Effect of soil moisture on oil quality of rose-scented geranium (Pelargonium graveolens)

Abstract

To enhance the yield and quality of rose-scented geranium (Pelargonium graveolens) essential oil, an experiment was carried out in the subtropical conditions of North India. The crop was harvested under varying soil moisture levels (9.5-26.0%). The yield and essential oil composition of rose-scented geranium varied significantly with these moisture levels. The yield was notably higher under moderate soil moisture conditions (T4; 1.40 mL per plant) as compared to excessive moisture (T2; 1.11 mL per plant). The citronellol-to-geraniol (C/G) ratio, a key quality indicator of geranium oil, varied from 0.54 to 0.88 under different treatments, with the lowest ratios observed under higher moisture levels. In conclusion, soil moisture is crucial at harvest time. Both very low and excessive soil moisture negatively impacted the essential oil yield of rose-scented geranium.