Research results on the study of the effect of sowing terms on the yield of winter triticale varieties taking into account their morphological features and environmental response are presented in the article.

It was established that the yield of the studied varieties ranged from 5,6 to 8,4 t/ha on average for the research years. On average for three research years, the lowest yield (6,7 t/ha) was obtained when winter triticale sowing was conducted on August, 30; the highest yield – 7,7 and 7,8 t/ha – was achieved at the second (September, 10) and the third (September, 20) sowing terms, respectively.

The assessment of the sanitary condition of soils near livestock complexes and poultry farms was carried out. The level of total microbial contamination and thermophiles increased to a greater extent in the soils in the initial period after the introduction of poultry manure and pig effluents (by 75–464 % and 57–108 %); according to the coli­titer (0,001) and perfringens­titer (0,0001), the soils are assessed as «dangerous, polluted». Three months or more after their application, a decrease in the total microbial number and thermophiles was noted; according to the values of the coli­ and perfringens­titers of the soil in the category «relatively safe, slightly polluted». The soils on which very high doses of liquid cattle manure were applied for a long time had low values for coli­titer (0,006) and perfringens­titer (0,0001) – «dangerous, polluted». According to the helminthological analysis­the soil is clean (no helminth eggs).

The introduction of a carbamide­ammonia mixture to­ gether with trace elements of copper and manganese and humic­based preparations Gumidar and Gumistim contribut­ ed to an increase in winter wheat grain yield by 0,5–5,9 c/ha, gluten content – 4,7–4,6 %, profitability level – 10,7–3,1 per­ centage points, bioenergetic coefficient – 1,4–1,9 units com­ pared with the control variant. The best options are where the carbamide­ammonia mixture was introduced together with copper and manganese, and humic­based preparations Gu­ midar and Gumistim against the background of N25P50K110, since the yield of winter wheat was in the range of 71,3– 71,9 c/ha. At the same time, the level of profitability and the bioenergy coefficient amounted to 64,6–62,3 % and 4,8 units, respectively.

The results of researches on studying chocolate spot harmfulness as the most spread disease in fodder bean crops under conditions of the Republic of Belarus are presented in the article. It is revealed that the level of the disease development from which a significant decrease in the mass of 1000 seeds is possible makes 5,08 %, grain yield – 2,14 %. The potential grain yield losses when plants are affected by chocolate spot on the 4­th point can reach 68,7–72,6 %.

The results of studying the incidence and population structure of viral potato diseases agents in the Republic of Belarus are presented. It is found that among the symptoms of viral diseases in potato plantings, mosaic rolling, curling, ordinary mosaic and mottledness are the most common. Streak and rugose mosaics are found singularly In the structure of populations of viral diseases agents in the republic, the leading position is occupied by viruses M and S, viruses Y and X are less common. Viruses A and L have local distribution.

The research was carried out in 2018–2021 on winter cereal crops (wheat, triticale, rye, barley). It was determined a significant variation of species biodiversity depending on region, crop and growing season. Fusarium equiseti, F. avenaceum, F. culmorum, F. oxysporum prevailed on wheat, triticale and rye whereas F. oxysporum, F. solani, F. avenaceum dominated on barley.

The results of bulb onion affection during vegetation and storage period (bulb onion), seed bulbs and seeds are presented. The specific phytopathogens composition, affecting growing plants and bulbs during storage is shown. In seeds the generic belonging of fungi is identified.

In the article the results of researches on biological and economic efficiency of herbicides in winter garlic plantations cultivated under drip irrigation conditions on sod­podzolic sandy soil in Belarus are presented. It is determined that after the application of herbicides Boxer, EC – 1,5 l/ha + Goal 2E, EC – 0,2 l/ha, Starane premium 330, EC – 1 l/ha, Basagran M, WS – 0,2 l/ha + Piramin turbo, SC – 0,4 l/ha, Arcade, EC – 3 l/ha at the height of winter garlic 10 cm in spring, the total kill of weed plants has made 87,8–83,0 %, for this, the annual dicotyledonous weed plants have killed for 95–100 % and the garlic bulbs yield and its quality have for certain increased.

The state of the protein complex in pea microgreens at 8, 10, 12, 14, and 16 ­hour LED lighting times are discussed. It was shown that this factor does not significantly affect the total accumulation of proteins in microgreens against the background of significant changes in the rates of biosynthe­ sis of individual components in the protein complex. It was shown that 10­hour exposure ensured the maximum accumu­ lation of albumin, globulins and glutelins in the experiment, while 16­hour exposure, as well as 12­hour exposure, taken as a control – prolamins. The most favorable conditions for protein biosynthesis were provided by 14 and, to a greater extent, 10­hours of LED illumination, while the least favora­ ble conditions were provided by 8 and especially 16­ hours.