Search

Primary Trans Chromosomal Tritipyrum (PTCT) amphiploid is a new cereal grown in saline soil and brackish water for grain and forage production. We evaluated the tolerance to seed deterioration in 13 promising PTCT lines, assessing accelerated aging (AA) tests by using AA boxes with 100% relative humidity at 40 °C for 72 h. The (Ma/b)(Cr/b)F4 and (St/b)(Cr/b)F4) PTCT lines, more sensitive to seed aging, were primed with NaCl, Salicylic Acid (SA), and Polyethylene Glycol (PEG) to increase the seed vigor of artificially aged seeds. Germination and emergence traits, biochemical parameters, and chromosomal abnormalities induced by artificial aging were measured in deteriorated and not-deteriorated seeds. The highest reduction percentages related to seed vigor were observed in (Ka/b)(Cr/b)F2 (34.52) and La(4B,4D)/b (28.15) lines, while the lowest was found in (Ma/b)(Cr/b)F4 (7.65) and (St/b)(Cr/b)F4 (7.46) lines. Seed aging also increases electrolytes, potassium, and protein leakages. Chromosomal abnormalities are caused by seed aging that interferes with chromosome behaviors during cell division. Seed priming on aged seeds revealed an increase in the germination percentage (GP) with PEG treatment, while the priming by SA showed an increase in seedling traits, such as the seedling length (SL2). In conclusion, we highlighted the potential use of different PTCT lines and the effective use of seed priming on deteriorated seed to enhance seed viability and seedling vigor as a useful tool for sustainable agriculture.

In recent decades, cereal agriculture across main producing areas in Spain has progressively adopted direct sowing, associated with an increased use of herbicides in pre-sowing. Weedy species from genus Avena have been observed after the application of glyphosate in wheat. Here, Avena fatua (two accessions), Avena byzantina and Avena sterilis subsp. sterilis, one accession each, were taxonomically characterized by a biometric study. Dose-response trials confirmed that one A. fatua accession evolved to resistance, because it was four times more resistant (R) than the others, ascribed as susceptible (S). In addition, based on LD50, A. byzantina and A. sterilis had low susceptibility to glyphosate, with 604 and 458 g ae ha−1. Shikimic acid accumulation was able to discriminate between high susceptible (A. fatua (S)), low susceptible (A. byzantina and A. sterilis), and low resistant (A. fatua (R)) populations. On the other hand, the study revealed that A. fatua (R), A. byzantina and A. sterilis had low foliar uptake and decreased movement of glyphosate. In addition, the metabolism study showed less metabolite accumulation in A. byzantina and A. fatua (S). However, at 96 h after glyphosate application, A. fatua (R) and A. sterilis were able to convert more than 30% of glyphosate to aminomethylphosphonic acid (AMPA) and sarcosine. Enzyme basal activity and I50 values predicted high affinity between the herbicide and the target enzyme for all accessions, thus indicating that a target-site (TS) mechanism is probably not involved in the differences in glyphosate susceptibility. In closing, non-target site (NTS) mechanisms could participate both in A. fatua R to glyphosate, and low susceptibility in A. byzantina and A. sterilis from Spain., This research was funded by Asociación de Agroquímicos y Medio Ambiente (Spain). Joel Torra acknowledges support from the Spanish Ministry of Science, Innovation and Universities (grant Ramon y Cajal RYC2018-023866-I).

В статье рассматриваются вопросы полученных результатов опытов и мнения ученых по исследованию действий микробиологических удобрений и препаратов на урожайность чечевицы. Рассматриваются действие микробиологических удобрений «Азотовит» и «Фосфатовит» при обработке в фазу ветвления на продуктивность и качество чечевицы; эффективность предпосевной обработки семян микробиологическим препаратом «Экстрасол-55» и комплексного микробиологического удобрения (КМУ) при почвенной инокуляции на чечевице., The article deals with the issues of the obtained results of experiments and the opinions of scientists on the study of the effects of microbiological fertilizers and preparations on the yield of lentils. The effect of microbiological fertilizers "Azotovit" and "Phosphatovit" during processing in the branching phase on the productivity and quality of lentils; the effectiveness of pre-sowing seed treatment with microbiological preparation "Extrasol-55" and complex microbiological fertilizer (CMU) during soil inoculation on lentils are considered.

