualitative traits of different varieties of calendula (Calendula officinalis L.) under different drought stress levels, a pot experiment was conducted as split factorial based on a randomized complete block design with four replications in Torbat- Heydariyeh during 2012-2013. Treatments included vermicompost in two levels (0 and 50 valium percentage; the half volume of pot was soil and half volume, vermicompost) and drought stress in three levels (100, 50 and 20 percentage of field capacity) in main plots and seven varieties (low petals and many petals of Tehran and Esfahan as Iranian varieties and Faron, Golden yellow و Dandy as Netherland varieties) in sub plots. For applying water stress, after determining field capacity of soil, water loss per day was provided by weight method. Meatured traits included total dry weight, flower, leaf, stem and root dry weight, essential oil percentage and flower’s extract. The result indicated that with vermicompost applying, total physiological traits and essential oil percentage of calendula were increased. With increasing in drought stress to 25 percentage of field capacity, stem, root, leaf and flower dry weights decreased 36. 5, 43. 8, 37. 9, 45. 2 percentage compared to irrgation in field capacity, respectively. With increasing drought stress to 25 percentage of field capacity, essential oil percentage of calendula was decreased (39. 1%). Different varieties were different for root to shoot dry weight ratio and harvest index. The highest flower dry weight was obtained in Golden yellow variety that it had n’t significant difference with many petals of Esfahan and Tehran. The highest essential oil percentage was observed in low petals and many petals of Esfahan, many petals of Tehran and Golden yellow. The intraction effect of vermicompost, drought stress and variety was significant on total dry weight of plant, stem, flower and root to shoot dry weight, statistically. The hieghst total, leaf, stem, root and flower dry weight were observed in Foren variety under field capacity and fertilizer appling. Generally, the study results showed that the reaction of varieties to drought stress levels and nutritional condition was different, but optimum nutritional status could improve the growth and yield of calendula varieties and also adjust the effects of drought.