The paper presents the results of the research on the effect of spring rapeseed ratio in crop rotation on phytosanitary state of crops, oilseed yield, and economic efficiency of rapeseed cultivation. It’s established that the most significant effect is achieved with spring rapeseed ratio of 25% in crop rotation and a 3-year old period of this crop’s return to the same place.

Compacting cereal-flax crop rotation with oil radish in the north-east part of the republic on sod-podzolic loamy soil at the optimum sowing time, it is possible to obtain up to 20 t/ha of oil radish green material containing 1,21 % of nitrogen, 1,57 % of phosphorus, 1,58 % of potassium. The following increases of flax products obtained in 2016-2018 witness the effectiveness of plowdown of radish green material: flax retted stalks – 11 %, fibre – 17 %, long fibre – 15 % in relation to standard crop rotation. Taking into account the products received, additional expenses for crop rotation compaction, as well as cost reduction due to savings of 10 kg/ha of nitrogen active ingredient and refusal of glyphosate application, the economic effect of the technique amounts to 99,3 BYN/ha with 77 % of flax cultivation profitability.

The article provides the information on the effectiveness of sowing sugar beet into mulch from straw and intercrops. The influence of soil cultivation on the formation of mulch and sugar beet yield has been studied. The information is presented on changes in the effectiveness of this technique depending on crop rotation.

The article deals with the results of the influence of herbicides applied to preceding cereals on germination, crop weediness and yield of sugar beet. Recommendations are presented on reduction of herbicides aftereffect using the methods of soil and intercrop cultivation.

When cultivating maize on sod-podzolic sandy loam soil with predominance of annual dicotyledonous weeds, the greatest effect is provided by Lumax (3,5 l/ha) and Adengo (0,35 l/ha) applied at the 3-5 leaf stage. Among the preparations containing sulfonylurea and used against perennial weeds, it’s reasonable to apply the mixture of Doublon (1,0 l/ha) + Aegis (0,2 l/ha) + Adyu surfactant (0,2 l/ha) or Doublon gold (60 g/ha)+ Ballerina (0,3 l/ha)+ Adyu surfactant (0,2 l/ha).

The paper deals with the results of the research on the efficiency of the herbicide Bunt, AS applied to red clover at the 1-2 leaf stage (tillering stage). When the herbicide is applied at a dose of 2-4 l/ha, its biological efficiency is established to be high, which makes it possible to recommend it for applying to red clover under barley cover.

The analysis of the registration of fungicides against wheat diseases in general and against Fusarium head blight (FHB) in particular has been carried out. The conclusion made is that at a background of a sharp increase of the total number of fungicides in 2010-2015, the number of active substances, which were highly effective against FHB, changed slightly. Thereby, new preparations are created on the basis of recombination of already known active substances, to which there is a rather high risk of resistance. Under these conditions monitoring of accumulation of Fusarium infection is possible due to the enhancement of breeding works on the development of highly resistant varieties and use of an anti-resistive strategy for selection and application of fungicides.

The article deals with the long-term results (2013-2019 years) of the research on phytopathological situation in oil flax crops under the conditions of the Republic of Belarus, enabling to identify dominant diseases at various stages of vegetation. A comparative characteristic of variety susceptibility to diseases is presented. The absence of varietal dependence of crop susceptibility to anthracnose has been identified. Harmfulness of anthracnose and Septoria spot has been determined for the first time and their influence on the reduction of oil flax yield has been statistically proven.

The paper deals with the results of the research on competitive relations of seed infection pathogens, their influence on the length of coleoptile and roots of spring wheat seedlings, as well as the effectiveness of protectants. It is shown that the most aggressive is Fusarium culmorum, medium aggressive - Bipolaris sorokiniana, the least aggressive - Alternaria sp. It’s established that with artificial inoculation of spring wheat with seed infection, coleoptile is more inhibited (up to 82,9%) than the primary root system (up to 48,5%). When more aggressive and competitive species F. culmorum and B. sorokiniana interact, their aggressiveness decreases. The studied protectants have high biological effectiveness against seed infection and allow removing significantly the inhibitory effect of infection pathogens on growth characteristics of seedlings.

