INFLUENCE OF WATER DEFICIT ON SEED YIELD AND ESSENTIAL OIL CONTENT OF DILL (Anithum graveolens L.)

Anethum graveolens Linn. (Umbelliferae, A. graveolens) is a widely used spice with a long history of traditional medicinal use for the treatment of various ailments. The biosynthesis of secondary metabolites in medicinal and aromatic plants is affected by abiotic stresses such as water deficit. This study was carried out to evaluate seed yield and essential oil of dill under five irrigation disruption treatments at different growth stages. Four irrigation treatments were consisted of irrigation disruption during stem elongation (I1), irrigation disruption during umbel emergence and grain filling (I2), irrigation disruption during umbel emergence (I3), irrigation disruption during grain filling (I4) and well watered treatment (I5). Results showed that the different irrigation treatments had no considerable effect on grain yield of dill. The highest and lowest essential oil content was obtained under I1 and I5 treatments, respectively. It seems that the essential oil content of dill can be increased partly by a moderate water deficit during vegetative stage (stem elongation).