Context: Sorghum is a hosting plant of Melanaphis sacchari/sorghi. The control measures against the insect include the treatment of seeds. However, evaluation of the effect of insecticides on insect populations and the agronomic variables of the crop, are needed. Aim: To evaluate the influence of insecticides clothianidin, thiamethoxan, and imidacloprid during the treatment of hybrid 85 P15 (Pioneer®) seeds on the agronomic variables of the crop and infestation with M. sacchari/sorghi. Methods: The experiment was conducted in the School of Higher Studies in Xalostoc, Mexico, in 2018. Four doses of Poncho®, Cruiser® 5 FS, and Tools® TS in the treatment of hybrid 85 P15 (Pioneer®) seeds. A randomized block experimental design was applied, and the percentage of germination, M. sacchari/sorghi infestation, and agronomic parameters of the crop, were determined. Results: All the parameters achieved more than 90% of germination, which demonstrated that the products and doses did not affect this parameter. Likewise, no differences were observed in the treatments. The use of these insecticides in hybrid seeds had a little influence on aphid infestation. These treatments do not affect the content of chlorophyll, but other parameters, like Brix degree, and the fresh leaf weight were affected. Conclusions: The seed treatment does not reduce the percentage of germination of 85 P15 (Pioneer®) hybrids, a strong control was not achieved over infestation of aphids, but it did affect some agronomic variables; hence, evaluation of other hybrids is recommended.

The results of testing and evaluation of the capabilities of the multifunctional T-allAr-2.8H cultivator for determining the efficiency of pre-sowing, shallow cultivation of soil, intermediate cultivation of the half-soil, wrapping of the overgrowing furrows are presented in the article. Expert assessment of the quality of work allowed us to determine the nomenclature of criteria and their level.Research methods - field experiment, organoleptic observations, instrumental measurements, expert comparisons and evaluations T-allAr-2.8Н.Results. The formation of a rational fleet of machines for small and medium-sized farms, subject to the selection of short nomenclature of machines, taking into account their wide functionality, is a positive factor in minimizing investment for the release of their part for circulating needs of the farm. This result can be achieved by acquiring machines with advanced, relatively traditional, capabilities.Creativity of thinking of manufacturers of agricultural machinery, in particular, LLC PF POLIMASHPROEKT, their access to a modern elemental base, the potential of the machine park allowed to offer for this segment of market consumers cultivator T-allAr-2.8 with excellent opportunities.Field tests of the specified cultivator on different backgrounds confirmed its workability on pre-sowing, shallow tillage, intermediate cultivation of the half-steam, planting furrows. Expert assessment of the quality of work allowed determine the nomenclature of the criteria and their level achieved.Conclusions. The TallAr-2,8H multifunctional cultivator can be successfully used on various types of soil cultivation: pre-sowing, shallow, half-steam, finishing of accelerating furrows with excellent quality of work, thus the strong construction (even in the conditions of the increased dryness of the soil) allows to work without difficulty on such difficult backgrounds , as large dry blocks, which is facilitated by well-founded layout solutions and the choice of rational curved sections and quality of steel curved racks with a two-roller ring damper., В статье приведены результаты испытаний и оценки возможностей многофункционального культиватора T-allAr-2.8 для определения работоспособности на предпосевной и мелкой обработке почвы, промежуточной культивации полупара, заделке разгонных борозд. Экспертная оценка качества работы позволила определить номенклатуру критериев и их достигнутый уровень.Цель работы - исследование функциональных возможностей и экспертная оценка качества работы многофункционального культиватора T-allAr-2.8Н.Методы исследований - полевой эксперимент, органолептические наблюдения, инструментальные измерения, экспертного сравнения и оценки.Результаты. Формирование рационального парка машин для фермерских хозяйств малого и среднего размерного уровней, при условии отбора короткой номенклатуры машин с учетом их широких функциональных возможностей, является положительным фактором минимизации капиталовложений для высвобождения их части на оборотные нужды хозяйства. Такой результат может быть достигнут за счет приобретения машин с расширенными, относительно традиционных, возможностями.