Fusarium head blight is a dangerous disease of cereals. The goal of this work is to determine the effect of Fusarium head blight on yield and its elements depending on the stage of spring wheat development. The experiments were conducted in the greenhouse. Artificial inoculation was carried out before flowering, at the stage of beginning of flowering and 6 days after beginning of flowering with a spore suspension of Fusarium culmorum. The fungicide was applied prophylactically one day before inoculation or one day after inoculation. Differences in the course of pathogenesis were identified depending on the stage of the plant development at the moment of inoculation: the maximum reduction of ear grain mass at the flowering stage, the minimum - 6 days after beginning of flowering. The maximum effectiveness of the fungicide was manifested with prophylactic application before wheat flowering.

It’s established that duration of a protective effect of seed treatments for blue lupine in the field is limited by the stem stage. Biological effectiveness of preparations against root rot is high at the 4–5 leaf stage – 76,5–92,4%, at the stem stage it decreases to 36,8–86,7%, at the bean formation stage - to 9,1–30,5 % depending on the year of research. On average all the preparations have provided an increase of lupine yield by 2,9–7,4 dt / ha over four years.

The article presents the results of laboratory screening of the effectiveness of protectants under conditions of artificial seed infection with anthracnose and  fusarium. Anthracnose is suppressed with the preparations Maxim XL, SK (1,0 l/t), Maxim XL, SK + Pikus, KS (1,0 + 0,5 l/t), Celest top, KS (1,5 and 2,0 l/t), Vincit, KS (2,0 l/t), Insure Perform, KS (0,4 and 0,5 l/t) by 88,8-100,0 %, with the preparation Prestige (1,0 l/t) t) - by 27,5 %. The effectiveness of the preparations against Fusarium is 56,4–68,8 % lower, except for the Vincit preparation – 81,3 %. Under phytotron conditions biological effectiveness of the preparations against Fusarium wilt disease is 37,9–65,5 % at the 24–25 BBCH stage, and at the stem stage it reduces sharply to 0,0–58, 1%.

The article states the results of the effect of the preparations Biolinum, Zh and Vitaros, VSK applied both separately and in mixture with the micro-fertilizer Ecogum of different brands for pre-sowing treatment of seeds in order to increase the yield of flax retted stalks. It’s established that the use of a protective-stimulating mixture including Biolinum, W, Vitaros, VSK and Ecogum of different brands increases the yield of flax retted stalks in relation to absolute standard up to 12 dt / ha or 27.6 % and to 4.1 dt / ha or 8.0% in relation to Vitaros, VSK.

The paper analyses the results of the research on the influence of sowing rates of components on the yield of binary grass mixtures from alfalfa and festulolium for 2017-2019. It’s established that while constructing binary agrophytocenosis with alfalfa and festulolium it’s possible to regulate their performance with sowing rates of seeds. The validity value (R2=0,94-0,99) witnesses a strong dependence of the yield value on sowing rates of the components.

The studies are carried out on the influence of sowing dates on a plant state before wintering and overwintering of different genotypes of winter rapeseed.  Duration of vegetation period, warmth and moisture availability in soil determinedby sowing dates and climate conditions have a significant effect on winter rapeseed at initial stages of its formation. It’s established that winter rapeseed forms the most  optimum parameters of growth and development in the Central part of Belarus over 61-75 days of summer-autumn vegetation (sowing time is 10-24 August) at summarized active temperatures of 690-927 °С (+5 °С and higher). The general pattern for all genotypes is shown: reduction of dry matter content from early to later sowing dates (in foliage from 20.92 % to 15.09 %, in roots from 31.50 % to 23.64 %). The indicated factors ensure stably high overwintering of the crop – from 85,8 to 93,8 %. A close correlation is identified between biometrical parameters of the plant before wintering (r=0,71-0,86) and overwintering of the hybrid Dnepr F₁.

The paper demonstrates the research results on determining the efficiency of sowing dates and rates of seeds and nitrogen fertilizer doses when cultivating oats on sod-podzolic light loamy and sandy soil. It’s established that for obtaining the maximum grain yield oats should be sown at early time, at the beginning of soil tilth and at the sowing rate of 4.0–4.5 mln/ha. Before sowing nitrogen application should be single in a dose of 90 kg/ha of active ingredient or fractional N₆₀₊₃₀. When sowing in 7 days after early period the sowing rate should be increased up to 5.0–5.5 mln/ha and nitrogen should be applied in a dose of N₉₀ in order to obtain approximately the same yield rate. A fourteen day delay in sowing doesn’t enable to compensate for oats yield shortage because of violating the optimal sowing date due to the increase of sowing rates and nitrogen status.

