Research results of the studies on the productivity of specialized cereal crop rotations with different level of saturation by cereals are presented in the article. The results of 12-year researches showed the efficiency of alteration of agricultural crops of different biological groups (crop rotation). It was established that the yield of cultivated crops depended not only on their placing (alteration) in a crop rotation but on a rotation type and cereal concentration (saturation) in it. The comparative evaluation of crop rotations by the yield per 1 ha and sowing of fodder units, digestible protein, and grain was given.

Research results of the study on the dependence of winter wheat grain yield on preceding crops, methods of basic soil cultivation and the level of plant nitrogen nutrition are presented in the article. It was established that on average for two years, the cultivation of winter wheat after pea using chiseling and N_70+70+20 gave the highest grain yield (6.13 t/ha). The share of the effect of the studied factors could be arranged in the following decreasing sequence: nitrogen – preceding crop – soil cultivation.

Research results of the study of the effects of different basic soil cultivation methods on soil moisture, crop contamination and yield of spring rapeseed oilseeds are presented in the article. It was established that the maximum crop contamination by weeds after 30 days of the herbicide use was registered using annual surface tillage, late ploughing and spring ploughing, while the highest soil moisture for the period of vegetation was registered at combined soil cultivation including 50% of chiseling. Minimalization of soil cultivation in spring rapeseed growing did not have positive effect on rapeseed yield. The yield, to a great extent, depended on ploughing terms.

Study results of herbicide effect on sugar beet yield and weediness of the crops are presented in the article. It was established that the use of the mixture of such herbicides as Biceps Garant and Pilot (1.0 + 1.5 l/ha three-time) provided the highest efficiency under the conditions of low water availability in soil. The mixture of herbicides Biceps Garant and Pilot Plus (1.0 + 1.5 l/ha three-time) was the most efficient at the low air temperature and substantial precipitation.

Research results of the study on herbicide effects on weediness of crops, the structure and volume of grain yield of new recognized yellow lupine variety Vladko are presented in the article. It was established that soil herbicide Primextra Gold TZ SC, used at the rate of 2.5 l/ha before sprout emergence following by the treatment with herbicide Pilot SC (2.0 l/ha) used after the vegetation, provided the highest effect in yellow lupine protection from weeds. In that case, weed loss made up 90.9-100% depending on a weed kind, and yield increase was 1.34 t/ha as compared to the control.

Research results of the study on the effect of Hussar Active Plus herbicide on crop weediness and grain yield of winter triticale are presented in the article. It was established that the highest economic effect was obtained by the use of Hussar Active Plus herbicide at the rate of 0.6 l/ha when there were no perennial dicotyledonous weeds in the crops.

It is impossible to obtain high maize yields not using herbicides due to high field contamination and great variety of weeds. Comparative evaluation of the effect of different herbicides on crop contamination, plant height and maize productivity for period 2016-2017 is given. It was established that herbicide use had significant effect on the decrease of crop contamination. As a result, the saved yield of maize green material was 39-45.1 t/ha, and the saved dry matter yield made up 16.1-18.3 t/ha.

Research results of the study on the effects of herbicide Global, SC (imazamox, 40 g/l), Group of Companies “Zemlyakoff”, Russia, on pea weediness and yield are presented in the article. It was established that the herbicide application at the rate of 0.75-1.0 l/ha before sprout emergence and in the phase of 1-3 pairs of pea true leaves provided high effect against annual dicotyledonous weeds and grasses and could be recommended for the use in pea growing at agricultural enterprises of Belarus.

Research results of comparative evaluation of the efficiency of pre-emergence use of herbicides Sencor Ultra SC (1.2 l/ha) and Bandur Forte SC (3.0 l/ha) in potato cultivation are presented in the article. It was established that the application of Bandur Forte SC (3.0 l/ha) increased pure income by 1274.2 USD/ha and profitability by 39.3%, and decreased potato prime cost by 16 USD/t.

Research results of the estimation of plant height of 15 spring soft wheat cultivars and varieties of RUE “Research and Practical Centre of NAS of Belarus for Arable Farming” breeding are presented. Strength and nature of correlation between plant height and fertilizer nitrogen reimbursement by grain yield increase at medium and high nitrogen nutrition level is shown.

