Sistemas de cultivo para o milho de primeira safra e doses de nitrogênio em feijoeiro e trigo em sucessão

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Qualidade da Água Residuária para Irrigação do Trigo

O tratamento de esgotos sanitários e o seu posterior reúso, tornou-se uma alternativa viável para a irrigação, atividade que utiliza em torno de 70 % de toda a água consumida no planeta. Nesse sentido, o objetivo deste estudo foi monitorar durante todo o ciclo do trigo, os teores de Ferro e Manganês, bem como valores de pH e condutividade elétrica da água residuária utilizada para irrigação da cultura por gotejamento. A água residuária utilizada no estudo foi proveniente da Estação de Tratamento de Esgotos (ETE) da cidade de Botucatu-SP. No período de maio a outubro de 2011 a amostragem da água residuária foi realizada semanalmente, na saída da ETE. Foram determinados os seguintes parâmetros: Boro (B), Cobre (Cu), Ferro (Fe), Manganês (Mn) e Zinco (Zn), segundo metodologia adaptada de Malavolta et al. (1997). O pH e a condutividade elétrica (CE) foram determinados com auxilio de um pHmetro e condutivímetro, respectivamente. Não foi observado teores de Fe e Mn e valores de pH que comprometessem o sistema de irrigação, ou seja, que apresentasse alto potencial de risco de obstrução de tubulações e emissores (gotejamento). Os valores de CE indicam que a água residuária pode ser usada no solo, sempre que houver grau elevado de lixiviação, sem maior comprometimento das culturas.

Características agronômicas do trigo em função de Azospirillum brasilense, ácidos húmicos e nitrogênio em casa de vegetação

The objective of this study was to investigate the effect of the combined use of Azospirillum brasilense, humic acid and different levels of nitrogen on agronomic characteristics of wheat under greenhouse conditions. The experiments were installed on May 21, 2011 and proceeded to harvest on September 13, 2011. The experimental design was a randomized complete block in a 4 x 4 factorial design with four replications. The first factor relates to the combination of strain Ab-V5 of A. brasilense with humic acids, with the following treatments: control, Ab-V5, humic acid and Ab-V5 + humic acid and the second factor refers to nitrogen levels (0, 30, 60 and 90 kg ha-1 N). Most variables in the analysis had a positive linear effect of treatments depending on nitrogen fertilization, and only for variable weight of hundred grains, the negative effect was linear. There were no significant differences between the variances in grain production. It was concluded that the combined use of Ab-V5 + humic acid promotes the production mainly of dry leaves and are not responsive to nitrogen fertilizer for other productive components under study, as well as grain yield.

Coberturas vegetais e doses de nitrogênio em trigo sob sistema plantio direto

The application of conservation practices in production systems is essential to the sustainability of the agricultural production capacity. The use of different cover crops can reduce the need of topdressing nitrogen fertilizers in wheat crops. This study aimed at evaluating the influence of cover crops residues (millet, sunn hemp, pigeon pea, millet + sunn hemp, millet + pigeon pea and fallow ground), grown previously to the summer crop (rice), and topdressing nitrogen doses (0 kg ha-1, 25 kg ha-1, 50 kg ha-1, 75 kg ha-1, 100 kg ha-1 and 125 kg ha-1), in the development and yield of wheat under no-tillage system. The experiment was carried out in Selvíria, Mato Grosso do Sul State, Brazil, in a Red Oxisol, in 2009/2010 and 2010/2011. The experimental design was randomized blocks, in a 6x6 factorial scheme. The cover crops developed during August/October (2009/2010) and September/November (2010/2011), previously to the summer crop, with the chemical desiccation performed respectively at 73 and 55 days after sowing. The wheat (winter) was sown in May, in both periods, and harvested at 113 (2009/2010) and 106 (2010/2011) days after emergence. The cover crops residues of pigeon pea, sunn hemp and millet + sunn hemp, preceding wheat, provided higher wheat yields, relatively to the fallow ground. The wheat yield showed a quadratic response to the increase in the nitrogen availability, reaching higher yields with the nitrogen doses estimated in 113 kg ha-1 (2010) and 98 kg ha-1 (2011).

Efeito da cobertura do solo com palhiço de cana-de-açúcar na emergência de monocotiledôneas infestantes em campo

Pós-graduação em Agronomia (Agricultura) - FCA

Estimativa da produtividade de trigo em função da adubação nitrogenada utilizando modelagem neuro fuzzy

Currently new techniques for data processing, such as neural networks, fuzzy logic and hybrid systems are used to develop predictive models of complex systems and to estimate the desired parameters. In this article the use of an adaptive neuro fuzzy inference system was investigated to estimate the productivity of wheat, using a database of combination of the following treatments: five N doses (0, 50, 100, 150 and 200 kg ha(-1)), three sources (Entec, ammonium sulfate and urea), two application times of N (at sowing or at side-dressing) and two wheat cultivars (IAC 370 and E21), that were evaluated during two years in Selviria, Mato Grosso do Sul, Brazil. Through the input and output data, the system of adaptive neuro fuzzy inference learns, and then can estimate a new value of wheat yield with different N doses. The productivity prediciton error of wheat in function of five N doses, using a neuro fuzzy system, was smaller than that one obtained with a quadratic approximation. The results show that the neuro fuzzy system is a viable prediction model for estimating the wheat yield in function of N doses.

