WEED COMPONENT FORMATION OF WHITE MUSTARD AGROPHYTOCENOSIS DEPENDING ON AGROTECHNICAL MEASURES

The article focuses on the research results concerning the effect of long-term application of basic tillage systems and fertilizing on weed component quantitative indicators of white mustard agrophytocenosis. The research was being conducted in four-field crop rotation of the stationary experiment under conditions of RightBank Forest-Steppe of Ukraine during 2009-2016. It has been proved that the application of subsoil system of basic tillage results in 67% increase of weed quantity in case of mineral fertilizing and 207% in case of organic-mineral fertilizing as compared to conventional tillage. Weed vegetative wet weight increases by 69% with mineral fertilizing and by 52% with organic-mineral fertilizing in case of subsoil tillage in comparison with conventional tillage. Mineral fertilizing decreases vegetative wet weight and total amount of weeds by 12 and 40% respectively in comparison with organic-mineral fertilizing system. 14 species of weeds have been found in white mustard agrophytocenosis, among them the dominant ones are Setaria glauca L., Chenopodium album L., Capsella bursa-pastoris (L.) Medik., Galinsoga parviflora Cav., Amaranthus retroflexus L. The quantity of weed species increases with organicmineral fertilizing and mineral fertilizing by 18 and 20% respectively in case of subsoil tillage as compared to conventional tillage. The quantity of perennial and wintering weed species increases in white mustard sowings with organic-mineral fertilizing and mineral fertilizing in case of subsoil tillage. The most favorable phytosanitary state of white mustard agrophytocenosis with mineral and organic-mineral fertilizing occurs in case of conventional tillage which includes stubble disking of previous crop to a depth of 10 to 12 centimetres immediately after cropping and ploughing in 10-12 days to a depth of 25 to 27 centimetres