Research results of the study of basic grain yield structure elements of 15 spring soft wheat cultivars and varieties of RUE “Research and Practical Centre of NAS of Belarus for Arable Farming” breeding are presented in the article. The amount of variation of yield structure elements, strength and nature of their correlation with grain yield using different rates of nitrogen fertilizers (100 and 160 kg/ha a.i.) are shown.

The results of the evaluation of economic efficiency of chelate micro fertilizers (foliar application) on maize green material are discussed in the article. Positive effect of the micro fertilizers (Sugar Mover, Extra Power) on the green material yield of maize hybrid Polessky 202 under stress conditions (drought, low air temperatures in the maize vegetation period) was registered.

Research results of the evaluation of biological and economic efficiency of such seed treaters as Insure Perform SC (0.4-0.5 l/t) and Kinto Duo (1.5—2.0 l/t) in millet protection from diseases are presented in the article. It was established that biological efficiency of those products in the control of loose smut agents was 85.4-93.2% depending on pesticide rates. The use of the studied seed treaters provided significant grain yield increase equaled to 0.12-0.61 t/ha or 4.9-25.2%. The highest yield increase was obtained using Insure Perform SC (0.5 l/t).

Comparative evaluation of the effect of fungicide protectants on contamination, laboratory and field germination of seeds, plant height and maize productivity at sowing at the end of April and in the beginning of May is given. It was established that fungicide protectant Maxim XL provided the highest field germination of seeds particularly at early sowing terms under the conditions of warmth deficiency. The maximum yield of green material and dry matter was obtained at sowing in the first ten-day period of May and using Maxim XL and Vershina, but if the seeds had lower moisture sowing should be conducted two weeks earlier

Research results of the effects of disinfectants and protective-stimulating mixtures used for presowing seed treatment on the morphological and anatomical characteristics of fibre flax stems are presented in the article. Incrustation of seeds with such mixtures contributes to the yield increase of common and long flax fibre with the improvement of its quality.

Special aspects of the dynamics of kernel formation and weight accumulation of winter wheat var. Avgustina in vegetation periods 2016-2017 are discussed in the article. It was established that at optimal supply of the crops with nutrients and sufficiently effective plant protection from leaf and ear diseases, yield formation and quality of winter wheat, to a great extent, depended on weather conditions in the period of grain filling.

Evaluation results of the use of such retardants as Moddus, Terpal, Seron, and CCC 750 on spring oat crops are presented in the article. It was established that CCC 750 retardant at the rate of 0.9-1.25 l/ha could be used on oat crops at stage DC 31-32 for the control of plant height and minimizing of lodging risk.

Research results of the study on the efficiency of the application of retardant CeCeCe 750, SC on oat crops cultivated in Smolevichi and Rogachev regions using different levels of nitrogen nutrition are presented in the article. It was established that in those regions, the use of N90 in one or two steps was the most efficient measure for the fulfillment of oat production potential. The application of retardant CeCeCe 750, SC at the rate of 1.0 l/ha in the beginning of the stalk-shooting stage (DC 31-32) could be used for the lodging risk reduction, yield increase and oat grain quality in the years with the sufficient levels of water availability.

In the period of studies the ubiquity of Alternaria in winter rape crops in Belarus is determined. Mycological studies have indicated the dominance of the fungus A. tenuissima with the frequency of occurrence 32.3%. High localization is observed in the fungus A. alternata (83.9%) from seeds. The fungi A. brassicicola and A. tenuissima with relatively equal frequency have separated from seeds and leaves. Variability of pathogenic properties of fungi of the genus Alternaria is marked. But in general, isolates of the fungi A. brassicicola, A. tenuissima and A. alternata are considered to be highly pathogenic.

Research results of the study on the racial composition of Pyrenophora triticirepentis agent are presented in the article. The conducted researches have shown that races 1, 2, and 8 of the given disease occur on the territory of the Republic of Belarus.

Research results of the study on the effectiveness of the use of fungicides, microelements and their tank mixtures on sugar beet crops are presented in the article. It was established that the application of fungicide Amistar (0.6 l/ha) provided the highest root yield. Combined application of fungicides and microfertilizer Polikom Svekla was effective only at the use of Rex Duo, Prosaro and Kolosal Pro on sugar beet crops.