Креативность мышления производителей сельскохозяйственной техники, в частности4 ООО «ПФ ПОЛИМАШПРОЕКТ», их доступ к современной элементной базе, потенциал станочного парка позволили предложить для указанного сегмента потребителей рынка культиватор T-allAr-2.8 с отличными возможностями.Полевые испытания указанного культиватора на разных фонах подтвердили его работоспособность на предпосевной, мелкой обработках почвы, промежуточной культивации полупара, заделке растительных борозд. Экспертная оценка качества работы позволила определить номенклатуру критериев и их достигнутый уровень.Выводы. Многофункциональный культиватор TallAr-2,8Н может быть успешно использован на различных видах обработки почвы: предпосевной, мелкой, полупаровой, заделке разгонных борозд с отличным качеством работы, при этом прочная конструкция даже в условиях повышенной сухости почвы позволяет беспрепятственно работать на таких сложных фонах как большие пересохшие глыбы, чему способствуют обоснованные компоновочные решения и выбор рациональных по сечению и качеству стали криволинейных стоек с двухвитковым кольцевым демпфером., У статті наведені результати випробувань та оцінювання можливостей багатофункціонального культиватора T-allAr-2.8Н для визначення працездатності на передпосівному, мілкому обробітках ґрунту, проміжній культивації напівпару, загортанні рослинних борозен. Експертне оцінювання якості роботи дало змогу визначити номенклатуру критеріїв та їхній досягнутий рівень.Мета роботи – дослідження функційних можливостей та експертне оцінювання якості роботи багатофункціонального культиватора T-allAr-2.8Н.Методи досліджень – польовий експеримент, органолептичне спостереження, інструментальні виміри, експертне порівняння й оцінювання.Результати. Формування раціонального парку машин для фермерських господарств малого і середнього розмірного рівнів, за умови вибору короткої номенклатури машин з урахуванням їхніх широких функційних можливостей, є позитивним чинником мінімізації капіталовкладень для вивільнення їх частини на обігові потреби господарства. Такого результату можна досягнути, придбавши машини з розширеними проти традиційних можливостями. Креативність мислення виробників сільськогосподарської техніки, зокрема ПП «ВФ ПОЛІМАШПРОЕКТ», їх доступ до сучасної елементної бази, потенціал станкового парку дали змогу продукувати на вказаний сегмент споживачів ринку культиватор з відмінними можливостями.Польові випробування вказаного культиватора на різних фонах показали його працездатність на передпосівному, мілкому обробітках ґрунту, проміжній культивації напівпару, загортанні розгінних борозен. Експертне оцінювання якості роботи дало змогу визначити номенклатуру критеріїв та їхніх досягнутий рівень.Висновки. Багатофункціональний культиватор TallAr-2,8Н може бути успішно використаний на різних обробітках ґрунту: передпосівному, мілкому, напівпаровому, загортанні розгінних борозен з відмінною якістю роботи. До того ж міцна конструкція навіть в умовах підвищеної сухості ґрунту дає змогу безперешкодно працювати на таких складних фонах як великі пересохлі скиби, чому сприяють обґрунтовані компонувальні рішення та вибір раціональних за перерізом і якістю сталі криволінійних стійок з двовитковим кільцевим демпфером.

Introduction There are about 160 species in Brassica genus, which are mostly annuals and biennials. The plants in this genus have potential for fodder uses. The progress in plant breeding science has produced new crop varieties for oil and forage usages. Perko varieties are derived from crosses between tetraploid plants of winter rapeseed (Brassica napus L.Var. napus) and Chinese cabbage (Brassica campestris L. var. sensulato). The new plants are superior to their parents from various aspects. Buko varieties are new amphiploid plants obtained by crossing between tetraploid winter rapeseed, Chinese cabbage and turnips (Brassica campestris L. var. Rapa). Oilseed radish with scientific name (Raphanus sativus L.) is a genus of the Brassica and consumption, oil, green manure, feed and fodder (24). This plant in many countries, including Canada, is cultivated in gardens as cover crop. Oilseed radish grows fast in the cool seasons. Ramtil (Guizotia abyssinica) belongs to the Compositae family, Phasilia (Phaceli atanacetifolia L.) belongs to Boraginaceae family and clover is from Fabaceae family that is grown for feeding purposes. Materials and Methods A field experiment