The results of long-term researches on the agronomic efficiency of major field crops as well as different types and kinds of resource-saving crop rotations on sod-podzolic sandy loam soils of the central part of Belarus are presented in the article.

The research results on repeated fiber flax crops when growing on sod-podzol soils are presented in the paper. The degrees of the increase of development and distribution of flax infections, and the decrease of flax yield and product quality in monoculture farming in the second and third year have been established. The economic evaluation of fiber flax growing in monoculture and in grain-flax crop rotations is given.

The assessment of the productivity of farm crops depending on the system of fertilization on the drained sod-podzolic soils of Ukraine Polesie is presented in the article. It has been established that the use of green manure crops in a grain-forage rotation (2-nd clover mowing, peas) in organic fertilizer systems increases crop rotation productivity by 30-32% and improves topsoil agrochemical properties. The best variant for winter wheat was at the application of mineral fertilizers in combination with green manures when the yield was 4.2 t/ha, the yield of maize was 58.3 t/ha. Using this fertilizer system, the productivity of the crop rotation was also the highest one and equaled 5.8 t/ha.

Research results concerning the influence of fertilization system and plant protection of bread spring wheat on yield capacity formation, quality of grains and seeds are given. It is shown that the highest yield capacity (5.12 t/ha) in Elehiia Myronivs`ka variety and (4.86 t/ha) in Simkoda Myronivs`ka variety is formed when using a technology with intensive chemical protection and application of fertilizers at the rate of N₉₀P₆₀K₉₀ and with the additional fertilizing with N₃₀ at stage IV of organogenesis. The use of intensive technology of growing management practice and application of phosphate and potash fertilizers before basic tillage and additional fertilizing with N₃₀ at stages IV and X of the organogenesis increased both gluten content in the studied varieties by 6.3 and 5.0% and protein content by 3.7 and 3.1%.

The research results for the determination of the yield of new recognized and promising spring soft wheat varieties and accessions of RUE “Research and Practical Centre of NAS of Belarus for Arable Farming” breeding as well as the determination of total (economic) and specific (standard) nitrogen yield in wheat crops at harvesting time using different levels of plant nitrogen nutrition are presented in the article. It is shown that the specific nitrogen yield increases with the use of nitrogen fertilizers and decreases with the cultivation of more yielding spring wheat varieties.

The research results on the study of the effect of sowing terms of such two malting barley varieties as Brovar and Silfid on the formation of yield and yield structure elements are presented in the article. It has been established that delay with sowing leads to the decrease of the yield, thousand kernel weight, number of productive stalks per 1 m², and kernel number per ear in Brovar and Silfid varieties.

Based on the studies conducted in 2011-2013, the effect of sowing terms and varietal characteristics on the affection of winter wheat plants by ear diseases is proved. The affection reduces with the removal of the sowing terms to later ones. The removal of the sowing terms to the accepted level decreases the profitability of winter wheat seed production by 12%. When the removal is made to the late term, the decrease is by 30.6% as compared with the optimum sowing terms.

On the sod-podzolic sandy loam soils of the central part of Belarus, the optimal sowing rates for spring rape hybrids Almaz F₁ and Rubin F₁ are 1.2-2.3, 1.3-2.3 and 1.3-2.2 million germinable seeds per hectare, respectively. Lowering of the sowing rate to 1.0 million/ha as well as its increase up to 2.5 million germinable seeds/ha leads to significant yield decrease of the crop. Sowing rate variations in the spring rape hybrids and varieties from 1 to 2.5 million germinable seeds do not have any influence on fat and protein content in the oilseeds.

The evaluation results of the use of such retardants as Moddus, Seron, Terpal, and CCC 750 in spring oat and spring triticale crops are presented in the article. It has been established that retardant CCC 750 or its analogues can be applied at the rate of 0.9-1.25 l/ha in oat and spring triticale crops in DC 25-30 and DC 31-32 stages for plant height control and lodging reduction.

