Effect of drought stress on yield, yield components and essential oil in coriander (Coriandrum sativum L.) under the influence of organic and inorganic fertilizers

In order to investigate the effect of drought stress and effect of organic and chemical fertilizers on morphological, agronomic of characters and the essential oil amount in coriander, a field experiment was arranged as split plot based on randomized complete block design in three replications at Agricultural Research Station, College of Agriculture, University of Torbat Heydarieh., Iran during growing season of 2010-2011. Treatments were consisted of three levels of drought stress (30, 60 and 90% FC) and fertilizer treatments (control, NPK (60: 60: 40), cow manure (25ton/hec) and vermicompost (25ton/hec). Different traits such as plant height, stem diameter, number of branches, number of leaves per plant, fresh and dry weight, hebage yield and number of umbels per plant, number of seeds per umbel, total number of seeds in plant, fruit yield, 1000 seed weight and essential oil percentage and yield were recorded. Analysis of variance indicated that water stress and application of fertilizer treatmenst had significant effect on all studied trait (p>0.01). The maximum hebage yield (5371 kg/ha) and seed yield (3905 kg/ha) were achieved in 90% FC combined with NPK and mild stress under NPK treatment, respectively. The highest essential oil percentage (0.77%) and essential oil yield (18.49 kg/ha) were obtained in mild stress by using chemical fertilizer. According to the fact that application of fertilizers in mild stress conditions leads to increase in essential oil's yield and percentage, hence the use of chemical fertilizers in coriander cultivation as a medicinal plant in mild drought stress would be recommendable.