ON THE PROBLEM OF COMPETITION BETWEEN SPRING GRAIN CROPS AND GRASS WEED PLANTS IN AGROPHYTOCOENOSIS
In the article a problem of spring grain crops weed infestation for the period of 2017-2018, in particular naked and glumiferous oats and also spring wheat by weed plants of the family Poaceae is shown. Grass weedy coenosis of the experimental plot for the given crops, on the average, is represented by 3 species : barnyard grass (Еchinochloa crus-galli (L.) Beauv.) - 85,0 % from total number of annual weed plants, coach grass (Elytrígia repens (L.)) - 10,0 %, rough - stalked meadow grass (Poa annua (L.) - 5,0 %.It is determined that the critical grass weed vegetation harmfulness period in spring wheat has made 29-30 days of the combined crop vegetation and weed plants (tillering stage - beginning of leaf-tube formation); naked oats - 27-36 (4 leaves - leaf-tube formation stage); glumiferous oats - 32-34 days (tillering).