The results are presented on the change of the yield of a sorghum-sudan hybrid cultivated on sod-podzolic sandy loam soil with the use of a different fertilizer system. The role of nitrogen fertilizers in a dose of N₇₀ and N₉₀ against a background of application of phosphorus and potassium in various doses in green mass formation of a sorghum-sudan hybrid is shown. A comparative evaluation of the yield formation of hybrid green mass under various weather conditions is presented.

The article presents the results of the research on the effect of doses of nitrogen fertilizer on the quality of long rolled and beaten fiber of flax varieties of domestic and foreign breeding against two backgrounds of mineral nitrogen (18 kg/ha of active ingredient and 35 kg/ha of active ingredient). The comparative study enabled to identify domestic varieties, which were able to maintain their number of rolled and beaten fiber at the level of 11 units (Yarok, Dukat, Lada, Mara, Rubin, Malakhit), when increasing the dose of nitrogen fertilizer up to 35 kg/ha. The variety Vetraz was identified, which increased the number of rolled and beaten fiber up to 12 units with the increase of the nitrogen dose up to 35 kg / ha of active ingredient. The varieties Alizee, Silva, Video, Versailles ensuring the quality of long rolled and beaten fiber with number 11 against the background of mineral nitrogen of 18 kg /ha were selected among the varieties of foreign breeding.

According to the two-year studies conducted on sandy loam soil, it’s established that straw plowdown after harvesting maize for grain allows reducing the nitrogen rate to 90 kg/ha, while with secondary cultivation after harvesting maize for silage the highest yield and net income value are obtained with the nitrogen rate of 150 kg/ha of primary nutrients. Straw plowdown to a greater extent influences the yield growth of leaf and stem mass of the “secondary” maize. That is why it’s more cost effective to harvest it for silage in the second year and grow at the minimum of mineral fertilization (N₉₀P₀K_0–90) on soils containing 2,7 % of humus, 200 mg of Р₂О₅, 286 mg/kg of К₂О in the plow layer.

The paper presents the research results on the impact of sewage sludge from city sewage treatment facilities as fertilizers in pure form and organic fertilizers of improved composition developed with their use on the growth, development and yield of maize and the quality of plant products. It’s established that the studied fertilizers are both directly and indirectly increase significantly the yield of maize green mass and the crude protein content in relation to the standard without fertilizers. The content of toxic elements in obtained plant products doesn’t exceed the established standards.

The paper states the research results on the effect of foliar application of nitrogen fixing and phosphate mobilizing preparations on the structure of plants, yield and quality of oil seeds. It’s established that microbial preparation treatment contributes to the yield increase by 4.5-13.6 %. The studied preparations don’t have a negative effect on the content of fat, protein and glucosinolates in oilseeds.

The paper presents the results of the research on the yield of winter barley cultivated on sod-podzolic loose-loamy soil. A significant yield increase of this crop was observed with application of nitrogen fertilizers in a dose of 90 kg/ha of active ingredient and 120 кg/ha of active ingredient in comparison with N₆₀. With changing doses of potassium fertilizers a significant difference in the yield of winter barley grain was established when phosphorous fertilizers were applied in a dose of 90 kg/ha of active ingredient compared to Р₃₀ and Р₆₀. The tendency to winter barley yield increase was observed when applying К120 to sod-podzolic sandy soil with high potassium content. The highest winter barley yield increase was provided by the N₆₀₊₃₀P₉₀K₁₂₀ fertilizer system.

The article presents the results of studying the impact of Belarusian microfertilizers MicroStim, Ecosil growth regulator, Polish microfertilizer Ekolist Bor on the yield and quality of root crops of beetroot. It’s established that the application of the studied micronutrients contributes to an increase in the yield of table beet root crops, as well as to the content of dry matter and sugar in them.

The paper presents the results of the application of growth regulators Ecopin and Ecosil together with microfertilizers MicroStim (Zink, Boron) in cultivating the diploid variety Sapfir and tetraploid variety Marta. It’s shown that their joint application to buckwheat plants at the budding stage makes it possible to obtain the yield of 20.9 dt/ha of the Sapfir variety and the yield of 22.4 dt/ha of the Marta variety.

The paper deals with the results of the research on the efficiency of differentiated foliar application of nitrogen fertilizers to the Lubava variety of spring wheat at different stages of plant growth and development. Carbamide foliar application conditioned the increase of the protein content in grain. Its highest content was obtained when applying N_I5 and N₂₀ at the grain formation stage (BBCH71) – 14.4 and 15.0 % respectively, which is 3.6 and 7.9 relative percent more than in the standard variant.

