Abstract

Weed control is a necessary tool in crop production because of remarkable economic losses in crop yield. A bioassay experiment was conducted in order to evaluate phytotoxic activity of Sorghum bicolor shoot water extract on germination and some parameters of Triticum aestivum L., Triticum durum L., Hordeum spontaneum, Avena fatua and Phalaris minor seeds. The concentration levels were (control, 15, 30, 45, 60%) in this study, shoot aqueous extract of Sorghum bicolor were applied to 20 seeds of each species in sterilized petri dishes during the 10 days incubated period at 22 °C and the experimental units were laid out in randomized complete design. The quantification and determination of allelopathic substances were done by using high performance liquid chromatography (HPLC). Results indicated that sorghum shoot aqueous extract significantly affected germination percentage, inhibition of germination percentage, total dry weight, seedling growth inhibition, plumule and radicle dry weight, seedling length, seedling vigor index, plumule and radicle length, plumule and radicle elongation velocity. Moreover the five tested plant species were responded significantly in different ratio to sorghum aqueous extracts. In addition, all concentration levels had on germination and all growth parameters especially higher concentration levels. The germination percentage of wild barley was eliminated due to apply 45 and 60% concentrations. The HPLC results showed that the shoot of sorghum plant contained syringic acid, vanillic acid and ferulic acid. The outcomes proposed that the sorghum shoot concentrates can be recommended as a bioherbicide to inhibit weed germination.