The article presents the results of studying the effect of rape straw and methods of basic tillage on the economic efficiency of the cultivation of various varieties of winter wheat. It was established that when placed in the crop rotation of winter wheat after rape to reduce production costs, optimize the timing of the main tillage and sowing of this crop, it is advisable to replace plowing with chisel pans, regardless of the use of precursor straw. When using rapeseed straw for fertilizer, it is necessary to sow the varieties of Augustine and Mroy, which to a lesser extent reduce the yield under the influence of cruciferous predecessor straw, than the variety Elegy.

High agronomic and economic efficiency of fertilizers and growth regulators in barley crops has been established. The highest grain yield in the early maturing variety Bat’ka and mid-late variety Yakub was noted in the variant N₈₀P₇₀K₁₂₀ + N_{40 carb.} + MicroStim-Copper L, which was 7,0 and 7,25 t/ha respectively. In the same version of the experiment, the highest value of the increase (438,9 and 475,5 USD/ha) and net income (150,0 and 174,7 USD/ha) were noted.

The maximum profitability of barley varieties Bat’ka and Yakub was observed in the variant with the use of Legum Copper on the background of N₉₀P₆₀K₉₀ (61,2 and 67,6 % respectively).

The use of microfertilizers of the Belarusian production of MicroStim-Copper L and Legum Copper on the effect on the yield of barley grain was not inferior to the Polish microfertilizer Adob Copper, and they exceeded it in economic efficiency and can be used for import substitution.

The results of research of retardants’ use effectiveness in the process of durum spring wheat of Rozaliya and Iride kind sowing are presented. It is established that reiterated use of retardants’ ensures better protection.

In the result of monitoring winter wheat crops the phytosanitary situation was estimated and structural changes were detected in the conditions of Belarus. On the basis of data obtained species composition of harmful organisms was specified, thresholds of harmfulness were calculated and yield losses were predicted.

The efficacy results of fungicidal, insecticidal, combined insecticidal and fungicidal seed dressers, fungicides, insecticides and herbicides which are using during winter wheat vegetation to reduce main diseases harmfulness, number of phytophages and damaged plants because of them and reduce weeds. There were substantiated integrated thresholds of using of combined plant protection products that contain different compounds. It is determined that using of products under investigation provides obtaining of 12,2 to 17,4 % of yield.

The European corn borer is a noxious corn pest in Belarus. Initially, the phytophage has developed in large number on permanent corn crops cultivated in the Southern and New agroclimatic zones, where plants damage has ranged from 30.2 to 90.0 %. Since 2015, its range has expanded, high population focuses have been formed in the central regions. The phenology of the European corn borer is presented in different agro-climatic conditions. The agrotechnical measures significantly decreasing the insect’s harmfulness have been recommended. The insecticides efficiency at depressed and massive pest development has been evaluated. An assortment of insecticides has been formed and the economic feasibility of their use in corn crops by cultivation for grain, seeds and green mass has been substantiated.

In the article the results of researches on the evaluation of a phytosanitary state of fodder bean crops under conditions of the Republic of Belarus are presented. The dominant disease agents, pests and weed plants by agroclimatic zones of the crop cultivation are determined.

The application of a system CONVISO® SMART for sugar beet crops protection against weed plants, based on sugar beet hybrids use resistant to acetolactate synthesis inhibitor herbicides (ALS), in a combination with the herbicide Conviso 1, MD (tienkarbazon-methyl, 30 g/l + foramsulfuron, 50 g/l), allows to keep the crops free of weeds up to harvesting; does not render the phytotoxic action on SMART-hybrids of the crop and technological root crop quality; for raising the total efficiency it is used with the SAS Mero. This system is the only effective against volunteer sugar beet, however, it does not cancel the application of glyphosate-containing herbicides against perennial weed plants in the previous year autumn.

