Essential oil yield and compositions of Dracocephalum moldavica L. in intercropping with fenugreek, inoculation with mycorrhizal fungi and bacteria

Abstract

Intercropping is one of the most important components of sustainable agriculture. The effects of chemical fertilizer (CF), arbuscular mycorrhizal fungi (AMF) (Glomus sp.) and AMF + nitrogen-fixing bacteria (NFB) including Azospirillum and Azotobacter (AMF + NFB) was studied on essential oil yield and compositions of Moldavian balm (Mb) (Dracocephalum moldavica L.) in sole cropping and intercropping with fenugreek (F) (Trigonella foenum-graecum L.). The experiment was conducted during 2020 and 2021 growing seasons in East Azarbayhan, Iran. The highest dry herbage yield (6132 kg ha−1) was obtained in Mb:F(4:2) and CF treatment. After sole Moldavian balm, the highest essential oil yield (15.28 kg ha−1) was obtained in Mb:F (4:2) and AMF + NFB treatment. Geranial, geranyl acetate, geraniol, neral, and nerol were the main chemical constituents of essential oil. In AMF + NFB treatments the geranial contents in intercropping patterns of Mb:F (1:1), (2:2) and (100:50), increased by 25.1, 15.5 and 34.6% compared with sole Moldavian balm. The highest LERT values were observed in Mb:F (100:50) cropping pattern in 2021 (1.70 and 1.63 for CF and AMF + NFB treatments). Generally, it can be concluded that Mb:F (100:50) intercropping and use of AMF + NFB bio-fertilizer could be recommended to medicinal plant growers in sustainable production systems.

Enhancing cotton sustainability: Multi-factorial intercropping, irrigation, and weed effects on productivity, quality and physiology

“…This increase in plant height can be attributed to competition for more light interception and limited light penetration through the canopy, as well as a lack of decomposition of auxin hormone under these intercropping conditions. Furthermore, a recent study by Amiriyan Chelan et al [ 30 ] focused on intercropping Dracocephalum moldavica L. with fenugreek ( Trigonella foenum-graecum L.). The researchers observed that the height of both species increased in the intercropping system compared to mono cropping.…”

“…The analysis of LER values revealed that the weedy plots exhibited the highest values, indicating a greater efficiency in land utilization within those particular conditions. Previous research has consistently demonstrated that the superiority of intercropping can be attributed to various factors, including distinct morphological properties and growth patterns, as well as the inherent ability of intercropping components to efficiently utilize vital resources such as soil, moisture, light, and essential nutrient elements [ 30 , 37 , 38 ]. Wang et al [ 38 ], reported that a jujube–cotton intercropping system had advantages in LER, yield, and income.…”