Features of morphometric indicators and productivity of hemp plants under the influence of reducing herbitoxic stress

The study of the effect of herbicidal protection using stimulating substances and liquid mineral fertilizer on the morphometric parameters and productivity of hemp plants was carried out in 2021–2023 in the conditions of the Federal Research Center for Bast Fiber Crops in the Penza region. The ongoing protection against weeds in the industrial hemp agrocenosis contributed to a reduction in the biomass of dicotyledonous weeds to 82 %, and of cereals to 96 %. Protective measures ensured an increase in morphometric parameters and productivity of hemp plants. To a significant increase in plant height, technical and inflorescence length by 21.0; 15.0 and 9.0 cm, internode length by 1.0 cm and stem diameter by 0.9 mm resulted from the application of Artafit + Lontrel grand + Izagri Vita compared to the control without the treatment. The content of drying oil in seeds increased when spraying crops with liquid mineral fertilizer, treating seeds with stimulating preparations, and using herbicides Lontrel grand and Miura by 0.54...0.56 and 0.45...0.96 %, respectively. An increase in the weight of 1000 seeds by 6.7 and 6.5 % was facilitated by foliar feeding and the use of compositions of AgroVerm Screen + Lontrel grand and Lignohumate + Miura preparations. The best increases in the yield of stems and seeds were formed when plants were sprayed with Izagri Vita fertilizer, Miura herbicide and seed treatment with AgroVerm Ekran 1.64 and 0.38 t/ha, as well as when using the herbicide Lontrel grant and the growth regulator Artafit -1.58 and 0 .32 t/ha. In these options, oil collection increased by 0.21...0.23 t/ha; fiber collection - by 0.6 t/ha.