The article based on the results of its own research and summarize published data provides information about the dependence of the nitrate content of the various factors. This indicates that the accumulation of these compounds in plants is greatly enhanced due to the imbalance of power elements. Under them there using to feed perennial grasses slow-acting nitrogen fertilizer. Conversely, on the background of ammonium nitrate, especially increasing content of nitrates in plants. It is shown here and the significant influence of weather conditions. Installed as the daily dynamics of nitrate content: a minimum of the number occurs in harvesting herbs in the evening.

   We studied the effect of gibberellin (gibberellic acid, GK3) on morphogenesis, formation of the leaf apparatus and crop yield of tomato sort Bobcat. It was found that under the influence of the drug increased the number of leaves and their weight on the plant, formed a powerful leaf mesostructure, increased figures of photosynthetic activity of plants treated with the drug. As a result of these changes significantly increased crop yield.

   The results of monitoring of diseases severity complex in grain crops indicating the incidence increase of new under conditions of the Republic of Belarus diseases are presented, such as yellow rust (Puccinia striiformis), pirenophorosis (Pyrenophora triticirepentis), dwarf leaf rust of barley (Puccinia hordei). Snow mould (Typhula incarnata), root rot (Fusarium graminearum), Septoria leaf blotch (Septoria tritici) and ear spot disease (Septoria nodorum), Fusarium head blight (Fusarium culmorum), powdery mildew (Blumeria graminis), rhynchosporiosis (Rhynchosporium secalis), helminthosporiosis (Bipolaris sorokiniana =Cochliobolus sativus) of barley leaf apparatus are still wide-spread and harmful.

   The results of researches have shown that turnip moth (Agrotis segetum Den.&Schiff.) is a noxious polyphagous pest in different regions of Brest and Gomel districts of the Republic of Belarus. In 2013 and 2015 high number focuses (from 15 to 624 indiv./m² and winter grain crops severity are determined what has caused the essential yield losses. In 2016 the researches on studying the attractiveness of turnip moth sex pheromone, synthesized at Stock-Holding Company «Shchelkоvo Agrokhim» were carried out for the first time based on which the seasonal number dynamics and periods of the first and second generations of the butterflies flight in the fields of main agricultural crops was determined. For the vegetation period turnip moth number of the first generation was higher than the second generation what was connected with different temperature conditions and rainfall. High attractiveness of the first generation turnip moth synthetic pheromone was marked in sugar beet crops – 2,5–2,9 indiv./trap- day, corn – 2,3 indiv./trap – day and potato – 2,3 indiv./trap – day; the second generation – in the fields with wind fallen rape and oat stubble, in sugar beet crops (1,1–1,6 indiv./trap-day).

   Under small-plot and farming trial conditions a study of herbicide Sancor, WDG (rimsulfuron, 4,3 % + nicosulfuron, 12 % + mezotrion, 40 %) influence on weed infestation of corn crops at 2–6 crop leaves stage application is done. Herbicide Sancor, WDG (0,25; 0,28; 0,3 kg/ha) effectively suppresses grass and dicotyledonous weeds, their kill in 2013 has made 97,5–98,4 %. As a result of weed infestation decrease corn grain preserved yield has made – 50,0–71,6 cwt/ha.

   The biological efficiency of the herbicide Graider, WDG (imazapyr, 250 g/l) for Sosnowsky's hogweed(Heracleum sosnowskyi Manden.) control is studied. The maximum efficiency is reached by herbicide application before spring aftergrowing or at the plant height up to 30 cm (97,7 % and 83,8 % kill), by herbicide application at later periods of time, the efficiency is decreased to 74,9 %. It is determined that Sosnowsky's hogweed number and vegetative weight decrease in 30 days after treatment has made 65,2–86,9 % and 92, 5–97,5 %; in 60 days – 97,3–99,0 % by number and 99,5–99,9 % by weight. By herbicide Grader, WDG application also the other plant phytocoenosis components are killed.

   In the article the results of search results on determining the rates and periods of the herbicide Pulsar SL, AS (imаzamox, 40 g/l) in blue lupine crops are presented. Based on the research results rather high Pulsar SL, AS (0,75–1,0 l/ha) efficiency by pre-emergent application is determined. Post-emergent Pulsar SL application in lupine crops at 2–4 and 4–6 leaves is not recommended as a result of phytotoxic action on the crop.

   Lupine aphid (Macrosiphum albifrons Essig) is alien to the European fauna and native to North America aphid species. For the first time the species has been registered in Belarus in 2010, further it spreads all over the country. Lupine country may become an economically significant pest and a vector of viral diseases of lupine.

   During 2013–2015, there were examined proso millet crops and their phytosanitary condition. It was found that the most widespread and harmful diseases are brown leaf spot, piriculariose and root rot. The effectiveness of treatment of proso millet seeds for fungal pathogens was examined. It was found that the disinfectant Jagger Plus in a dose of 0,25 l/t ensures technical effectiveness. It provides the protection of crop yield at the level of 0,42 t/ha.

   In this article, the results of studies on the influence of the level of clogging of rice crops on the productivity are outlined. A reduction in the productivity during the period of competition of existing weeds was established, as well as the correlation between the duration of clogging, the mass of weeds and the productivity of rice plants was defined.

   In 2008–2009 in the belarusian Polesie conditions there was widespread powdery mildew damage of pea crops. The appearance and development of the disease is promoted by the alternation of hot weather and a moderate amount of precipitation. Under favorable weather conditions, powdery mildew appears during the flowering period or the beginning of the bean formation. During heavy rains, a part of the conidia of the pathogen is washed away, as a result of which the infectious load decreases. In the еpiphytotic development of powdery mildew, the pea yield is reduced by 57,3–76,4 %, with moderate – by 19,2–38,2 %.

   The article presents the main results of the research growing potatoes on the principles of organic farming. The cultivation of potatoes for ecologized technology using biological agents provided marketable tuber yield variety: Lileya – 28,8 t/ha, Skarb – 21,1 t/ha, Ragneda – 27,7 t/ha. Potato varieties Belarusian selection are highly resistant to late blight and can be recommended for cultivation. For getting of ecologically pure products definitely the cultivation of varieties (Lileya, Ragneda, Vektar, Atlant, Zdabytak, Accent, Rubin) with the highest long-term resistance to late blight and other harmful diseases.

   Research new varieties of green beans Dubrovenskaya and Chyzhovenka that are included in the State Register of varieties and trees and shrubs of the Republic of Belarus. Varieties have a complex of economically valuable sings and are recommended for home-farm cultivation.

   It has been studied the influence of spatial distribution of brussels sprouts plants on the productivity of its varieties of different maturity groups in the field experiment. It has been investigated the depending of biometric indicators of brussels sprouts varieties on the density of host plants. It is established that the scheme of placement of plants with different density, significantly affect the amount of bits generated per plant, their weight and overall yields.

   A well-known scientist in the field of crop production, corresponding member of the National Academy of Sciences of Belarus,
Doctor of Agricultural Sciences, Professor Fedor Ivanovich Privalov celebrated his anniversary on February 10.

   February 15, 2017 the staff of the NAS Scientific and Practical Center Agriculture experts of Belarus, scientists and, first of all, agrarians - scientists and practitioners – noted 110th anniversary of the birth of an outstanding scientist-breeder, a distinguished scientist of the BSSR, a Hero Socialist Labor, laureate State Prize, Professor Nikolai Dmitrievich Mukhin. This man has made a major contribution to the development of domestic and world agricultural science and practice.