Allelopathic Potential of Sorghum halepense Root Exudates on Germination and Seedling Growth of Wheat

Abstract

Allelopathic interactions between weeds and crops play a significant role in influencing seed germination, seedling establishment, and crop productivity in agricultural ecosystems. The present study evaluated the allelopathic potential of Sorghum halepense root exudates on the germination and early seedling growth of wheat under controlled laboratory conditions. Root exudates were collected from actively growing S. halepense plants and applied at different concentrations to wheat seeds to assess their inhibitory effects on germination and growth parameters. Observations were recorded on germination percentage, germination rate, root length, shoot length, seedling vigor index, and biomass accumulation. The results demonstrated that root exudates of S. halepense significantly suppressed wheat seed germination and seedling development in a concentration-dependent manner. Higher concentrations of root exudates caused substantial reductions in root elongation and shoot growth, indicating strong phytotoxic effects on wheat seedlings. Root growth was found to be more sensitive than shoot growth, suggesting direct interference of allelochemicals with cellular division and nutrient absorption processes. The inhibitory effects were attributed to the release of bioactive secondary metabolites from S. halepense roots that negatively affected physiological and metabolic activities in germinating seeds. The study highlights the ecological importance of allelopathy as a competitive mechanism contributing to the invasive and persistent nature of S. halepense in crop production systems. The findings provide valuable insights into weed–crop interactions and support the development of integrated weed management strategies aimed at minimizing the adverse effects of allelopathic weeds on wheat productivity.