During three vegetation periods (2015-2017), the effect of presowing seed treatment with insecticide and the sowing time on seed productivity and quality of spring rape of Accord variety was studied. Pre-sowing seed treatment was carried out 2 ... 3 days before the planting by Tabu insecticide (active substance - imidacloprid), VSK. Rape was sown at different times: early spring (perhaps early - after 5 days from it), medium spring - after 10-15 days possible early, late spring — after 20-25 days from possibly early. The experiments were laid on the sod-medium-podzolic medium loamy soil, the arable layer of moderate cultivation. The early spring period provided a longer rapeseed growing season (an average of 112 days over three years) and a relatively high seed yield of –235 g/m2. The yield advantage at the early spring sowing period is due to the greater 161 pcs per ton of plant standing before harvesting and plant productivity of 1.48 g. productive plants (164 pieces/m2). When sowing rape in medium spring and late spring, preseeding application of insecticide did not affect the yield. Sowing rape in the early and medium spring periods contributed to obtaining seeds with a higher fat content of 45%. The gross yield of fat was the highest 106 g/m2 when sowing rape in the early spring.

In cultivating field crops, the variability of quantitative characteristics is undoubtedly caused by growing conditions and "genotype × environment" interaction. Combined approach to the consideration of this issue showed that the growth of potential productivity of agricultural crops due to selection and cultivation technology adversely affects the resistance of new varieties and hybrids to the influence of abiotic and biotic stresses. This article describes the problem of adapting perennial ryegrass varieties to the conditions of the Udmurt Republic which is one of the reserves of highquality fodder. These studies were performed on sodstrongly podzolic heavyloam soil. The plowing layer of experimental plots had from low (2.1%) to medium (2.6%) humus content, medium (100-101 mg/kg) mobile phosphorus content, from medium (101 mg/kg) to elevated (170 mg/kg) level of mobile potassium. Exchangeable acidity was from medium-acid (рНКСl = 5.0) to close to neutral (рНКСl = 5.6). Results of this research showed that over four years the highest dry matter yield of 3.5 t/ha was formed on average by Malysh variety. The varieties Malysh and Agatboth of Russian selectionwere characterized by high winter hardiness (88.0-89.3%), a slight variability in characteristics was noted for these varieties (variation coefficient 6.9-7.3%) what speaks for their stability. The combination of ecological flexibility (bi = 1.13) and phenotypic stability (S2d = 0.10) of Malysh variety reveals its high adaptive properties.

The aim of the study was to analyze the biochemical composition of dry matter of aboveground biomass and seeds of Akkord spring rape to determine their value when used for feed. Rape was grown in 2016–2019 on sod-podzolic medium loamy soil of middle Urals with a humus content of 1.96 ... 2.25%, mobile phosphorus and potassium 166 ... 268 and 175 ... 273 mg/kg, respectively, рНKCl - 5.4 ... 5.7. The meteorological conditions of the growing season in 2016 were characterized as moderately arid and insufficiently wet (GTC - 0.51 ... 0.73), 2017 - moderately warm and humid (GTK - 1.94 ... 2.36), 2018 - optimal moist (GTK - 1.10 ... 1.70). We analyzed samples of dry matter of the aboveground biomass harvested during the budding period – beginning of flowering, as well as seeds in the phase of full ripeness. The concentration of most of the 70 evaluated chemical elements in seeds, with the exception of magnesium, phosphorus, sulfur, manganese, nickel, copper, zinc, bromine, was lower than in the aboveground biomass. Of the regulated elements (Hg, Cd, Pb, As, Cu, Xn, Fe, Sb, Se, Ni, Cr, Mo, Co) in the dry matter of green mass and seeds used for animal feed, the minimum permissible concentration did not exceed the established norms for all elements. The content of crude protein (22.8%), feed units (1.36 per 1 kg), metabolizable energy (13.0 MJ/kg) in rape seeds exceeded the values of these indicators in the dry matter of aboveground biomass –11.2%; 0.75 feed units and 9.6 MJ, respectively. The amino acid content also tended to increase in the seeds compared to the dry matter content of green mass: the total content of 13 amino acids was 14.14% and 6.40%. The removal of nitrogen from 1 ton of dry matter of aboveground biomass and rapeseed was, respectively, 30.9 and 58.2 kg, phosphorus - 6.5 and 25.5 kg, potassium - 22.0 and 40.5 kg

The reaction of spring rape to the abiotic conditions of the vegetative period, which was manifested by a change in the chemical composition of the seeds, was studied. Among defined 70 chemical elements, 37 were contained in fewer quantities in the seeds of 2015 year harvest, compared to the content in the seeds of 2014 year.