Aplicações sucessivas de lodo de esgoto no girassol e efeito residual no trigo e triticale

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Adjuvantes em pulverizações de fungicidas na cultura do trigo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desoxinivalenol em farinha de trigo: otimização de método analítico, validação e ocorrência

Pós-graduação em Alimentos e Nutrição - FCFAR

Componentes produtivos do trigo afetados pela densidade de semeadura e aplicação de regulador vegetal

Improvement on yield potential of plants by crop management is the main research challenge due to the growing of food demand worldwide. The objective of this work was to study physiological and morphological traits and its relationship with yield components and yield of wheat as affected by sowing densities and plant growth regulators. The experimental design was a split-plot design with four replications. The plots were consisted by four sowing densities ( 30, 50 70 and 90 plants m(-1)) and the subplots were consisted by plant growth regulators [control, (IBA+GA+KT), Trinexapac-Ethyl e (IBA+GA+KT) + Trinexapac-Ethyl]. Dry matter accumulation, plant height, source-sink distance, gas exchange and yield were determined. Trinexapac-Ethyl application resulted in decreasing of plant height, source-sink distance and flag leaf length; however, the grain yield was not affected. The number of plants per unit area affected dry matter accumulation. Higher dry matter accumulation showed direct relationship with yield and yield components in lower plant densities.

Manejo da adubação com sulfato de amônio no desempenho produtivo do milho cultivado após aveia e trigo

The time, dose and applied nutrients in corn have a direct effect on its productivity. Therefore, the objective was to study the application of N and S in corn as ammonium sulfate, in succession to wheat and oats and evaluate different forms of fertilizer management. The experiment was conducted in a randomized block design in Oxisol (Hapludox). The five treatments with N, at a dose of 120 kg ha(-1) were applied in 20 plots (5x4), according to the management of fertilizer: T1-N (120 kg ha(-1)) full at sowing, T2-N (120 kg ha(-1)) total coverage; T3-N (40 kg ha(-1)) at sowing and N (80 kg ha(-1)) in coverage; T4-N advance in wheat sowing and sowing oats (120 kg ha(-1)), T5-(control). The S doses were corresponding to their concentrations in the fertilizer. Only wheat received a dose of 24 kg N ha(-1) at sowing all plots and oats received 24 kg N ha(-1) at sowing only the portions related to treatment with anticipation of corn N (T4). We evaluated the biomass production of winter crops (oats and wheat), according to the fertilization at sowing, and also the influence of winter crops and management of ammonium sulfate, the corn yield. The oats produced more dry matter in relation to wheat, positively influencing the corn yield, regardless of fertilizer management. The anticipation of ammonium sulfate, the sowing of oats, was favorable to corn yield, equating to other forms of management of fertilizer. Rotation corn and oats, forms management, ammonium sulphate, at seeding, topdressing or applied in split were equally efficient in corn yields.

Perfilhamento do trigo afetado pela densidade de semeadura e aplicação de reguladores vegetais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Resistência a fungicidas estrobilurinas em populações de Pyricularia oryzae de áreas de trigo no Brasil

Pós-graduação em Agronomia - FEIS

Doses, fontes e épocas de aplicação de nitrogênio influenciando teores de clorofila e produtividade do trigo

To achieve high wheat yield, correct management of N fertilization and the use of high yield potential cultivars are necessary. The aim of this study was to evaluate the effects of different application rates and sources of N, applied totally at sowing or in topdressing, on grain yield and yield components of two irrigated wheat cultivars under a no-till system, grown in a Cerrado (Brazilian tropical savanna) region of low altitude. A randomized block design was used in a 5 x 3 x 2 x 2 factorial arrangement with three replications, combining five levels of N (0, 50, 100, 150, and 200 kg ha(-1)), three sources of N (Entec (R), ammonium sulfate, and urea), and two application times (at sowing, near the rows, or in topdressing) in two wheat cultivars (IAC 370 and Embrapa 21). The wheat cultivars had similar grain yields. There was no difference among the sources of N for grain yield and yield components. The N applied totally at sowing did not differ from the traditional application at sowing and in topdressing for production of irrigated wheat in no-tillage. The increase in application rates of N increased the leaf N contents and chlorophyll, plant height, and the number of ears per m(2). Grain yield of the wheat cultivars IAC 370 and Embrapa 21 increased up to the application rates of 134 and 128 kg ha(-1) of N, respectively, regardless of application time and source of N. The positive correlation between chlorophyll leaf content and grain yield in accordance with N fertilization levels indicates that N fertilization in topdressing can be recommended based on SPAD readings of leaf chlorophyll performed at 38 days after wheat plant emergence.

Desempenho agronômico do milho e do trigo em função da inoculação com azospirillum brasilense e doses e fontes de nitrogênio

Pós-graduação em Agronomia - FEIS