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

Abstract

Two independent field experiments were carried out to investigate the influence of (i) three irrigation treatments (ID0 = 1585 m3 ha-1 , considered as a control; ID1 = 1015 m3 ha-1 ; and ID2 = 2180 m3 ha-1 ) and (ii) three plant density treatments (PD0 = 5.56 plants m-2 , considered as a control; PD1 = 4.44 plants m-2 ; and PD2 = 7.41 plants m-2 ) on the production, volatile composition of essential oil, and sensory quality of dill. 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. 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.