Results of two-year researches on retardant use on one of new dwarf winter wheat variety Avgustina of RUE “Research and Practical Centre of NAS of Belarus for Arable Farming” breeding are presented in the article. The purpose of the researches was to study responsiveness of the given variety to different application methods of Moddus retardant. The variety was cultivated on the provocative background of mineral nitrogen at the rate of 200 kg a.i./ha. It was established that under the favourable development conditions of winter wheat plants in spring and summer 2014, Moddus retardant did not allow to obtain any statistically significant yield increase in all the studied variants. At the same time, in 2015 under the conditions of insufficient precipitation, the application of the given product significantly decreased the yield in all the variants of the researches.

The efficiency of application of growth regulators in crops of winter (cultivars Impuls and Prometei) and spring (cultivar Dublet) triticale is shown in the article. It is established that depending on the method of treatment and genotype, growth regulators have an impact on resistance to lodging and allow to save from 0.08 to 0.82 t/ha of the yield.

The results on studying of growth regulators on the formation of the length of first three internodes, culms thickness, changing of the diameters of the lower internodes are presented in the article. The degree of stimulation or inhibition of the linear dimensions of stems depends on cultivars, growth regulators, methods of application and weather conditions of the vegetative period. The reduction in linear growth of stems was 5.7…12.5% compared to the control.

The results of three-year researches on yield formation and crude protein content in spring triticale (cv. Uzor) grain at two levels of cultivation technology intensification are presented in the article. It has been established that the spring triticale cultivation at the higher level of cultivation technology intensification provides significant grain yield increase of 0.53 t/ha not lowering the crude protein content.

A comparative study of the influence of growing conditions on canopy chlorophyll index and its components during the reproductive period of development in high-yielding varieties of winter wheat was conducted. It was shown that the influence of the growth conditions on the amount of chlorophyll in the leaves of shoots per unit of soil area depended significantly on the variety. It was established that the formation of high yield of winter wheat (8-10 t/ha) necessitate the chlorophyll index of canopy at the flowering stage to be about 2-3 g of chlorophyll/m² and not less than 0.7-1.5 – at the milk-wax stage.

High potential productivity was identified in soft winter wheat genotypes of universal type: Lutescens 37090 (MІP Dnіprianka), Erythrospermum 36802 (Gratsіia myronіvska) and Lutescens 36921 (Trudіvnytsia myronіvska) which were studied with four predecessors and different sowing dates. They were transferred to the State Variety Testing in Ukraine. New varieties Horlytsia myronіvska and MІP Valensіia are characterized with valuable economic traits and significantly exceed the standard variety in terms of yield. It has been found that the promising genotypes are the closest to the model variety both in general and by each productivity parameter.

Research results on the study of the effect of urea foliar application at the dose of N₃₀, the use of Cerone growth regulator (0.8 l/ha) at DC 37 stage and home-produced fungicides on the yield of new fodder barley varieties are presented in the article. The evaluation of the economic efficiency of the studied technology elements was conducted.

Predictive models of general nitrogen and dry matter contents in straw of spring soft wheat are designed by near infrared spectra using the modified partial least square method. On the basis of calibration characteristics and the results of theirs testing, the following conclusion can be made: near infrared spectroscopy for the determination of general nitrogen and dry matter contents in straw of spring soft wheat can be used.

The results of mixograph analysis of winter triticale varieties and advantageous accessions in comparison with wheat and rye for 2013-2014 are presented in the article. The triticale accessions were characterized in whole by low resistance to setting, genotypic and modification variability of “peak viscosity” index as well as slow retrogradation of starch. The complex of rheological indices was used for the characterization of genotype baking potential and the evaluation of genotype availability as raw materials for making of bakery and confectionary products.

The research results on the study of Pyrenophora tritici-repentis causative agent are presented in the article. The identification of the disease under field conditions was done. Methods of agent isolation in pure culture were developed. Nutrient media of different composition were studied in order to find the media for the best growth and sporulation. Different kinds of colony structure components depending on the media were studied. As result of the researches conducted, it was revealed that oat and straw agars were the best media for the stable obtaining of high quality inoculum of Pyrenophora tritici-repentis agent.