Based on many years researches, it has been found that in corn crops, bird cherry (Rhopalosiphum padi L.) and English grain (Sitobion avenae F.) aphids are wide-spread. With the average daily air temperature of + 16 ... + 20 °C and relative air humidity of 65–80 %, in July – August there is a massive development and high severity of grass aphids. To substantiate the expediency of carrying out the protective measures against aphids, it is necessary to monitor ones at 8–10 leaves stage of corn. With the entomophage : pest ratio of 1 : 15, the pest populations number is reduced by coccinellids (fam. Coccinellidae) and common lacewings (fam. Chrysopidae). According to the research results, it is found that insecticides application against aphids and The European corn borer is economically expedient when their threshold number is increased.

Under small-plot experimental conditions the herbicide Camelot, SE (C-metolochlor, 312,5 g/l + terbuthylazine, 187,5 g/l) influence on corn crops weed infestation by application after sowing before seedlings emergence or at 2–3 leaves of the crop is studied. The herbicide Camelot, SE (3,0–4,0 l/ha) effectively suppressed annual grass and dicotyledonous weeds. In 2014 the biological efficiency has made 99,7–100 % by pre-emergent application, 97,2–100 % – at 2–3 leaves stage application; in 2015 – 97,7–100 % and 98,0–100 % accordingly.

As a result of conducted in 2017–2018 trials it has been determined that the application of preparations Rofatox, G – 30 g/m² and Grizly, G – 20 g/10 m² into the holes when planting tomato seedlings in the open ground reduces the plant damage by mole cricket for 86,9–95,6 %. The study of the insecticide Rofatox effect, put into the planting holes during potato planting, on tubers damage by imago and larvae of Gryllotalpa gryllotalpa has shown that this technique reduces potato tubers damage by the phytophage 2,9–3,2 times in comparison with the control.

Results of studies of the extent of damage to winter rye varieties by the causative agent of septoria of the leaves - Septoria tritici Rob. et Desm. and Stagonospora nodorum (Berk.) E. Castell. & Germano its harmfulness is determined. It was established that the development of the pathogen depended on the genotype of the host plants and the weather conditions of the growing season of the culture. The yield losses that accounted for 5,2 % of the susceptible variety Dozor with the development of the disease up to 10 % were investigated, and for the excess lesions up to 30 % – increased to 10,4 %. On a stable winter rye variety Siverske, the development of Septoria did not exceed 10 %, and the yield loss did not exceed – 1,5 %.

The paper presents the results of studies on the effect of humic fertilizers (Biovermtehno, 2,0 l/ha; Bioplant flora, 1,5 l/ha; Ecogum complex, 1,0 l/ha) obtained from natural raw materials using modern microbiological technologies, on yield and quality of flax products. The maximum yield was obtained by double processing of sowing with humic fertilizers in the “herringbone” phases → budding, which ensured for 2016–2018 years an average increase in seed of 0,7–0,9, trusts of 2,4–2,8, total fiber of 1,6–1,9 ce/hа, and long fiber of 1,0–1,3 ce/hа, improvement of fiber quality indicators: handful length by 1,9–2,4 %, flexibility by 7,6–10,1 %, breaking load by 13,3–19,0 %.

The article presents the results longstanding research of the effect of doses of mineral fertilizers on the growth and development of plants, the yield of seeds and the structure of hybrid seeds of white cabbage. The fractional composition and sowing qualities of seeds are also included.

Garlic as a cultural plant propagates a vegetative way. Most sorts of garlic characterized limit nature of the natural habitat, and at transference of them in other soil-climatic terms, sorts have considerable changes of morphological and biological signs, that often results in the decline of amount and quality of harvest of bulbs. Therefore plant-breeding work with a garlic is first of all sent to expansion and perfection of methods of creation of feedstock an experimental way. One of priority plant-breeding work assignments is creation of sorts with high maintenance of sugar, ascorbic acid and other bioactive substances. During the conducted researches, at the study of biochemical indexes, at sorts distinctions are educed between sorts on maintenance a dry substance 1,2 time, to the sum of sugar – 1,51 and ascorbic acid 1,5 time.

On the average for years researches of sort of garlic winter-annual Odincowski Jbileyny, Replikant, Lubasha, Pamati Nowisckowa, Junior, Union were characterized high maintenance of quality indexes and can be recommended both for a commodity production and for further plant-breeding work in other OF ecological and geographical factors.