White lupine is one of the best forage crops. New varieties of lupin, that are created in recent years and listed in the National register of plant varieties of Ukraine, have a number of valuable traits that can give high and stable yield of seeds and green mass and thereby to ensure the needs of livestock high-quality, higher protein feed. Due to its biological characteristics, lupin is a crop that needs weeds clean areas. The determination of species composition of weeds and the effectiveness of herbicides for lupin crops still remains understudied and important issue.

The aim of the research was to study the level of infestation and species composition of weeds on white lupin crops and the effectiveness of various herbicides, depending on active substance, of the rate and timing of bringing herbicides.

The research was carried out in 2013-2015 in NSC "Institute of agriculture NAAS" in the fields of experimental farm "Chabany" (Kiev region, Kievo-Svyatoshinskiy rayon). There was studied the effectiveness of the following herbicides: Treflan (active ingredient trifluralin); Frontier Optima (active ingredient dimethenamid-P); Jupiter (active substance imazatapyr); Harnes (active ingredient acetochlor); Prometrex (active ingredient prometryn); Stomp 330 (active ingredient pendimethalin) and the tank mix Treflan + Jupiter, Harnes + Jupiter, Prometrex + Jupiter on Cabanskiy and Serpneviy varieties of white lupin crops. Records of the quantity and composition analysis of weeds was carried out on plots of all variants of experiment in two terms: 30 and 60 days after applying  the herbicides.

To evaluate the effectiveness of herbicides for eradication of weeds, their influence on the growth and development of various plants it is necessary to determine the rate of infestation and species composition of weeds. Quantitative account of weeds on crops of both varieties of lupine on sections of the control variant without herbicide and without weeding, showed that the level of contamination depends on the place of experiments of its pre-crop and vegetation conditions. The results of the determination of weeds in 2013, 2014 and 2015 are significantly different both in quantity and species composition.
In 2013 the number of weeds in average plots of both varieties of lupine made in the first period of account of 36.9 and 55.8 in the second pieces, in 2014 respectively – 185.5 and 130.2 pieces, and in 2015 – 177.7 and of 145.4 pieces per 1 m². The harmfulness of the weed is determined not only by numbers but also their species composition, therefore, for an objective assessment of the pest damage it is essential to make sure to consider the kinds of weeds. In 2013 monocotyledonous annual weeds dominated, which made 77.0 % of the total, in 2014 it made 95.6 % of annual dicotyledonous, in 2015 dicotyledonous annuals made up to 72.2 %.

The main objective of our research was to examine the effectiveness of different herbicides in weeds control. The best results on the efficiency of the overall infestation on crops of both varieties of lupine was obtained on the variant with incorporation of the tank mixture Harnes + Jupiter: the dose of 1.0 + 0.5 l/ha, incorporation after sowing, before emergence. On average over three years, weed control was achieved first runoff accounting for 80.1 % and the second of 78.5 %. Tank mixture Prometrex + Jupiter also showed good results: the dose of 2.0 + 0.5 l/ha, applying after sowing, before sprouting (the level of destruction of weeds over the years of research ranged from 67.4 to 85.5 %) and herbicide Harnes in its pure form: dose 2.0 l/ha, applied after sowing, before emergence (on average for 3 years the level of weeds destruction equaled 79.0 and 76.3 % in the relevant terms).

Key words: white lupine, weeds, species composition, herbicide, active ingredient.