The results of the researches conducted under the soil climatic conditions of Grodno region on the study of the features of growth, development and yield formation of japanese millet and buckwheat depending on plant treatment by a rape meal product are presented in article. The researches allow to established that the use of the rape meal product increased the japanese millet and buckwheat grain yield by 0.3 and 0.11 t/ha, respectively, in comparison with the control, and the coefficient of energy efficiency increased by 0.48 and 1.0, respectively.

On the sod-podzolic sandy loam soils of the central part of Belarus, application of fungicides Pictor, SC (0.4 l/ha) and Prosaro, EC (0.6 l/ha) on spring rape in the phase of the middle of flowering provides biological efficiency in Alternaria and Sclerotinia diseases from 77.0 to 83.1% on average over the studied genotypes which provides yield increase by 0.41 and 0.57 t/ha or 19.7 and 16.8% as compared to the control. Such fungicides as Colosal Pro, ME (0.5 l/ha) and Caramba, EC (0.8 l/ha) saved the yield by 0.27 and 0.26 t/ha or 11.6 and 11.2% as compared to the control. All the studied fungicides promote fat content increase in the oilseeds by 0.7-1.7 absolute percentage points.

The researches allow to establish that the use of such fungicides as Pictor SC (0.5 l/ha), Prosaro EC (0.8 l/ha), Amistar Xtra SC (1.0 l/ha), and Colosal EC (1.0 l/ha) in the middle of winter rape flowering provided biological efficiency in the control of Sclerotinia (from 70.0 to 81.3%) and Alternaria (from 69.5 to 75.4%) diseases on average over the studied genotypes. The saved yield of the crop over three genotypes was 0.4-0.63 t/ha or 10.6-16.8% depending on the fungicide.

The results of the influence of salt stress in vivo on miscanthus biochemical parameters in a greenhouse experiment are presented. An increase in the concentration of chloride-sulfate salts in the soil up to 1-2% causes the increased enzyme activity of catalase and decreases the synthesis of “a” and “b” chlorophylls. These indicators can be used as a test-assessment for the selection of miscanthus for tolerance to soil salinity.

It was established that buckwheat competitiveness towards weeds did not depended on plant morphotype but on the special characteristics of a given cultivated variety. Herbicides used for the destruction of dicotyledonous weeds increased grain yield in diploid buckwheat indeterminate varieties in a greater extent than in determinate varieties. When on buckwheat crops graminicide Fusilade Forte was used after the preceding herbicide application for the destruction of dicotyledonous weeds, the range of the used pre-emergence products was taken into account, and on diploid buckwheat crops, the plant morphotype of the cultivated variety as well.

The research results of the study of weed species composition depending on the sowing terms of different millet varieties are presented in the paper. It has been established that small seed millet variety Galinka destroys weeds more successfully than large seed variety Druzhba 2. June sowing (2-nd ten-day period) reduces not only the number of most dicotyledonous weeds which can be controlled chemically but also such monocotyledonous weed as barnyard grass destruction of which is difficult enough; that is why millet sowing terms can be deemed as one of the agrotechnical weed control methods.

The analysis of field grass growing is presented in the article. The resources for fodder production increase due to the improvement of perennial grasses structure are shown. It is noted that the productivity of red clover, alfalfa, eastern galega reaches 0.1 t/ha and higher. The joining of leguminous-grass mixtures of annual grasses with postcut crops provides more than 0.1 t/ha feed units. Sweet sorghum provides the productivity equaled to 1.15-1.2 t/ha feed units.

The analysis of the productivity of drought-tolerant fodder crops in the southern part of the Republic of Belarus is presented in the article. The assessment of the economic efficiency of sweet sorghum cultivation under different usage patterns was carried out.

