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Search Results: 1 - 10 of 83673 matches for " Alessandro Guerra da Silva "
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AVALIA O DOS ESTáGIOS FENOLóGICOS DE CULTIVARES DE SORGO FORRAGEIRO EM DIFERENTES éPOCAS DE SEMEADURA EVALUATION OF PHENOLOGICAL STAGES OF FORAGE SORGHUM CULTIVARS IN DIFFERENT SOWING TIMES
Alessandro Guerra da Silva,Valterley Soares Rocha
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v36i2.2147
Abstract: A fim de obter informa es sobre o comportamento do sorgo forrageiro em diferentes épocas de semeadura, efetuou-se um grupo de ensaios no campo experimental do Departamento de Fitotecnia da Universidade Federal de Vi osa, durante o ano agrícola 1999/2000. Oito ensaios foram conduzidos, sendo iniciados na primeira quinzena do mês de outubro de 1999 até maio de 2000. O delineamento experimental utilizado, em cada ensaio, foi o de blocos casualizados com quatro repeti es. As cultivares de sorgo usadas foram: AG 2002, BR 501, BR 506, BR 601, BR 602 e BR 700 (forrageiros), AG 2005E e Massa 03 (duplo propósito) e AG 2501C e BRS 800 (corte e pastejo). Os estágios fenológicos (diferencia o floral, florescimento e matura o) de cada cultivar foram avaliados em cada época de semeadura. Os resultados obtidos permitiram concluir que as cultivares AG 2002, BR 501, BR 601, BR 602 e BR 700 apresentaram sensibilidade ao fotoperíodo, enquanto AG 2005E, AG 2501C, BR 506, BRS 800 e Massa 03 foram insensíveis. O decréscimo da temperatura ocasionou o atraso do desenvolvimento fenológico de todos os cultivares e a eleva o antecipou o ciclo das cultivares. PALAVRAS-CHAVE: Sorghum bicolor; fotoperíodo; cultivar; forragem; temperatura. To obtain information about the behavior of forage sorghum in different sowing times, a group of trials was set up in the experimental field of the Department of Plant Science, Universidade Federal de Vi osa, Minas Gerais State, Brazil during the 1999/2000 growing season. Eight experiments were used, starting in the first fortnight of October 1999 through May 2000. Each experiment was arranged in randomized blocks with four replications. The sorghum cultivars used were: AG 2002, BR 501, BR 506, BR 601, BR 602 and BR 700 (forage), AG 2005E and Massa 03 (dual purpose) and AG 2501C and BR 800 (cutting and grazing). The phenological stages (floral differentiation, flowering and maturation) for each cultivar were evaluated for each sowing time. It was concluded that the cultivars AG 2002, BR 501, BR 601, BR 602, and BR 700 were sensitive to photoperiod, while AG 2005E, AG 2501C, BR 506, BRS 800, and Massa 03 were insensitive. The temperature decrease caused a delay in the phenological development for all cultivars, while the increaseadvanced the cycle. KEY-WORDS: Sorghum bicolor; photoperiod; cultivar; forage; temperature.
Physiological Quality of Pigeonpea Seed after Application of Desiccant Herbicides  [PDF]
Raniele Tadeu Guimar?es, Itamar Rosa Teixeira, André José Campos, Gisele Carneiro da Silva, Ivano Alessandro Devilla, Alessandro Guerra da Silva, Paulo César Timossi
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.66089
Abstract: The pre-harvest application of herbicides may impair seed quality. This way, this paper was conducted to evaluate the effects of the application of desiccant herbicides on the physiological quality of pigeonpea seeds. Six batches of seeds from plants desiccated with glyphosate were evaluated at doses: 1.125 (B1), 1.5 (B2) and 1.875 L·ha-1 (B3); and Gramocil (20% Paraquat + 10% Diurom) at doses: 1.5 (B4) and 2 L·ha-1 (B5), and a control which received no application (B6). Seed viability was assessed through the germination standard test, and vigor through the first germination count, accelerated aging, electrical conductivity, seedling length, seedling dry matter and biomass density tests. The experimental design was the completely randomized, with four replications. Data were submitted to variance analysis, and when significant effects were observed, the Scott- Knott test was carried out at 5% probability using the SISVAR 5.1 software. The results showed that: a) the application of 1.875 L·ha-1 of glyphosate was harmful to pigeonpea seed viability and vigor, evaluated through the accelerated aging test; b) applications of glyphosate in a 1.875 L·ha-1 dose and Gramocil in 2 L·ha-1 resulted in low vigor according to the electrical conductivity test of seeds; and c) the seed vigor measured by the first count, seedling length, seedling dry matter and biomass density test was not influenced by the type of desiccant applied.
