tFrench tarragon (Artemisia dracunculus L.) is a perennial herb in the family Asteraceae that is widelycultivated throughout the word. In order to study the effect of foliar application of Ca(NO3)2and KNO3on vegetative traits, essential oil yield, content and composition, a field experiment was conducted.Treatments including four levels of Ca(NO3)2and KNO3fertilizers (0, 1.5, 3, and 6 g/l) were set up in afactorial experiment based on Randomized Completely Block Design with three replications. The resultsshowed that Ca(NO3)2application significantly affected all tarragon vegetative traits, but had no signifi-cant effect on essential oil content. Furthermore, essential oil yield increased with Ca(NO3)2treatmentsby an average of 64.4% compared to the control. Ca(NO3)2fertilization increased leaf K and Ca contents.The gradual increase of Ca(NO3)2rates decreased estragole by 18.6%. On the other hand, KNO3fertiliza-tion significantly increased all of plant growth characters, leaf K and Ca contents. Foliar KNO3applicationsignificantly increased essential oil content and the yield by an average of 42.5% and 119.6%, respectively.The lowest content percentage of estragole (76.83%) is obtained from 1.5 g/l KNO3decreased by 0.6% anaverage when compared to the control. The interactive application of Ca(NO3)2and KNO3significantlyaffected the number of branch/plant, leaf K content and all of the essential oil constituents. Interactivetreatment of Ca(NO3)2and KNO3decreased estragole content by an average of 12.9%. In general, it can beconcluded that foliar application of Ca(NO3)2and KNO3can considerably improve the productivity traits,essential oil content, yield and composition of tarragon plant.

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