Sweet sorghum productivity using different sowing terms, rates and methods is analyzed. It has been revealed that the optimum sowing rate for sweet sorghum is 0.4 million seeds per ha. According to productivity parameters, a wide-row sowing method is better than row sowing one at all the studied sowing rates. The optimum sowing term of sweet sorghum in the southern part of Belarus is the third ten-day period of April-the first ten-day period of May.

Research results on chemical composition and nutritional value of barley and maize, economic efficiency of maize grain growing as compared to barley and a postharvest crop are presented in the article. Superiority of maize over barley and oil radish in fodder unit yield and profitability is shown. The maize profitability was 53.2-84.1%, whereas, in the cultivation of grain-fodder barley with postharvest oil radish, it was from -9.9 to +30.7%. The best economic indices on maize and barley are provided by the conservation of wet grain or grain and cob mixture into polymeric tubing.

The comparative evaluation of chemical composition and nutritive value of maize hybrids is given. The correlation analysis of the data obtained for two years was carried out. The analysis of the interinfluence of yield and some indices of the chemical composition and nutritive value of leaves and stalks, grain and plants of maize in whole was done.

The results of two-year researches on the study of the responsiveness of Belarussian (Polessky 195) and German (Ricardinho) maize hybrids to the application of postemergent or soil herbicides, different rates of mineral nitrogen (90 and 150 kg/ha), use of organic fertilizers in maize recultivation are presented in the article. The effect of these factors on the size of costs, net profit, profitability and fodder unit cost price is shown. It has been established that the highest net profit in both hybrids is provided using soil herbicide Primextra Gold at the rate of 3.5 l/ha annually, 90 kg/ha of nitrogen, and 50 t/ha of organic fertilizers in the first year.

The analysis of perennial grasses structure in Belarus is presented in the paper. The structure optimization will provide the increase of perennial grasses acreage on the arable lands from 771 thousand ha to 1034 thousand ha or by 1.34 times, and the increase of herbage gross yield up to 28.99 million tons or by 1.45 times due to the acreage extension of leguminous grasses on the soils with light mechanical composition and high pH where alfalfa and red clover do not grow or form very low productivity. The increase of the herbage gross yields of perennial grasses up to 17.8 million tons or by 2.1 times will be due to the acreage extension of leguminous grasses up to 549 thousand ha. However, crude protein gross yield will increase from 632.9 to 934.2 thousand tons or by 1.5 times due to higher crude protein yield of leguminous grasses stands (from 275.1 to 575.6 thousand tons or by 2.1 times).

Intergeneric hybrid of perennial ryegrass (Lolium perenne) and meadow fescue (Festuca pratense) cv. Meteor has been developed. On sandy loam soils, the hybrid forms 6-7 grazing cycles when using for pastures or 4 hay cuts when using for haymaking. Winter hardiness is at the level of 4.5; herbage yield over the vegetation period is from 4.3 in dry years up to 6.7 t/ha in years with long-term average annual precipitation; crude protein content is 22%; total exchangeable energy is 1.7 MJ/kg DM in the period of the sward readiness for grazing.

The results of the use of bacterial product Kleverin on white clover swards are presented in the article. It was established that in the first year of use, treatment of white clover seeds with product Kleverin promotes plant growth and development (emergency of the second ternate leaf 2 days earlier; increase of plant saving by 14-15%). The application of the product on one-year white clover swards at the phase of one-two ternate leaves contributes to the plant growth and accumulation of overground biomass by 12.6% in comparison with the standard and by 12.9% when Kleverin was used on the seeds.