Research results of biological and economic efficiency of Skyway Xpro EC against Fusarium head blight and Fusarium grain blight of winter wheat are presented in the article. It was established that the use of Skyway Xpro EC (1.25 l/ha) saved 1.4 t/ha of the yield (+22.5% as compared to the control) on average for three years, while the use of standard product Prosaro EC (1.0 l/ha) saved 1.03 t/ha (+16.6%). Rate reduction to 1.0 l/ha did not lead to a significant decrease of economic efficiency level.

Research results on the estimation of the efficiency of different winter wheat cultivation technologies are presented in the article. It was established that the common technology was the most efficient one when the crop was grown for forage grain, while for the production of food grain, it was better to use the intensive technology. The higher pure income was obtained due to the application of N₇₀₊₅₀ after ploughing or N₇₀₊₇₀ after chiseling.

Economic efficiency of growing of maize hybrids different by early ripeness by the results of field experiments 2016-2017 is presented in the article. It is shown that middle-early (FAO 200-220) and early (FAO 180-190) hybrids are suitable for growing for grain, while mid-ripening (FAO 230-250) and middle-early ones are used for silage. Silage making is more profitable than grain drying, pure income of which is higher by 280.3-298.1 roubles per ha.

Research results of the evaluation of the efficiency of barley cultivation and complementary seeding of clover and the first year clover in a link of grain-grass crop rotation are presented in the article. It was established that the highest total economic impact at barley cultivation with complementary seeding of clover and the first year clover was obtained due to annual application of chisel ploughing in the crop rotation link.

The possibility of optimizing the preparation of flax retted stalks by the method of dew-stain with the use of natural humin fertilizers in the treatment of spread straw flax fiber under the conditions of acute precipitation deficiency (GTK-0.8) and excessive humidification (GTK-2.0) was studied. Treatment of straw by fertilizers a day after flax tearing improved the separation of fiber from the stalk wood and accelerated the process of preparation of retted stalks by 2-4 days, but did not affect the number of retted stalks and long scutched fiber. However, the fiber obtained from the treated straw had higher flexibility and tonic values, and when the moisture of the straw was excessively increased, fiber strength and yarn quality were also higher.

Research results of the effects od sowing terms and rates on yield and quality of Brassica campestris oilseeds growing for food aims are presented in the article. It was established that the highest oilseed yield (2.73 t/ha) was obtained at sowing in the second ten-day period of August; the rate of sowing was 2.0 mln./ha. Using the above mentioned term and rate provided the maximum fat and protein yields, i.e. 28 and 0.54 t/ha, respectively. Improvement of cultivation technology elements contributed to the increase of fat yield per area unit by a factor of 1.7 and the increase of protein yield per area unit by a factor of 1.3.

Data on the ¹³⁷Cs and ⁹⁰Sr transfer factors in the production of winter rapeseed cultivated on soils of different genesis and granulometric composition are presented. It is shown that the radionuclide’s transfer factors to winter rapeseed produce decrease when cultivating crops on soils containing more physical clay. The maximum density of radionuclides contamination in soil was determined for cultivation and obtaining of normatively produce of winter rapeseed for different directions of use. It is established that the cultivation of winter rapeseed in the radioactive contaminated territory in the Republic of Belarus is limited by the ⁹⁰Sr contamination density in soil.

Research results on sowing rates of alfalfa var. Buduchynya using spring and summer terms of open sowing are presented. On average for four years, spring term alfalfa exceeded summer term in green material by 12% and in dry matter by 13.7%. Increasing of sowing rate from 9.0 to 21 kg/ha of viable seeds did not provide significant yield increase.

Alfalfa var. Buduchynya sown on sod-podzoloc soil in the central part of the Republic provided sufficiently high yield at three cut system for three years. Its viability after cover crop harvesting was 66.4% and overwintering was good. 1 kg of alfalfa dry weight contained 18.3-18.7% of crude protein; provision of 1 fodder unit with digestible protein made up 185-194 g. Sowing of alfalfa at the rate of 4.5 mln seeds/ha at barley harvesting in the milk-wax stage of ripeness for grain haylage was the most productive. That sowing method provided high profit and cost efficiency.