EFFECT OF SILICON FERTILIZER ON FORAGE GRASSES AND SOIL CHEMICAL CHARACTERISTICS EFEITO DA ADUBA O SILICATADA SOBRE GRAMíNEAS FORRAGEIRAS E CARACTERíSTICAS QUíMICAS DO SOLO
Pedro Henrique Kornd?rfer,Gisele Carneiro da Silva,Itamar Rosa Teixeira,Alessandro Guerra da Silva
Pesquisa Agropecuária Tropical , 2010, DOI: 10.5216/pat.v40i2.3922
Abstract: This research assessed the effect of calcium silicate application to soil surface on dry matter production and Si concentration on grass shoots, as well as chemical characteristics of a soil under degraded forage grass pasture. The experiment was carried out in a greenhouse, using a completely randomized design, in a 5x2 factorial arrangement, with four replicates. Treatments consisted of five calcium silicate doses (0 kg ha-1; 500 kg ha-1; 1,000 kg ha-1; 1,500 kg ha-1; and 2,000 kg ha-1) and two forage grasses (Brachiaria brizantha cv. Marandu and Panicum maximum cv. Momba a). Shoot cuttings were performed at 45 and 95 days after sowing. Shoot dry mass accumulation and absorbed Si foliar concentrations were quantified, besides soil pH, Ca, P, Al, and V values, after grass harvesting. Calcium silicate application induced higher absorption of Si in Marandu, as well as in Momba a. Marandu cultivar dry mass accumulation did not differ from Momba a. Calcium silicate application increased pH and soil base saturation decreased the aluminum level. KEY-WORDS: Brachiaria brizantha; Panicum maximum; silicon; acidity correction. Este trabalho avaliou o efeito da aplica o superficial de doses de silicato de cálcio sobre a produ o de matéria seca e as concentra es de Si na parte aérea, assim como os atributos químicos do solo em pastagem degradada de gramíneas forrageiras, cultivadas em casa-de-vegeta o. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 5x2, com quatro repeti es. Os tratamentos foram compostos por cinco doses de silicato de cálcio (0 kg ha-1, 500 kg ha-1, 1.000 kg ha-1, 1.500 kg ha-1 e 2.000 kg ha-1) e duas gramíneas forrageiras (Brachiaria brizantha cv. Marandu e Panicum maximum cv. Momba a). Foram realizados dois cortes, aos 45 e 95 dias após a semeadura, sendo quantificada a produ o de massa seca da parte aérea e as concentra es foliares de Si absorvido pelas plantas, além dos valores de pH, Ca, P, Al e V no solo, após a colheita das gramíneas. A aplica o de silicato de cálcio resultou em maior absor o de silício, tanto na cv. Marandu como na cv. Momba a. A produ o de massa seca da cv. Marandu n o diferiu da cv. Momba a. O silicato de cálcio aumentou o pH e a satura o por bases do solo e reduziu o teor de alumínio.