was conducted from 2011 to 2012 in the Karezan region of Ilam, Iran (42º33′N, 33º46′E) on a silty-clay with low organic carbon (1.26%) and slightly alkaline soil (pH=7.9). This site is characterized as temperate climate with 370 mm annual precipitation. The experiment was arranged in a split plot based on randomized complete block design with four replications. The main plots consisted of 6 pre-sowing plant treatments (control, Perko PVH, Buko, Clover and Oilseed radish and combination of three plants Ramtil, Phaselia andclover), and sub plots covered four N fertilizer rates including no fertilizer N (Control), 50% lower than recommended N rate, recommended N rate and 50% more than recommended N rate. Winter wheat (cv. Pishtaz) was sown on mid-November with the row spacing of 15 cm and a seeding rate of 200 kg ha-1. Soil samples were collected after harvest of each crop from 0 to 30 cm and 31 to 60 cm soil depths using a soil auger. Wheat grain yield (according to 14% moisture) obtained by harvesting the central area of 3 in 10 m in each plot. Yield components were determined from two randomly selected areas (2m2) within each plot. Plant samples collected at harvest were separated into grain and straw and oven-dried at 60˚C for 72hr. Biomass and grain sub samples analyzed for total N content using a micro-Kjeldahl digestion with sulfuric acid. The terminology of N efficiency parameters was considered according to Delogu et al, (11) and Lopez-Bellido & Lopez-Bellido, (22), Rahimizadeh et al. (30), Limon-Ortega et al. (20) methods. Results and Discussion The results showed that there were highly significant differences (P ≤ 0.01) in forage yield. There were also significant differences (P ≤ 0.05) in total dry weight, protein content and protein yield between treatments. Perko varieties produced higher fresh and dry matter yield with 69,586 (kg ha-1) and 7147 (kg ha-1), respectively compared to other varieties. Buko varieties showed greater protein percentage with 23.36 compared to the rest of the varieties. The highest and lowest grain yield, with 8345, and 4491 (kg ha-1) were obtained for Buko; wheat rotation and fallow, wheat rotation, respectively. The highest and lowest nitrogen uptake was obtained for Buko; wheat and clover, wheat rotation, respectively. The differences between the rotations were significant for various agronomic nitrogen efficiency. The rotation of oilseed radish and wheat showed greater nitrogen economic performance with 36.20 kg ha-1. By increasing nitrogen rate agronomic performance decreased with the exception in fallow- wheat. Physiological efficiency of nitrogen in fallow-wheat rotation was more than 39 (kg kg-1) of nitrogen. The maximum efficiency of nitrogen recovery was obtained for oilseed radish: wheat and Perko PVH; wheat rotations with 45% and 36%, respectively. The highest nitrogen harvest index was observed in Buko; wheat rotation: (86.5%), and Perko: wheat (85%) and the lowest nitrogen harvest index was in fallow; wheat (79.28%). Conclusions The results showed that Perko; wheat and Buko; wheat rotations due to the higher economic performance in the region were appropriate rotations and were recommended for the study area.

Herbal medicines are in great demand for preliminary health care due to their wide medicinal value, with no side effects. Since many species are used in the system of traditional medicine, scientists have great opportunities to develop appropriate packages of practices for their multiplication and conservation. Abrus precatorius is the native plant of India and used in many ways in the Indian Ayurvedic system of medicine. This seeds of the species is dormant due to hard seed coat. So the aim of the study is to remove seed dormancy and enhance germination capacity within a short period. To overcome the problem of dormancy, seeds were scarified by seed scarifier and sand paper and also treated with acid (H2SO4) and hot water just before sowing. 60-95% germination was achieved under different treatment conditions while the seeds without any treatment fail to germinate. The highest (95%) germination was observed just 12 days after sowing in seeds treated with concentrated H2SO4 for 120 minutes. 70-75% germination was achieved when the seeds were treated with acid for 105 and 135 minutes. Seeds treated with con. H2SO4 for 150, 90 and 60 minutes and also scarified by sand paper showed similar results with 60-65% germination. The seeds scarified by a mechanical scarifier and treated with hot water did not show more than 32.5% germination.