Comparative evaluation of perennial ryegrass and festulolium can be carried out by such index as “water deficiency of leaves” in the period of soil drought when full field soil water-holding capacity is from 20 to 40%. As a result of the researches, 4 festulolium variety samples (variety Udzyachny, № Fl_a-14, № Fl_a-17, № Fl_ol-512-1) and 6 perennial ryegrass variety samples (variety Huslyar, № 617, №720-1, № 716-1, varieties Khutorskoi and Pashavy) have been identified. The mentioned varieties and variety samples are distinguished by higher drought hardiness as compared to other variety samples.

Estimation of the productivity, cenotic activity and nutritional value of beancereal herbages with an additional bean component on peat-mineral soil was carried out. It was established that on that type of soil the bean-cereal herbages formed high productivity: the yield of green mass was 40.12-41.61, t/ha, the yield of feed units was 7.06-7.49 t/ha, crude protein 1.52-1.59 t/ha. The nutritional value of the feed was 0.93-0.96 f. un. The main bean component in bean-cereal herbages was white clover. Inclusion of the additional bean component in the grass mixture (red clover, alfalfa, birds-foot trefoil, sainfoin) did not contribute to a significant increase in the productivity and nutritional value of herbages.

It was established that combining is the best use of mixtures on the basis of festulolium and alfalfa, while festulolium and white clover mixtures can be used both as pastures and in combined mode using herbages of the first cut as hayfields. Mixtures on the basis of Bromopsis inermis can be used for haymaking (2-3 cuts) or for haymaking (2 cuts) in spring and summer and then for pastures in the remaining period of vegetation.

Biennial results in the formation of perennial leguminous herbages of East goat's-beard, birdsfoot deer vetch, purple medic with intensive three-hay-crop use, depending on foliar application with microelements and biologically active substance are presented. It is revealed that in on average for two years of hay use, the herbage yield was determined most of all by studied species of perennial legumes, to a lesser extent, it was determined by the use of microelements and biostimulators. On average, over two years of haymaking use (2016 - 2017), the yield values were as follows: 280.8-314.5 kg/ha of purple medic dry matter, 260.3-297.6 kg/ha of East goat'sbeard dry matter, and 181.1-201.5 kg/ha of birdsfoot deer vetch dry matter.

The results of studies on the effect of desiccation on yield and sowing qualities of Sudan grass seeds under the soil and climatic conditions of the southwestern part of the Republic are presented.

Data on the green material yield of mixed crops of silage (sunflower, maize and sorghum) and leguminous (vetch, pea and lupine) crops obtained in the field experiment are presented. Transfer factors of ¹³⁷Cs and ⁹⁰Sr into green material of mixed crops of silage and leguminous crops and the maximum density of radionuclide contamination of sod-podzolic soils have been determined. The above mentioned parameters allow to obtain the green material corresponding to the republican permissible levels of ¹³⁷Cs and ⁹⁰Sr contents in agricultural products and feeds.

Predictive models of crude fibre content in grain spring barley were designed by near infrared spectra using the modified partial least square method and artificial neural network. The estimation of the received calibrations and results of their testing was carried out. The conclusion on the possibility of the use of near infrared spectroscopy for the definition of crude fibre content in grain of spring barley was drawn.

As a result of the gas chromatography-mass spectrometry studies, about 40 components were identified, the main ones being monoterpene hydrocarbons: ocimene, α-thujene, α-pinene, β-ocimene, o-cymene, β-pinene, terpinolene, γ-terpinene. NP-13/2 and NP-14/5 are promising samples, which are a valuable source material for further breeding work with the aim of creating varieties of nigella with a high content of essential oils.

Study results of the world spring soft wheat collection of Plant Genetic Resources Bank of the Republic of Belarus are presented in the article. The isolated sources of economic characters which can be used in the breeding process are discussed.

Research results on the identification of correlation dependence between basic economic characters in 40 winter triticale collection varieties from Belarus, Russia, Ukraine and Poland with the aim of the determination of selection criteria in plant breeding for high productivity are presented.

Analysis results of general and specific combining ability by plant height and yield structure (thousand-kernel weight, kernel number per panicle, productive tilling capacity) using the method of full diallel crosses are presented. The best varieties for breeding for yield have been identified.