The article presents the results of the research on the efficiency of fungicides application against Helminthosporium leaf blotch of regular and hulless oats under conditions of its depressive manifestation. It’s determined that under these conditions it’s cost-effective to protect only seed crops.

Research results on the effect of elements of winter wheat cultivation technology on the state of crops and some soil properties are presented. It’s established that under the influence of preceding crops overwintering of winter wheat is reduced by 1,2-3,1%, minimization of soil cultivation – by 0,6-2,7%, preceding crop straw – by 3,0-8,2%. Minimization of soil cultivation increases soil moisture by 0,5-1,4% and reduces ammonium nitrogen content by 17,9-27,3% depending on a preceding crop and plant development stage. With Alister Grande application (0,8 l/ha) the level of weediness of winter wheat crops is not high regardless of cultivation technology

The article presents the results of the research on the impact of various intensification means on the profitability of fibre flax cultivation. On average, over 2011 – 2013 a stable effect in relation to the standard was provided by the following preparations: Kinto Duo with polymer Gisinar M, growth regulators Hydrogumin and Ekosil forte, microelements Adob-Zn and Adob-B, fungicide Amistar extra, insecticide Karate-Zeon and herbicide Secator-turbo. With the use of those preparations the profitability was between 37.7% and 36.4%, while in the standard that indicator was 24.2%.

The paper presents the analysis of overwintering of winter rapeseed in Belarus and long term research on the dependence of the yield on overwintering. The directions and results of breeding for the development of national winter hardy varieties of rapeseed are shown as well as technological ways to increase overwintering of the crop. It’s established that the creation of winter hardy rapeseed varieties adapted to climatic conditions of the republic and strict observance of technical regulations of cultivation of this crop enable to increase its winter hardiness, stability of gross yield and productivity.

On average, over 6 years, coenotic activity index (ICA) of white clover mixed with alfalfa in legume-grass stand was higher than ICA of white clover mixed with other leguminous species, and it decreased in the seventh year of use. ICA of white clover reduced sharply in the 6–7 th year, and the index of white clover mixed with alsike clover or Lotus corniculatus - in the 4th year. Fertilization did not change the ICA of white clover mixed with alfalfa, but in grass mixtures with Festuca arundinacea or alsike clover fertilization reduced the index by 7.3–17.3 %, and lotus corniculatus and/or white clover - it increased by 8.1–16.2 %. The correlation between coenotic activity index and hydrothermal coefficient was weak in grass stands with white clover, white clover and Lotus corniculatus or alfalfa, and moderate in white clover with alsike clover (r=0.33–0.46).

The article demonstrates the results of the research on the influence of sowing time, sowing rates, herbicides, fungicides and growth regulators on crude fat and protein content in oilseeds of the hybrids Almaz F₁ and Rubin F₁ and the variety Hermes of spring rapeseed.

The paper shows that the crude protein content in legume-grass pasture swards varies far more than the content of crude fat, fibre, ash, and especially nitrogen-free extractive substances. It is indicated that the metabolic energy content in green mass of grasses varies slightly and is practically the same depending on a year of cultivation. The formula of calculation of the metabolic energy content in green mass is proposed: ME, Megajoule/kg of dry matter =11.8-0.095 CF, where CF – weight ratio of crude fibre in dry matter (%).

In a weather-favorable year silfium can be used as a crop which provides green mass in summer and autumn ensuring and prolonging the periods of obtaining green fodder and raw materials for harvesting silage from June 7 to September 22. The highest (747.3 dt / ha) green mass yield was obtained at the flowering stage on the variant N₁₂₀Р₉₀К₁₂₀ kg/ha of dry matter + dolomite powder 3.5t /ha. The positive aftereffect of manure (option: manure 40 t/ha + dolomite powder 3.5 t/ha) was manifested in the third year (2016) of silfium life with a yield of 524.1 dt/ha of green mass at the flowering stage.

The paper presents the comparative evaluation of cereals and legume-grass mixtures with festulolium on yield and nutritional value. It’s established that the most optimal agrophytocenoses for festulolium in binary mixtures are formed when festulolium is sown with alfalfa and cocksfoot. Thus, in the first year the highest yield of grass dry matter was observed in the mixture of red clover and alfalfa – 4.4-4.6  t/ha. The second year showed that the most productive agrophytocenoses were formed on the basis of two-component swards with alfalfa. The dry matter yield reached 7.2 t/ha. In the third and fourth years the variants with included alfalfa and cocksfoot (12.8-13.5 t/ha and 10.8-11.1 t/ha of dry matter respectively) were turned to be the most productive in terms of green mass yield. Festulolium sown pure provided the lowest yield, which was 3.7-9.4 t/ha of dry matter, for the third and fourth years of the research. The evaluation of feeding value showed that grass sward was less nutritional than legume-grass one, the crude protein content amounted to 8.8-9.0% with metabolic energy concentration of 9.34-9.63 Megajoule/kg.

