Comparative allelopathic impacts of leaf and flower water-based aqueous extracts of Lantana camara on Glycine max (L.) Merr. (soybean) crop

Invasive alien plants are proliferating due to global climate change often through mechanism called allelopathy, influencing other plants by releasing chemicals. This study examined the allelopathic impact of aqueous extracts of leaf (VPE) and flower (FPE) of Lantana camara L. on performance traits such as germination rate (GR), germination percentage (GP), total plant biomasses (TPB), total plant height (TPH), relative growth rate (RGR), stem volume (SV); plant level traits such as leaf weight ratio (LWR), stem weight ratio (SWR), root weight ratio (RWR), leaf area ratio (LAR), root shoot ratio (RS); leaf level traits such as leaf area (LA), single leaf area (SLA), single leaf weight (SLW), relative moisture content (RMC), seed vigor index (SVI) and productivity such as seed number (SN), reproductive index (REI), reproductive effort (RE) of native legume crop Glycine max (L.) Merr. (soybean). The pot experiment was performed in the glasshouse at the Department of Botany, D.S.B. Campus, Kumaun University, Nainital, using a completely randomized block design (CRBD) consisting of two components (leaf and flower) with four concentrations of aqueous extract (w/v): C₁ (25 g), C₂ (50 g), C₃ (75 g), C₄ (100 g) and one control, each replicated five times. The current findings showed that the VPE and FPE notably suppressed the germination, seedling growth and productivity of soybean and the effect was more pronounced for leaves. The highest concentration of VPE depicted percentage inhibition of 30–50% in performance trait biomass and 15–55% in productivity of soybean as compared to FPE. The results of aqueous extract effect with respect to infrared spectral analysis (FTIR) suggested that different functional groups of allelochemicals present in leaves and flowers of L. camara were extracted in water and may interfere with early seedling development of selected crop in agroecosystem. However, further studies have to be conducted for identification and characterization of phytochemicals by which one can understand their particular role in germination, seedling growth and yield. As a consequence, more research has to be done to demonstrate the allelopathic effect of L. camara on agronomic crops and to explore its use as a practical bioherbicidal agent.