Приведено результати трьохрічних досліджень з використання регуляторів росту рослин та мікродобрива Квантум-зернові для підвищення урожайності насіння пшениці озимої і ячменю ярого. Встановлено найбільш ефективні з них за різних способів використання. Прораховано економічну ефективність застосування регуляторів росту рослин., Цель и задачи исследования. Целью работы было изучение влияния современных регуляторов роста растений и микроудобрения на семенную продуктивность, экономическую эффективность, получение дополнительного количества семян, главным при этом было ускоренное размножение семян новых сортов пшеницы озимой и ячменя ярового именно в семеноводческих посевах этих культур.Материалы и методи. Исследования проводили на полях лаборатории семеноводства и семеноведения ИР им. В. Я. Юрьева НААН на сортах озимой пшеницы Розкишна и Досконала и ячменя ярового Выклык и Парнас. Методы исследований – полевой и лабораторный.Предшественником пшеницы озимой был черный пар, а ячменя ярового – горох, сеять озимую пшеницу и ячмень начали от суперэлиты и до первой генерации в течение 2011–2013 годов, в оптимальные сроки, сплошным рядовым способом с нормой высева 4,5 млн. шт. на1 га, сеялкой СКС-10.Использовали регуляторы роста растений: Радостим, Регоплант, Стымпо, Деймос, Вымпел К, и микроудобрение Квантум-зерновые, протравитель Витавакс 200 ФФ, гербицид Гродил макси и минеральное удобрение Нитроаммофоска.Обсуждение результатов. Лучшим препаратом для предпосевной обработки семян и двойного применения на пшенице озимой сорта Роскошная является Стымпо (прибавка 0,29 т/га или 5 %). При выращивании сорта Досконала лучшими препаратами для обработки семян были Регоплант и Вымпел К (прибавка 0,22–0,23 т/га или 4 %), а для двойного применения Деймос и Вымпел К в сочетании с микроудобрением Квантум (прибавка 0,28 т/га или 5 %).Лучшим способом применения регуляторов роста растений и микроудобрений при выращивании семян ячменя ярового сорта Выклык является опрыскивание растений баковой смесью препаратов Регоплант и Квантум в фазу кущения, а также препаратами Регоплант или Квантум в фазу флагового листа (прибавка 0,23–0,31 т/га или 6–10 %), а для сорта Парнас опрыскивание растений баковой смесью препаратов Радостим и Квантум в фазу кущения, а также препаратами Радостим или Квантум в фазу флагового листа (прибавка 0,22–0,28 т/га или 6–8 %).Применение регуляторов роста растений и микроудобреня способствовало получению дополнительной прибыли по пшенице озимой: суперэлита на 575–2450 грн./га, элита на 209–422 грн./га, первая генерация на 294–551 грн./га, по ячменю яровому: суперэлита на 1610–3100 грн./га, элита на 522–1155 грн./га, первая генерация на 133–512 грн/га. А также способствовало получению дополнительного количества произведенных семян первой генерации пшеницы озимой в пределах от 586 т до 873 т и ячменя ярового от 83 т до 179 т.Выводы. Ежегодное применение современных регуляторов роста растений, микроудобрений и пестицидов в процессе размножения новых сортов, позволяет увеличить производство семян в каждом звене семеноводства с улучшением урожайных свойств, что является действенной мерой ускорения их внедрения в производство. Эффективность разработанных способов повышения семенной продуктивности пшеницы озимой и ячменя зависит от препарата и способа его применения., The aim and tasks of the study. The aim of this work was to study the impact of modern plant growth regulators and micronutrients on seed productivity, economic efficiency, get more number of seeds, mainly it was accelerated seed multiplication of new varieties of winter wheat and spring barley it is in seed crops these cultures.Material and methods. Research conducted in the fields of laboratory seedproduction and seedmaintenance Plant Production Institute named after V. Ya. Yuriev NAAS on the winter wheat varieties of Rozkishna and Doskonala and barley spring Wiklik and Parnas. Research methods field and laboratory.The predecessor of winter wheat – black couples and spring barley – peas, sow winter wheat and barley started from the super elite and up to the first generation in the period 2011–2013, in optimal time, continuous ordinary way with a seeding rate of 4.5 million units per1 ha, drill SKS-10.In addition to the plant growth regulators of the new generation of Radhostim, Regoplant, Stimpo, Deimos, Vimpel K and microfertilizers Quantum-grain, apply protectant Vitavaks 200 FF, herbicide Grodil Maxi and mineral fertilizer Nitroammophoska.Results and discussion. The best preparation for presowing treatment of seeds and dual-use on winter wheat varieties Rozkishna is Stimpo (increase of 0.29 t/ha or 5 %). When