Abstract
Decreased wheat crop yields due to the presence of weeds, insufficiently effective herbicides, and the development of weed resistance to high-efficiency herbicides indicated the need to develop alternative ways to control weeds. Therefore, we sought a possible solution in examining the efficiency of different concentrations (1, 5, 10 and 20%) of aqueous extracts of Ambrosia artemisiifolia and Sorghum halepense in controlling certain weed species for wheat crops: Avena fatua, Bromus rigidus and Convolvulus arvensis. The efficacy of aqueous extracts through the content of total phenols and four polyphenolic acids (chlorogenic, p-coumaric, and sikimic) on the level of shikimic acid concentration in treated weeds was investigated. Statistical analysis of the data showed that the change all tested concentrations of aqueous extracts affect the change in the concentrations of sikimic acid , especially the 20% solution of A. artemisiifolia. Conducted research also showed that method of monitoring the content of shikimic acid is adequate for determining the herbicidal effect of plant aqueous extracts