Effects of drought stress and manure on dry herb yield and essential oil of dragonhead (Dracocphalum moldavica) in Jiroft erea.

In the current study, the effect of water deficit stress or drought on relative water content and cell membrane stability of dragonhead (Dracocepha lummoldavica) was studied in a greenhouse experiment carried out at Islamic Azad University, Jiroftbranch, in 2009. It was a split plot experimentbased on Randomized Complete Block Design with three replications, in which vertical factor included three levels of drought stress (irrigation when soil moisture reached 75% of field capacity [mild stress], irrigation when soil moisture reached 50% of field capacity [moderate stress] and irrigation when soil moisture reached 25% of field capacity [severe stress]). The highest dry yield of vegetative body in dracocephalum was obtained by mild stress as 4868.27kg/ha. The highest dry yield of vegetative body in dracocephalum as 5719.67kg/ha was obtained by application of 40 ton/ha of manure. considering essential oil content as the main goal of dracocephalum production and concerning the fact that oil yield as 13.10, 9.91, 9.91 and 9.91 kg/ha was achieved by interaction of the two factors in mild stress and 40ton/ha manure, mild stress and 30ton/ha, medium stress and 40ton/ha manure and medium stress and 30ton/ha manure, respectively; the medium drought stress together with application of 30tpn/ha is recommended for Jiroft region as the superior treatment which resulted in production of 9.91kg/ha essential oils.