growing varieties Doskonala the best drugs for the treatment of seeds were Regoplant and Vimpel K (increase 0.22–0.23 t/ha or 4 %), and for dual-use Deimos and Vimpel K in combination with microfertilizers Quantum-grain (increase of 0.28 t/ha or 5 %).The best method of application of plant growth regulators and microfertilizers when growing seeds of spring barley varieties Wiklik is spraying the plants with tank mixtures of drugs Regoplant and Quantum-grain in the tillering stage and drugs Regoplant or Quantum-grain phase flag leaf (an increase of 0.23–0.31 in t/ha or 6–10 %), and varieties Parnas spraying plants, tank mixtures of drugs Radostim and Quantum-grain in the tillering stage and drugs Radostim or Quantum-grain phase flag leaf (increase to 0.22–0.28 t/ha or 6–8 %).Application of plant growth regulators and microfertilizer contributed to the obtaining of additional profit on winter wheat: a super-elite on 575–2450 uah/ha, elite 209–422 uah/ha, the first generation to 294–551 uah/ha, spring barley: super elite on 1610–3100 uah/ha, elite 522–1155 uah/ha, the first generation to 133–512 uah/ha. And also helped to get more number of seeds of the first generation of winter wheat in the range 586–873 t and spring barley 83–179 t.Conclusions: Annual application of modern plant growth regulators, microfertilizer and pesticides in the process of breeding new varieties, allows to increase the production of seeds in each stage of seed with improved high-yielding properties, which is an effective measure to accelerate their introduction into production. The effectiveness of the developed methods for increasing seed yield of winter wheat and barley depends on the drug and how it is used.

Background: Hypoxis hemerocallidea, arguably the most well-known medicinal species in South Africa, has been the subject of intensive harvesting from the wild leading to recent conservation concerns. The seeds of this species do not propagate easily and can lie dormant for up to twelve months.Materials and Methods: In the in vitro germination experiments water, acid and chemical pre-sowing treatments were performed to determine the germination response of this species in both light and dark conditions. In the ex vitro experiment, intact seeds were sown and left to germinate in a potting soil mix under greenhouse conditions.Results: Highest levels of germination (36.7-60.0% in the light and 36.7-46.7% in the dark) were achieved by treating mechanically scarified seeds with GA3 at various concentrations for 24 h. This was followed by scarified seeds soaked in water (26.7% in the light and 23.3% in the dark). Similar results (23.3 and 26.7%) were obtained in the 1% and 4% KNO3 treatments, respectively, under light conditions only. The fastest time to germinate was two days and was obtained in the 1200 ppm GA3 treatment in both light and dark conditions. Ex vitro germination of H. hemerocallidea seeds under greenhouse conditions was unsuccessful.Conclusion: H. hemerocallidea displays physical and non-deep physiological dormancy where pre-sowing treatments are required before the seeds will germinate.Keywords: medicinal plant; dormancy; GA3; pre-sowing

Conselho Nacional de Desenvolvimento Científico e Tecnológico Since in the 1994/1995 crop, occured an linear growth in area planted in system no tillage (NT), totaled in the 2010/11 crop 31.5 million hectares, accounting for 68% of the cultivated area. However, it is estimated that the loss of N applied in NT, can reach 78%. However, the application of N pre-sowing date has provided a result similar to traditionally applied. The experiment was conducted on the farm named of "Ilha de Cima" in Porto Firme, Minas Gerais, the forest region's, in a Red – Yellow Ultisol. Aimed to evaluate the efficiency of nitrogen fertilization with urea and granulated pearly in pre-sowing in the tillage system maize, with the desiccation of weeds. We evaluated the nitrogen fertilization (0, 40, 75, 110 and 150 kg ha-1) applied to the total area in the pre-seeding maize with the desiccation of weeds, time of nitrogen fertilizer in the pre-sowing in relation to desiccation (150 kg ha-1 N, 8 days before desiccation, even day, and 13 and 23 days after desiccation), the coverage nitrogen fertilization (0, 50, 100, 150 and 200 kg ha-1) in the V4 stage of development of the maize and yet forms of urea (pearly urea PETROBRAS - UPP, granulated urea PETROBRAS - UGT and granulated urea special - UGE). Thus the experiment consists of 28 treatments in an incomplete factorial, with the structure of a matrix Bacon, in a randomized block design with four replications. Weeds