SPECIFIC COMPOSITION OF WEEDS AND THEM BIOLOGICAL GROUPS IN SHOT TERM CROP ROTATIONS OF SOUTH STEPPE OF UKRAINE

It is set on results research, that in the shot term crop rotations of South Steppe of Ukraine found out forty types of weeds, that to seventeen botanical families of plants belong. It is found out, that in middle for years researches in the structure of impurity of sowing of winter wheat weeds of dicotyledons occupied 85% from the general amount of weeds, monocotyledonous – 15%. Certainly, that the basic biological features of weeds was a high seminal yield, of long duration maintenance of viability of seed in soil and powerful rootage that got to earth on a considerable depth. Having a powerful rootage, weeds used moisture not only from the epiphases of soil but also from deeper. It is discovered that for diminishing to impurity in sowing of agricultural cultures important is combination of application of scientifically reasonable crop rotations, effective herbicides and till of soil.