Remeniuk S. Biological features and the development of control measures of silkweed (Asclepias syriaca L.) under the conditions of the left-bank Forest-steppe of Ukraine

The thesis is devoted to studying of features of biology and development of a malicious perennial weed of Asclepias syriaca L. under the conditions of the left-bank Forest-steppe of Ukraine and development of ways of its successful control on arable lands and in culture plantings. Phenological phases of development of Asclepias syriaca L. and their duration, feature of weed seed germination depending on concentration of various forms of nitrogen and level of acidity of solution were established. As a result of the carried-out broad search of herbicides and their tank compositions and optimization of the most sensitive phases of development of plant weeds to action of preparations it was developed and patented herbicidal composition Starane 250, emulsion concentrate +Raundap, aqueous solution (0,8+6,0 l/ha) that provides the successful control of perennial plants of Asclepias syriaca L. on arable lands. Annual plants of Asclepias syriaca L. in a phase cotyledons can successfully control in sugar beet crops the herbicides on the basis of active ingredients fenmedifam, desmedifam, etofumezata, in a consumption rate of 2,0 l/ha, in winter wheat crops active ingredient of fluroksypir in norm is 0,8 l/ha. Delay with carrying out sprayings of crops leads to increase of phase resistance of weed plants to effect of herbicides.