Andriyana Setyawati 1,2,*, Anni Faridah 3, I Ketut Budaraga 4, Daimon Syukri 5, Nanda Saskya 1,2 and Lintang Wahyu Wijati 1
1Department of Agrotechnology, Faculty of Agriculture, Universitas Sebelas Maret, Surakarta, Indonesia; 2Department of Agronomy, Faculty of Agriculture, Universitas Sebelas Maret, Surakarta, Indonesia; 3Department of Tourism, Faculty of Tourism and Hospitality, Universitas Negeri Padang, Padang, Indonesia; 4Department of Agricultural Product Technology, Faculty of Agriculture, Universitas Ekasakti, Padang, Indonesia; 5Department of Food and Agriculture Product Technology, Faculty of Agricultural Technology, Universitas Andalas, Padang, Indonesia
*Corresponding author: andriyanasetyawati@staff.uns.ac.id
Salicylic acid (SA) and arbuscular mycorrhizal fungi (AMF) are potential approaches for improving the growth and essential oil production of citronella grass (Cymbopogon nardus L.). This study evaluated the interactive effects of salicylic acid (SA) and arbuscular mycorrhizal fungi (AMF) on citronella growth, physiological traits, and essential oil production using a 4 × 4 factorial Completely Randomized Design with four AMF doses (0, 20, 30, and 40 g plant⁻¹), four SA concentrations (0, 100, 150, and 200 mg L⁻¹), four replicates, and a total of 64 experimental units. Data were analyzed using analysis of variance (ANOVA), and treatment means were compared using Duncan's Multiple Range Test (DMRT) at α = 0.05. The interaction between AMF and SA was associated with increased vegetative growth, particularly leaf number. AMF significantly increased shoot fresh and dry weights, with the highest mean values of 145.94 and 34.93 g plant⁻¹, respectively, at 40 g plant⁻¹ AMF. Essential oil yield varied among treatment combinations, with the highest observed yield of 0.105 g plant⁻¹ (4.20 kg ha⁻¹) obtained with 200 mg L⁻¹ SA combined with 30 g plant⁻¹ AMF. The highest numerical oil content (0.072%) was recorded at 100 mg L⁻¹ SA without AMF. Essential oil yield was strongly and positively correlated with oil content (r = 0.884, P<0.001). GC–MS analysis showed that citronellal, citronellol, and geraniol were the predominant constituents, and the selected combined treatment showed a different relative composition than the untreated control. Mycorrhizal colonization reached 55% under the combination of 30 g plant⁻¹ AMF and 150 mg L⁻¹ SA. The combined application of AMF and SA improved biomass production, physiological performance, and essential oil characteristics, indicating its potential to enhance citronella productivity.