effects of salicylic acid and jasmonic acid on hill reaction and photosynthetic pigment (dracocephalum moldavica l.) in different levels of drought stress

objective: in order to study the effect of drought stress, salicylic acid (sa) and  jasmonic acid (ja) foliar application on hill reaction and photosynthetic pigments. methods:experiment was done as factorial on the basis of completely randomized design in 4 replications. irrigation in 3 levels (fc,   fc and  fc), salicylic acid in 2 levels (0 and 0.5 mm) and jasmonic acid in 2 levels (0 and 50 µm). results: the results indicated that, the effects drought stress, salicylic acid and jasmonic acid on hill reaction, chlorophyll a, chlorophyll b, chlorophyll a+b, β-carotene and xanthophyll were significant. drough stress increased the content of β-carotene (1.83  ) and xanthophyll (2.60 ). the 50 (µm) foliar application of jasmonate  and salicylic acid under normal irrigation condition gained to maximum amounts of hill reaction, chlorophyll a, chlorophyll b, chlorophyll a+b, β-carotene and xanthophyll.  according to the results, exogenous salicylic acid and jasmonic acid application can improve drought tolerance in moldavian dragonhead (dracocephalum moldavica l.).