Relative water content, cell membrane stability, essential oil and morphology of Dracocphalum moldavica are influenced by drought stress and manure

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, Jiroft branch, in 2009. It was a split plot experimentbased on Randomized Completely 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 results showed that the effect of water deficit stress was significant on relative water content at 5% level and on cell membrane stability at 1% level. Water stress significantly decreased relative water content from 77.69% under mild stress under severe stress. Relative water content increased as manure level increased. 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.

Dragonhead, Drought Stress, essential oil content, Manure, yield