The article demonstrates the results of the study and use of plant genetic resources for creation of varieties and hybrids in the Republic of Belarus. The National collection of plant genetic resources formed over 2000-2020 is the most important reserve of valuable sources of the initial material for breeding. Due to long-term field and laboratory studies, donors and sources of valuable traits which are actively used in breeding, have been identified. On the basis of their use 1060 new varieties of plants have been developed. Base, active, working, field, duplicated seed collections as well as core, genetic and training collections of the most economically important crops have been created for the first time in our country. Collections representative in terms of biological diversity have been formed so far and included in the National List of Scientific Objects of National Heritage.

The article describes the main results of developing parental components of F₁ hybrids and the rye hybrid variety Belgi. The studies were conducted using “Pampa” type CMS (P-CMS). It is known that for this type of CMS the development of female components was not a problem, as the frequency of sterility maintaining genes in rye populations was high. The main difficulty was identifying effective fertility restorers. Effective sources of restoring genes, the carrier of which was a primitive Iranian rye population - IRAN IX, were used in the studies. As a result of the conducted research with the use of DNA-typing, female (male sterile) and parental components - effective fertility restorers, were developed, F₁ heterosis hybrids were obtained. The hybrid Belgi, which was the best in terms of a number of economically important traits, was submitted to the State Testing. The description of the hybrid was presented.

The paper demonstrates the results of studying the effect of inbreeding in two generations on formation and productivity of the main ear of winter triticale varieties. It’s established that the value of inbreeding depression is determined by variety specific characters and frequency of inbreeding. The maximum depression effect is observed with the first inbreeding of triticale accessions, with secondary  inbreeding the effect goes down significantly or isn’t observed at all. The wintertriticale varieties Atlet-17, Blago 16, Amulet, Dinamo and Grodno are characterized by a high degree of inbreeding tolerance and/or fast obtaining inbreeding minimum.

The article states the research results on determining the optimum height of plants of 52 varieties of the winter triticale collection from Belarus, Russia, the Ukraine and Poland in order to establish the selection criteria for creating highyield varieties.

The possibility of using cultural liquid filtrate Fusarium culmorum as a selective factor in evaluating variety resistance and selecting spring wheat resistant genotypes is studied. It’s identified that the cultural liquid filtrate concentration of 25 % is optimal for selecting potentially resistant genotypes. For preliminary evaluation of accession’s resistance it’s recommended to use the indicator of a regeneration rate, and selection of resistant genotypes should be made taking into account the length of coleoptile and regenerate roots.

The article presents the results of studying oats accessions from the world collection in order to identify the sources of economically important traits (yield, weight of 1000 grains, number of grains in a panicle, plant height, protein content, hull content, resistance to diseases and lodging, early ripeness) for the use in the breeding process in Belarus. Collection variety accessions of oats are identified and proposed as potential sources of economically important traits of oats, which are high yielding, short-stalked, with a high mass of 1000 grains, resistant to crown rust (7–8 points), with high protein content in grain and low hull content.

The paper deals with the results of a comparative analysis of the performance and physical and chemical features of varieties and variety accessions of winter triticale cultivated in accordance with common and intensive technology. Three groups of accessions have been identified depending on the reaction to intensification. Quantitative traits of the groups and their relation with yield have been evaluated.

The article provides the information on creation of infectious and provocative backgrounds for assessing the breeding material of winter and spring wheat on disease resistance. The dynamics of damage to the collections of accessions is shown over 2003-2016. The analysis of infecting new varieties with diseases is done in comparison with the existing standard. The system of immunological evaluation of cereal crops Fusarium resistance is substantiated.

The study of economically important traits of rice accessions has been carried out for creation of high yield initial material tolerant to lodging. The best accessions have been selected for further study in a breeding nursery. It’s established that a plant height influences to a great extent not only on tolerance to lodging, but also on the yield of crops. Involvement in breeding of new sources adapted to the conditions of the steppe is good prospects for further research.