EVALUATION OF GRAIN SORGHUM CULTIVARS FOR DOUBLE CROPPING IN THE SOUTHWEST OF GOIáS STATE, BRAZIL AVALIA O DE CULTIVARES DE SORGO GRANíFERO NA SAFRINHA NO SUDOESTE DO ESTADO DE GOIáS
Alessandro Guerra da Silva,Alexandre Stremel Barros,Luis Henrique Silva Carregal Pereira da Silva,Eduardo Bezerra de Mor?es
Pesquisa Agropecuária Tropical , 2009, DOI: 10.5216/pat.v39i2.3320
Abstract: Sorghum is a crop of great importance for double cropping, in the Brazilian Central-West region. Within this region, in the Southwestern Goiás State, a research was conducted to select sorghum (Sorghum bicolor (L.) Moench) cultivars, in the municipalities of Montividiu, Rio Verde, and Santa Helena de Goiás. A randomized blocks design, with four replications, was used. The grain sorghum cultivars tested were: BR 304, 741, 822, Catuy, and the experimental hybrid V 00069. The cultivars were sown on March 5, 2005. The evaluated characteristics were: yield, weight of thousand grains, plant height, and flowering and maturation dates. The results showed the interaction genotype x environment for all evaluated characteristics. The region of Montividiu presented better potential for sorghum grain production. Early flowering and harvest allowed higher grain yields. KEY-WORDS: Sorghum bicolor; grain yield; interaction genotype x environment. O sorgo é uma cultura de grande importancia nos cultivos de safrinha na regi o Centro-Oeste. Com o objetivo de selecionar cultivares de melhor desempenho agron mico, para a safrinha na regi o sudoeste de Goiás, foram instalados ensaios nos municípios de Montividiu, Rio Verde e Santa Helena de Goiás. Foi empregado o delineamento experimental de blocos casualizados, com quatro repeti es, utilizando-se as cultivares de sorgo BR 304, Catuy, 741, 822 e o híbrido experimental V 00069. A semeadura foi realizada no dia 05 de mar o de 2005. As características avaliadas foram: rendimento de gr os e peso de mil gr os, altura de plantas e datas de florescimento e maturidade fisiológica. Foi constatada a presen a da intera o genótipo x ambiente, em todas as características avaliadas. O município de Montividiu apresentou maior potencial para o cultivo de sorgo. A maior precocidade para flora o e colheita possibil
Nutritional Characteristics of Brachiaria brizantha Cultivars Subjected to Different Intensities Cutting  [PDF]
Kátia Aparecida de Pinho Costa, Eduardo da Costa Severiano, Gustavo André Simon, Patrícia Soares Epifanio, Alessandro Guerra da Silva, Raoni Ribeiro Guedes Fonseca Costa, Charles Barbosa Santos, Carlos Ribeiro Rodrigues
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.513210
Abstract:

This study evaluated the nutritional characteristics of Brachiaria brizantha cultivars subjected to three cutting intensities in the course of one year. The experiment was conducted at the University of Rio Verde. The experiment was performed as a randomized 3 × 3 factorial in complete block design with three replications and repeated measures in the time. Three Brachiaria brizantha cultivars (Marandu palisadegrass, Xaraes palisadegrass, and Piata palisadegrass), were tested at three cutting intensities (10, 20, and 30 cm sward height). The evaluations were conducted on the same plots throughout one year and during all four seasons (autumn, winter, spring, and summer). The results showed that the Piata palisadegrass had the best chemical composition compared to the Marandu palisadegrass and Xaraes palisadegrass. The management of Brachiaria brizantha cultivars at the lowest residual height (10 cm) affected the nutritional value of these feed grasses. Seasonality also influenced the nutritional value of these forages.

