RESULTS WITH WEEDS COMPETITION AND THEIR CONTROL IN SOYBEAN CROP

In the area of heavy clay soils in the South, soybeans are weedy at high levels. Currently, new, diverse and especially complex results are still required in the success of weed-free soybean crop. On the one hand, studying the relationship between soybean plants and weeds is important in determining the best measures to reduce competition. In conditions of natural weeding, large amounts of biomass are formed, on average 13.48 t/ha. In the weedy control, soybeans produce in most years between 200 and 600 kg/ha, which represents about 20% of the total. From the structure of the weeds, AM were at 61%, AD at 26%, and PD constituted 13%. The interaction with weeds resulted in total biomass losses of 2/3 of normal, and the accumulation of dry weight in grain it was reduced to a rate of only 1.1 g/m(2)/day, compared to the normal 10.2 g/m(2)/day. Mechanical and manual weeding brought a total production increase of 1938 kg/ha, and herbicides favored the formation of grain production of over 2000 kg/ha. In the current conditions of climate change, the reduction of herbicide doses must be done with great caution