Irrigation dose and plant density affect the volatile composition and sensory quality of dill (Anethum graveolens L.).

Background: Two independent field experiments were carried out to investigate the influence of (i) three irrigation treatments (ID0 = 1585 m ha , considered as a control; ID1 = 1015 m ha ; and ID2 = 2180 m ha ) and (ii) three plant density treatments (PD0 = 5.56 plants m , considered as a control; PD1 = 4.44 plants m ; and PD2 = 7.41 plants m ) on the production, volatile composition of essential oil, and sensory quality of dill.

Results: The highest plant yield was obtained with intermediate conditions of both irrigation dose (ID0) and plant density (PD0). The main compounds of the essential oil were α-phellandrene, dill ether and β-phellandrene. The highest irrigation dose (ID2) produced the highest concentrations of most of the main compounds: α-phellandrene (49.5 mg per 100 g), β-phellandrene (6.89 mg per 100 g) and limonene (2.49 mg per 100 g). A similar pattern was found for the highest plant density (PD2): α-phellandrene (71.0 mg per 100 g), dill ether (16.7 mg per 100 g) and β-phellandrene (9.70 mg per 100 g). The use of descriptive sensory analysis helped in reaching a final decision, and the dill plants with the highest sensory quality were those of the ID2 and PD0 treatments.

Conclusion: The final recommendation is to use the irrigation dose ID2 and the plant density PD2 if the objective is to produce dill samples with the highest aromatic and sensory quality; however, if the only objective is to produce high amounts of dill, the best options are ID0 and PD0. © 2016 Society of Chemical Industry.