The paper deals with the results of the assessment of millet collection accessions on yield, chemical composition and nutritional value of green mass. It’s established that on average when harvesting millet plants at the milk-wax stage of ripeness, green mass yield is formed 9.0-97.5% more compared to an earlier harvest (paniculation stage) and depending on a variety. It’s identified that the varieties Askoldo, Veselopodlyanske 311, Kamyshinskoye, Yubileinoye, Kievske 87, Orenburskoye, K-8683 have the highest content of crude and digestible protein. On these indicators they exceeded the standard variety Galinka by 14.8–31.1 and 11.0–30.1 %. In this connection it’s reasonable to use them in breeding for the development of high yield varieties of millet.

The article reflects the results of the evaluation of maize initial material in terms of intensity of grain water-yielding capacity during the pre-harvest period. As a result of the conducted research self-pollinated lines of maize of different heterotic groups were identified with a high rate of grain water-yielding capacity during the pre-harvest period. The possibility of using the identified lines as parent forms was established while developing single-cross hybrids with a high rate of water-yielding capacity. It’s recommended to use the models: Raid х Lacon, Raid х Со-125, Raid х Lancaster, Lacon х Lancaster, Lacon х Со-125 as heterotic models with a high intensity of grain water-yielding capacity during the pre-harvest period.

The paper presents the results of hybridological analysis of the trait “initial growth rate”. Literature and own data on genetics of the indicated trait are summarized. Further directions of breeding of blue lupine intensive varieties are discussed.

The paper summarizes literature data and own results on the change of morpho-physiological structure of a plant in the process of evolution, domestication and breeding of blue lupine. The regularities of changes of a plant bio-morphophysiology caused by human encroachment are presented. The directions of further enhancement of blue lupine plants in the process of intensive varieties breeding are discussed.

As a result of the conducted research the methodology of marker assisted selection in blue lupine has been tried and tested for the following traits: resistance to anthracnose, pod dehiscence, alkaloid content, tendency to vernalization, moisture permeability of a seed coat. The accessions with economically important traits important for breeding in the Republic of Belarus have been identified. The analysis of the results of DNA-typing shows that all the accessions of the studied collection have alleles of the following genes: iucundus (reduced alkaloid content), Ku (thermoneutrality), mollis (moisture permeability of a seed coat), lentus (pod indehiscence). In the studied collection polymorphism has been identified through the pod indehiscence gene tardus. About 20 % of the accessions possess a wild allele determining an undesirable trait of pod self-dehiscence during the maturation process. Anthracnose resistance genotyping allows identifying accessions with resistance alleles

The possibility of in vitro introduction of green pea was studied. It was established that Domestos (15 %, 30 minutes’ exposure) and Chloramin B (8 %, 25 minutes’ exposure) were optimal sterilizing agents for green pea. The maximum intensity of callus formation was observed in the variants with weak sterilizing agents: alcohol (77.3 %) and Khozyaiushka (123.8%). Direct morphogenesis was observed in all the variants of the experiment, regardless of the way of sterilization.

The article presents the results of long-term studies of the gene pool of forage grasses in order to identify the sources of economically valuable traits for their application in the breeding process in Ukraine. The creation of a genetically diverse material enables to use more effectively the potential of forage grasses in breeding, which will create the prerequisites for increasing their yield by 15%.

As a result of transfer of the domestic ryegrass diploid variety Pashava with high winter hardiness and resistance to foliar diseases to tetraploid basis, high yield morphologically similar tetraploid variety populations were formed and included in the breeding process.

The article analyzes histological elements of oil flax stalk; variability of these elements is evaluated. It’s efficient to use stalk anatomic parameters as selection criteria in oil flax breeding for resistance to lodging and productivity.

The article demonstrates the results of the use of a multi-criteria evaluation method at different stages of fibre flax breeding for optimizing the breeding process on the example of culling of the second generation hybrids obtained according to the full diallel mating design. The results of the comprehensive assessment of 439 plants are presented. It’s established that the best integrated assessment indicators are obtained due to the following crosses: Yarok x Smena and Yarok x Lider.

The paper presents the results of the research on comparative analysis of formation of indicators of the yield of straw, flax retted stalks and seeds of flax accessions, depending on corolla color polymorphism. It is shown that accessions with a white color of corolla of different origin are inferior in terms of a set of economically valuable traits to blue-colored accessions selected in Belarus and Ukraine, which makes it difficult to use corolla color as a marking trait in breeding process.