Literature data on structure changes in plants during evolution, domestication and breeding of blue lupine are generalized in the article. Regularities of changes in plant organisms due to human intervention are presented. It is shown that intensive varieties with high rates of growth and xeromorphic leaf structure promote the stability of high yields. Express-methods of the selection of desirable genotypes were developed.

Main results of self-pollinated rye lines study on the ability of male sterility maintaining and pollen fertility restoration in generations for the G-type CMS are presented in the article. The frequency of occurrence of non-restorer genes in rye populations is established. Male sterile analogs of the selected non-restorers (female components of heterozygous rye hybrids) and experimental F1 rye hybrids based on the G-type CMS were developed. They were studied for the main economic traits and the best genotypes were identified.

Study results of new winter soft wheat breeding material in the Central zone of the Republic of Belarus are presented and analyzed. The results of the competitive variety trials allowed to identify the variety samples yield of which was higher than in the standard or was at the standard’s level depending on the level of intensification. The contents of crude protein and crude gluten in those variety samples corresponded to the State Standards 9353-90 applicable to winter wheat grain used for food aims.

Research results of the study of collection field pea accessions of different ecological and geographical origin from the VIR world collection by the main economic characters for the identification of sources for their use in breeding process are presented in the article.

Research results of blue lupine initial material of different origin and genotyping of blue lupine (Lupinus angustifolius L.) accession collection using DNA markers associated with the genes controlling phenotypic manifestation of economic characters are presented in the article. The accessions possessing economic characters and important for breeding in the Republic of Belarus were identified.

Research results of blue lupine breeding of grain and universal use are presented in the article. Study results of new blue lupine variety samples in competitive variety testing and against an infection background are discussed. In the competitive variety testing, the variety samples with economic characters, high productivity and certain tolerance to anthracnose which are suitable for breeding in the Republic of Belarus have been identified. Two of the identified variety samples were selected for the transfer to the State Inspection for Variety Testing for study

The results of experimental researches on heterosis rapeseed breeding are discussed in the article. General and specific combining ability of new initial material has been determined. The most valuable self-pollinated winter rapeseed lines have been developed and selected by a complex of economic characters. Possibilities of the use of the selected material in heterosis breeding are presented.

The analysis of the study of millet accessions of different ecological and geographical origin from the VIR world collection under field conditions with the aim of identification of sources of economic characters for further use in the breeding process is presented in the article.

The results of the study of the fitness of recognized Belarusian oil flax varieties for oil production are discussed. It is shown that the variation of range by yield was from 0.7 to 4.0%, while the oil yield varied more significantly i.e. from 7.2 to 20.6%, due to different oil content in oilseeds. The highest yield of oil was provided by Salyut variety. The varieties were also slightly different from each other by the content of α-linolenic acid (omega-3). The minimum content of omega-3 in oilseeds was obtained in Opus variety.

Study results of 15 oil flax lines in breeding variety trials are discussed in the article. 4 early-ripening forms with vegetation period of 81.5-83.0 days, 7 samples with plant height of 58.6-59.8 cm, and 5 lines highly resistant to Fusarium blight (disease development from 5.4 to 8.6%) were isolated. 3 forms exceeding standard Salyut by seed yield by 10.9-13.6% and 3 variety samples with the yield of 2.45-2.49 t/ha were identified. The lines with thousand-seed weight of 6.97-7.23 g, oil content of 43.8-45.8%, and oil yield of 1.0 t/ha were selected.

Nigella sativa L. is an essential oil, spicy aromatic crop of Ranunculaceae family. The current main direction in Nigella sativa L. breeding is the development of varieties adapted to growth conditions of the Republic of Belarus.
The researches on the study of Nigella sativa L. artificial pollination terms conducted in 2014-2015 revealed the following regularities: the highest percentage of fruits (95%) was obtained by pollination of a flower in the 6th phase of development with freshly collected pollen from 6.00 to 10.00 a.m., while the smallest percentage (60%) was when pollinating a flower in the 5th development phase with pollen stored for two days from 2.00-6.00 p.m. Setting of fruits (seeds) at pollination at different time intervals was on average 74.1%. The best phases of Nigella sativa L. flower ontogenesis, holding period of pollen, and the most suitable time intervals for artificial pollination were identified for further breeding work on Nigella sativa L. intraspecific hybridization.