The effect of different irrigation water levels on yield and yield characteristics of basil (Ocimum basilicum L.)

Objective: This study was carried out in 2022 as a trial in pot in order to research into the effects of different drip irrigation levels on yield and yield components as well as important ethereal oil parameters in the basil under the conditions prevailing in Aydın. Material and Methods: The random parcels of the research were established with three repetitions according to the pattern of the trial. In the study, 5 different irrigation levels (120%; 100%; 80%; 60% and 40%) were examined. The subjects of irrigation in the study consisted of 5 different irrigation water levels in which 40%, 60%, 80%, 100% and 120% of the amount of irrigation water required to bring the decreased level of moisture in 2 days in the pots to the pot water retention capacity was applied through drip irrigation method. Results: In the study, the amount of irrigation water applied to the subjects varied between 5.15-15.46 L/plant, while the plant water consumption values varied between 5.37-15.61 L/plant. Irrigation water levels in basil were found to be significant at the level of 1% (p<0.01) on both wet herb and dry herb yields. While the average green herb yields varied between 78-140 g/plant, the dry herb yields varied between 20.1-24 g/plant. In respect of the total water use efficiency values, the green herb WUE values varied between 8.57-14.52 g/L, and the dry herba WUE values varied between 1.53- 3.74 g/L. The different drip irrigation levels applied in the study were found effective on basil yield characteristics (plant height, plant diameter, number of plant branches) and oil quality characteristics (oil ratio, Limonene, Gamma-terpinene; Linalool; Linalyl acetate; Cymol and Germacrene-D) (p<0.01). Conclusion: In conclusion, I120 subject where wet herb and dry herb yields are high under conditions where irrigation water is sufficient and unit water cost is economical can be recommended. However, in conditions where irrigation water is limited and unit water cost is not economical, I40 subject that uses water more efficiently can be recommended.