Períodos de interferência de plantas daninhas na cultura do girassol

The interference of weeds in sunflower cultivation can significantly reduce the productivity of achenes. The objective of this study was to determine the period before interference and total period of interference of the weed community on productivity and achene oil of sunflower cultivation. The experiment was conducted under field conditions in the fieldin Botucatu (SP) in the 2007/2008 agricultural year. The experimental design was a randomized complete block with four replications. The treatments were composed of portions represent periods of control and presence of weeds. For control periods, the culture was kept free of weeds by increasing periods of 7, 14, 21, 28, 35, 42, 49 and 110 days after the emergence (DAE) of sunflower. For periods of coexistence, the culture was maintained in the presence of the weed community for the same periods. We assessed the following variables: diameter of chapters, achene yield, oil yield of sunflower, density and dry matter of weeds and phytosociological indices. The period before the interference was 35 DAE culture to the productivity of achenes, and the total period of interference lasted until 24 DAE. For oil yield, the period before the interference was 25 DAE, whereas the total period of interference lasted for 14 DAE.

Eficiência de escórias de siderurgia na cultura do feijoeiro em sistema de semeadura direta

In the no till system, soil acidity correction practice is restricted to limestone use and there is little information regarding slag. The study aimed to evaluate the amendments in soil chemical properties, yield and bean nutrient uptake according to the application forms of slags, compared to limestone, in the implantation of no till system. The experiment was conducted in the field at College of Agricultural Sciences, Botucatu (SP) from December 2010 to May2011. The treatments consisted of two application ways of seven soil acidity correctives: steel slag, blast furnace slag, ladle furnace slag, stainless steel slag (agrosilício), wollastonite, lime and calcined dolomite lime, plus one control without corrective application. Each material dose was calculated to raise the base saturation to 70%. Soil acidity was neutralized down to 20cm with limestones, whereas for wollastonite and ladle furnace slag those effects occurred down to 10cm, for steel slag, blast furnace slag and agrosilício the corrective effect was restricted to the first 5cm. The bean yield increased by application of correctives in soil acidity, without differences between the application ways.

Estimativas da radiação global incidente em superfícies inclinadas com base na razáo de insolação

Estimating equations of global radiation based on the sunshine duration were proposed for horizontal surface and with inclination of 12.85, 22.85 and 32.85° facing the North in Botucatu, SP, Brazil, in monthly, seasonal and annual groupings of data. Simple linear correlations were applied (for definition of the linear and angular coefficients of Angstrom-Prescott model), in a database measured in all three inclinations in different periods (22.85°: 04/1998 to 07/2001; 12.85°: 08/2011 to 02/2003; and 32.85°: 03/2003 to 12/2007) concomitant with horizontal measures and sunshine duration. The statistical performance of the model was analysed by the means absolute error (MBE), the square root of the mean square error (RMSE) and the index adjustment (d). The minimum global radiation transmissivity varied from 14.35% in August (12.85°) to 27.86% in December (32.85°) and the maximum transmissivity ranged between 62.10% and 78.90%, for June (32.85°) and December (12.85°). Increasing the angle of inclination surface increased the scattering and decreased the index of adjustment and performance. The worst results were found for application of the seasonal and annual models in the months of autumn and winter for 32.85° (RMSE below 42.93% and adjustment superior to 0.4693).

Estimativas das radiações direta e difusa em superfícies inclinadas com base na razáo de insolação

Statistical equations were obtained and evaluated with annual, seasonal and monthly data groupings for estimates of direct and diffuse components of solar radiation based on the sunshine duration (ratio of sunshine and photoperiod) incident on horizontal and inclined surfaces to 12.85, 22.85 and 32.85° with facing to North, in Botucatu, SP. The ratios between the two components and radiation at the top of the atmosphere were used, in a database whose inclinations were measured in three different periods (22.85°: 04/1998 to 07/2001; 12.85°: 08/2011 to 02/2003; and 32.85°: 03/2003 to 12/2007) and concomitant with horizontal measures and sunshine duration. The correlations showed a linear and second degree polynomial behavior for the direct and diffuse radiation, with higher coefficients of determination in periods of low variation in the coverage of the sky (cloudiness). The highest values of the direct and diffuse radiation were found in winter and summer, respectively for all surfaces evaluated. The increase in the inclination angle decreased the performance of equations in all groups of data with increase in scattering and decrease in index of the adjustment, however, the monthly equations allowed better performance for the two components.

Análise funcional da musculatura do assoalho pélvico pós-parto em mulheres primigestas

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

Lodos de esgoto, escória de aciaria e lama cal na cultura da soja sob sistema plantio direto em latossolo vermelho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Doses e modos de aplicação de fósforo na nutrição e produção do feijoeiro cultivar Pérola

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Densidades e arranjos populacionais de milho e componentes agronômicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seletividade de herbicidas à cultura da mandioca

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Propriedades físicas de um latossolo vermelho manejado com material orgânico e submetido à compactação

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Assistência de ar e aplicação em volume baixo no controle da ferrugem asiática da soja (Phakopsora pachyrhizi Sydon & Sydon

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seletividade do herbicida saflufenacil aplicado em pós-emergência em dez variedades de cana-de-açúcar na condição de soca

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Adubação nitrogenada e inoculação com rizóbio no feijoeiro em sucessão ao milho consorciado com braquiárias no sistema plantio direto

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Métodos não convencionais para avaliação da porosidade e da densidade do solo de um latossolo vermelho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desempenho de cultivares transgênicas de soja em sucessão a culturas de inverno em semeadura direta

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)