Adaptation strategies for cumin in Sabzevar, Iran: planting date and irrigation management

Abstract

The current study aimed to investigate the effect of planting date and irrigation on some characteristics of cumin cultivated in Iran. The experimental characteristics included three planting dates and five irrigation regimes. Irrigation at flowering + seed filling stage and full irrigation had the highest essential oil content (3.6%) and plant height (16.71 cm), respectively. On all planting dates, irrigation enhanced the total chlorophyll and carotenoids content, relative water content, umbel number plant−1, seed number umbel−1, 1,000-seed weight, and seed yield but reduced the proline content and water-use efficiency (WUE). The highest chlorophyll content (1.54 mg g−1 fresh weight (FW)), carotenoids content (0.35 mg g−1 FW), umbel number plant−1 (18.03), seed number umbel−1 (21.16), 1,000-seed weight (4.12 g), seed yield (1002.7 kg ha−1), and essential oil yield (22.13 kg ha−1) were obtained on 19 January and irrigation at the flowering + seed filling stages. The greatest amount of WUE (0.53 kg m−3) was measured on 9 January under no irrigation condition. Therefore, to produce cumin under similar climatic conditions, early planting of cumin in early January, along with two irrigations at the flowering and seed filling stages, is recommended. HIGHLIGHTS Changing the plant growth conditions changes the morphological and physiological characteristics.; Delay in cumin planting reduced the carotenoids content.; By balancing redox reactions, proline induces cellular homeostasis and reduces lipid peroxidation.; The water deficit caused the remarkable accumulation of secondary metabolites.;

Keywords

• drought
• essential oil
• osmoprotectant
• proline