Consórcio sorgo-soja. V. Comportamento de híbridos de sorgo e cultivares de soja consorciados na entrelinha no rendimento de forragem
Rezende, Pedro Milanez de;Silva, Alessandro Guerra da;Corte, Edivandro;Botrel, élberis Pereira;
Ciência Rural , 2001, DOI: 10.1590/S0103-84782001000300001
Abstract: with the purpose of evaluating the behavior of sorghum and soybean cultivars in intercropping for forage production and sorghum in monoculture, a trial was conducted in the agricultural year of 1996/1997 at the department of agriculture of the universidade federal de lavras- mg, on a distrophic red dusky latosol. the experimental design was that of randomized blocks in a 4 x 4 + 4 factorial scheme, with three replications, being made up of four hybrids of forage sorghum (ag-2002, ag-2006, br-601 and cmsxs-756), four soybean cultivars (cac-1, doko rc, ufv-16 and ufv-17) and four additional treatment corresponding to the respective monoculture of sorghum. in the intercropping, a single cutting chose to the soil surface at r5 stage was performed (beginning of the set of the soybean crop seeds), in the sorghum monoculture the cut was done, with grains in mealy stage. the results obtained made it evident that the combination of the cultivar ufv-16 with the hybrids ag-2002 and ag-2006 were the ones which provided the greatest green mass, dry matter and total crude protein yields. both in the consortium and monoculture, the hybrid ag-2002 was that which stood out the most for dry matter and green mass production. in general, the consortium system provided, in relation to monocultivation, the highest green mass,dry matter and total crude protein yields.
Efeito de doses e da época de aplica??o de nitrogênio nos caracteres agron?micos da cultura do milho sob plantio direto
Gomes, Renata Ferreira;Silva, Alessandro Guerra da;Assis, Renato Lara de;Pires, Fábio Ribeiro;
Revista Brasileira de Ciência do Solo , 2007, DOI: 10.1590/S0100-06832007000500010
Abstract: maize is an important crop for grain production in the center-west region of brazil. an experiment was installed in rio verde (go) in the 2002/03 growing season to evaluate the effect of doses and timing of nitrogen application on the agronomic traits of no-tillage maize. the experiment was evaluated as a 6 x 4 + 1 factorial in a randomized complete block design with 4 repetitions. the factors consisted of six nitrogen applications (before sowing; at sowing; top dressed 30 days after sowing; at sowing and top dressed 30 days after sowing; at sowing and top dressed 30 and 45 days after sowing; pre-sowing and at sowing and top dressed 30 days after sowing) and four nitrogen levels (25, 50, 100 and 150 kg ha-1), plus one control treatment without nitrogen application. the corn hybrid p30k75 and urea fertilizer were used. the dose of 150 kg ha-1 led to the highest grain yield, nitrogen leaf concentration, grain weight per ear and plant height. the nitrogen leaf concentration was higher for applications in top dressing, at sowing and top dressed 30 days after sowing and at sowing and after top dressed 30 and 45 days after sowing. the nitrogen applications as top dressing (30 days) and split application (pre-sowing plus at sowing and top dressed 30 days after sowing ) led to the highest kernel weight per ear and per 1.000 grains. the effect of dose or date of nitrogen application on protein yield and disease severity was not significant. the highest net profit was obtained with the application of 25 kg ha-1 nitrogen at sowing.
Tratamento de sementes de sorgo com inseticidas
Vanin, Alisson;Silva, Alessandro Guerra da;Fernandes, Camila Pereira Caixeta;Ferreira, Wenderson Sousa;Rattes, Jurema Fonseca;
Revista Brasileira de Sementes , 2011, DOI: 10.1590/S0101-31222011000200012
Abstract: seed treatment with insecticides is an effective tool in integrated pest management, but information on selective products to treat sorghum seeds is limited. the objective of this study was to evaluate the effects of treating sorghum seeds with insecticides containing one or two active ingredients, with and without storage for 30 days, on the early plant development. the experiment was conducted at fesurv-universidade de rio verde, in rio verde-go, using ten insecticides (thiodicarb, fipronil, acephate, thiamethoxam, imidacloprid, [imidacloprid+thiodicarb], imidacloprid+thiodicarb, imidacloprid+fipronil, thiamethoxam+thiodicarb, thiamethoxam+fipronil, plus a non-insecticide control, with and without 30 day seed storage. the results showed that storage of sorghum seeds treated with insecticides for 30 days reduced the germination percentage. the imidacloprid+thiodicarb mixture has more potential for treating sorghum seeds. the insecticide acephate causes more phytotoxicity to the sorghum seedlings compared to fipronil, thiamethoxam and the thiamethoxam+thiodicarb mixture. the insecticides did not adversely affect sorghum seed vigor.
