EN
The article presents the graphic method of determining threshold of agrophage control. The method has been shown on the example of weed, though it may be useful while taking decisions concerning the control of other agrophages as well. The only condition for the use of this method is graphic expression of the effect of harmful organisms on the yields of the cultivated plant. The paper also contains an example of the use of the graphic method in determining the economic effectiveness of the treatments; in this case the connection between intensity of the harmful species and the level of ratios of economic effectiveness of protective treatments has been proved.