were collected in this area and they analyzed the contents of N and C. was planted maize bt (simple hybrid DKB 390 YG, early) with spacing of 0.9 m for a population of 50,000 plants per hactare. Were performed the quantification of the productivity, of the N absorbed by the shoot (Nab), of the recovery of N (RAN) and of the loss by volatilization of N. For productivity, we obtained a significant linear equation with a rate about 15 kg kg-1 N applied in coverage. There was also a linear response to the Nabs. And for the RAN was a decrease with increasing dose. In relation to the dose in pre-sowing there was a decline in productivity with increasing dose to the UPP, UGP and there was no significant difference to UGE. To the Nab and RAN there was no significant difference in UPP and UGP. However, for UGE an increase in the Nabs and RAN with increasing dose. How much the application time was difference significant only for productivity when used the UPP between 13 and 23 days after desiccation and to UGE between 8 days before with the other time. How much The N loss by volatilization was no significant difference for the different forms of urea. However in relation to the time we obtained the smallest loss when applied to 8 days before desiccation . Nitrogen fertilization in pre-sowing of corn in no-tillage system with the desiccation of weeds is effective. The UPP is more effective with the application before the desiccation of weeds, or in the maize planting. The UGP is most effective with the application in the weeds desiccation. Desde a safra brasileira de 1994/95 ocorreu crescimento linear da área manejada com o sistema plantio direto (SPD), totalizando na safra 2010/11 31,5 milhões de hectares, correspondendo a 68 % da área cultivada. No entanto, estima-se que a perda de N aplicado no SPD, pode atingir 78 %. Porém, a aplicação do N na pré-semeadura da cultura tem proporcionado resultado semelhante ao aplicado tradicionalmente. O experimento foi realizado na propriedade “Ilha de Cima”, no município de Porto Firme-MG, região da zona da mata, em um Argissolo Vermelho - Amarelo. Objetivou avaliar a eficiência da adubação nitrogenada com ureia perolada e granulada na pré- semeadura do milho em sistema plantio direto, com dessecação das plantas espontâneas. Avaliaram-se a adubação nitrogenada (0, 40, 75, 110 e 150 kg ha-1) aplicada em área total na pré-semeadura do milho com a dessecação das plantas espontâneas; a época da adubação nitrogenada na pré-semeadura em relação à dessecação (150 kg ha-1 de N aplicados 8 dias antes, na dessecação e 13 e 23 dias após dessecação); a adubação nitrogenada em cobertura (0, 50, 100, 150 e 200 kg ha-1) no estádio V4 de desenvolvimento vegetativo do milho e ainda formas de ureia (ureia perolada PETROBRAS – UPP, ureia granulada PETROBRAS – UGP e ureia granulada especial – UGE). Desta forma o experimento constitui de 28 tratamentos, em um fatorial incompleto, com a estrutura de uma matriz Baconiana, no delineamento em blocos ao acaso com quatro repetições. Foram coletadas plantas espontâneas presente na área e estas analisadas quanto ao teor de N e C. Foi plantado o milho bt (híbrido simples DKB 390 YG, precoce) com espaçamento de 0,9 m para população de 50.000 plantas por hectare. Foram realizadas a quantificação da produtividade, o N absorvido pela parte aérea (Nab), a recuperação de N (RAN) e a perda por volatilização de N. Para produtividade, obteve-se uma equação linear significativa com taxa cerca de 15 kg kg-1 de N aplicado em cobertura. Também houve reposta linear para o Nab. E para a RAN houve uma queda com aumento da dose aplicada. Em relação à dose em pré-semeadura houve uma queda da produtividade com o aumento da dose para UPP, UGP e não houve diferença significativa para UGE. Já para Nabs e o RAN não houve diferença significativa para UPP e UGP. No entanto para UGE houve um aumento do Nabs e RAN com aumento da dose. Quanto às épocas de aplicação houve diferença significativa apenas para produtividade quando utilizou-se a UPP entre 13 e 23 dias após a dessecação e para UGE entre 8 dias antes com as demais épocas. Quanto a perda de N por volatilização não houve diferença significativa para as diferentes formas da ureia. No entanto em relação à época obteve-se a menor perda quando aplicou-se 8 dias antes a dessecação. A adubação nitrogenada na pré-semeadura do milho em sistema de plantio direto com a dessecação das plantas espontâneas é eficaz. A UPP é mais eficaz com aplicação antes da dessecação das plantas espontâneas, ou na semeadura do milho. A UGP é mais eficaz com a aplicação na dessecação das plantas espontâneas.