Methods of marker-assistant triticale breeding for resistance to leaf, stem, and stripe rust was developed. The following breeding accessions containing resistance genes were selected: Lr10, Lr25, Lr2, Yr9, Sr31, Sr2, Yr5, and Yr10. The following winter triticale accessions with a complex of genes were isolated: 17268, 19946 (Lr26, Sr31, Yr5, Yr9, and Yr10), 19408 (Lr26, Sr31, Yr9, and Yr10). The following resistance genes were not revealed in the breeding triticale accessions: Lr1, Lr9, Lr12, Lr19/Sr25, Lr20/Sr15, Lr21, Lr24/Sr24, Lr28, Lr34/Yr18, Lr35/Sr39, Lr37/Sr38/Yr17, Lr47, Sr22, Sr26, Sr36, Sr40, Sr44, Sr45, Sr50, Sr1RS^Amigo, and Yr26.

In the article, the basic results of self-fertile winter rye lines development with the use of different methods are stated. The method of self-fertility genes introduction into rye populations, the method of inbred lines development with the use of F1 heterosis hybrids are described. The necessity of working out of anther technology culture in vitro for the development of rye double haploids is noted. The practical use of the developed inbred lines in rye breeding for heterosis is described.

The study of callus genesis in in vitro culture of immature inflorescences of winter wheat was conducted. It was established that there was a highly significant positive interrelationship between ear size and callus size: r=0.46 (Т-62) – r=0.78 (Fenda). There was a varietal response to ear length for the obtaining of regenerants with the maximum callus size. The optimum size of an immature ear providing maximum and stable number of well-developed, highly morphogenic calli was in the range of 1.9-2.3 cm.

The study of a winter triticale collection allowed to isolate the sources of agronomic characters with the yield higher than 7.5 t/ha, plant height less than 100 cm, high grain number per ear (more than 47.0 grains), very high thousand-kernel weight (higher than 55.0 g) for their purposeful use in breeding.

Baking and fodder qualities of winter rye grain, content of antinutritional components, problems of grain use in human food and animal nutrition are analyzed in the article. Main directions of breeding towards increasing of nutrient and fodder value of winter rye grain are shown.

Two-year results of the evaluation of spring wheat collection for the resistance to Fusarium head blight are presented. Main criteria for the complete evaluation of the resistance to the given disease were revealed. 11 accessions resistant Fusarium head blight and 5 accessions resistant to Fusarium grain blight were isolated. A mathematical model for the influence of Fusarium grain blight on the laboratory germination of spring wheat was developed.

The results of three-year researches on winter soft wheat accessions in the competitive variety testing are presented and analyzed in the article. It has been established that by a complex of economic and biological characters, the accessions with numbers 0560, 0311/1, 0311/2 were isolated. They can be transferred to the State Variety Testing of the Republic of Belarus.

The research results of collection alfalfa accessions of different origin, data on the number of the existing alfalfa species in the world as well as the information on those species which are used in arable farming are presented in the paper. The meaning of the conducted researches for the  breeding process is shown. The accessions with agronomic characters and interesting for alfalfa breeding on the territory of the Republic of Belarus have been isolated.

108 corn inbred lines were tested in laboratory and field conditions; 7 lines which had high level of cold tolerance were selected. Positive correlation on an average level was revealed between germination, seedling length and yield, average for 2 years – +0.58. Positive correlation on a high level was revealed between the radicle length and yield +0.79. Inbred lines FV 243, UCH 37, HLG 1238, Co 255, Ak 135 and HLG 1203 were recommended for using as sources of cold tolerance.

Breeding research results on blue lupine used for grain and other purposes are presented. In competitive variety trials, the accessions with the highest productivity of seeds and dry matter, which exceeded the standard varieties, were isolated. Among the isolated accessions, two of them were selected for transferring to the State Variety Testing Commission for studying in 2016.

Study results of millet collection accessions of different ecological and geographical origin from VIR world collection by basic plant productivity elements for the revealing of sources for further use in the breeding process are presented in the paper.

Evaluation results of the initial material of Russian and Ukrainian origin in comparison with the Belarusian standards are presented. Significant differences between the samples depending on their origin were found. In whole, the foreign variety samples were inferior to the Belarusian standards in the productivity of flax stock and long fibre but exceeded them in the seed yield, particularly the samples of Ukrainian breeding.