POPULATION DYNAMICS OF Spodoptera frugiperda (J. E. SMITH), Diatraea saccharalis (FABRICIUS) AND Doru luteipes (SCUDDER) IN CONVENTIONAL AND Bt TRANSGENIC MAIZE
LAíS FERNANDA DE ARAúJO,ALESSANDRO GUERRA DA SILVA,IVAN CRUZ,EDUARDO LIMA DO CARMO
Revista Brasileira de Milho e Sorgo , 2011,
Abstract: New technologies to pests control in maize should be periodically reviewed for adoption in the cerealproducing regions. This study aimed to evaluate the population dynamics of Spodoptera frugiperda (J. E. Smith)(Lepidoptera: Noctuidae), Diatraea saccharalis (Fabricius) (Lepidoptera: Pyralidae) and the predator Doru luteipes(Scudder) (Dermaptera: Forficulidae) in the development of conventional and Bt transgenic maize. The trial was setup in the off-season cultivation in Rio Verde, GO, Brazil. The experimental design was the randomized blocks with 24repetitions. The hybrids P 3041 and P 3041YG were used, with a population of 50,000 plants.ha-1. It were evaluatedthe number of insects and the damages caused by the caterpillars on the leaves, stems and tassel, quantification andpresence of internodes with galleries, plant height and insertion of ear, grain mass per ear and grain yield. The resultsallowed concluding that the hybrid P 3041YG showed lower damage of S. frugiperda and presented higher grain massof ear and grain yield compared to the P 3041conventional hybrid.
Fontes e doses de zinco no feijoeiro cultivado em diferentes épocas de semeadura = Sources and doses of zinc in common bean cultivated in different sowing seasons
Itamar Rosa Teixeira,Aluízio Borém,Alessandro Guerra da Silva,Hamilton Kikuti
Acta Scientiarum : Agronomy , 2008,
Abstract: Este trabalho teve por objetivo avaliar, em diferentes épocas de cultivo a produ o do feijoeiro, submetido à aplica o foliar de fontes e doses de zinco. Foi utilizado o delineamento de blocos casualizados, em esquema fatorial 3 x 2 x 5, com quatro repeti es. Os tratamentos envolveram a combina o de três safras de cultivo (inverno, águas e seca), duas fontes de zinco (sulfato e cloreto de zinco) e cinco doses de zinco (0, 100, 200, 400 e 800 g ha-1), aplicadas via foliar, aos 25 e 35 dias após emergência da cultura.Na safra de inverno, foram obtidos os maiores rendimentos de gr os e de seus componentes (número de vagens por planta e número de gr os por vagem) e teor foliar de zinco, comparativamente, às safras das águas e seca. N o houve efeito da intera o entre épocas desemeadura, doses e fontes de zinco. Em solos com teor de Zn próximo de 2,1 mg dm-3, n o houve aumento de produtividade para o feijoeiro com a utiliza o de cloreto ou sulfato de zinco, aplicados via foliar. This work was carried out with the objective of evaluating dry bean yield in different seasons, submitted to foliar application of different sources and doses of zinc. A randomized block design with four replications was used in a 3 x 2 x 5 factorial arrangement. The treatments were formed by the combination of three growing seasons(“fall/winter”, “spring/summer” and “fall/summer” seasons), two zinc sources (zinc sulfate and zinc chloride) and five zinc doses (0, 100, 200, 400 and 800 g ha-1), divided into leaf sprayings at 25 and 35 days after emergence (DAE). For the winter crop, a greater increasewas observed in grain yield, its main components (number of pods per plant and number of grains per plant) and leaf-zinc content, as compared to the other two seasons. There was no interaction between growing seasons, doses and sources of zinc. In soils with zinc contentof 2.1 mg dm-3, the addition of this nutrient by foliar application did not result in increase of bean yield.
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