AbstractWe investigated the effect of foliar application of three levels of citric acid (0, 1000, and 3000 mg l-1) and three levels of malic acid (0, 1000, and 3000 mg l-1) on essential oil composition of dill. The experiment was conducted in a randomized design factorial arrangement (3 × 3), with four replications. The treatments were applied in three consecutive sprays starting from 24 days after emergence of seedlings and repeated every 10 days. The statistical analysis (path analysis) proved significant correlations among the applied factors and some constituents of essential oil. Citric acid caused decrease in some compounds including dillapiole and carvacrol and increased α-phellandrene, which was increased by malic acid, as well. Some compounds were even disappeared by some combinations. β-phellandrene was 9.6 % and 6.7 % in two treatments which contained only malic acid (3000 and 1000 mg l-1 respectively) while the remainder of treatments lacked β-phellandrene at all. While previous work has shown that these agents increase essential oil yield of basil and dill, our results suggest that they could be regarded as promising tools in manipulation of essential oil components of medicinal plants.