Perfilhamento do trigo em função da aplicação de regulador vegetal

Tillers survival and yield potential are genetically determined and strongly influenced by environmental conditions during the emission and establishment stage. This experiment was carried in order to study effects of application of growth regulator (Ax+GA+CK) on tiller survival and yield potential of wheat. The experiment was carried out from March to July 2010. A 2 × 2 factorial randomized block design with five replications was used. Two wheat cultivars (IAC 370 and IAC 375) and application or not of Ax+GA+CK at the beginning of tillering stage were evaluated. Tiller emission were evaluated at five ages (19, 26, 33, 40 e 47 days after emergence) and yield components were determined by each individual structure evaluation, comparing to the main stem. Growth regulator application improved the tiller survival when emitted in the first week after application. Tiller yield potential decreased in late emission periods of tillers in both cultivars tested, influenced by different traits of each cultivar. IAC 370 showed higher tiller emission, however, the number of viable tillers were higher for the IAC 375.

The no-tillage system and cover crops-Alternatives to increase upland rice yields

Upland rice (Oryza sativa L.) cultivation has been increasing in importance in Asia while water availability for irrigation has been decreasing because of rapid growth in industry and urban centers. Therefore, the development of technologies that increase upland rice yields under aerobic conditions, thereby saving water, would be an effective strategy to avoid a decrease in global rice grain production. The use of the no-tillage system (NTS) and cover crops that maintain soil moisture would prove advantageous in the move toward sustainable agriculture. However, upland rice develops better in plowed soil, and it has been reported that this crop does not perform well under the NTS. Therefore, the aim of this study was to investigate the effect of cover crops on upland rice grain yield and yield components sowed in a NTS. A field experiment was conducted during two growing seasons (2008-2009 and 2009-2010), and treatments consisted of growing rice under five cover crops in a NTS and two control treatments under the conventional tillage system (plowing once and disking twice). Treatments were carried out in a randomized block design with three replications. Our findings are as follows: On average, Brachiaria brizantha (12.32Mgha-1), Brachiaria ruziziensis (11.08Mgha-1) and Panicum maximum (11.62Mgha-1) had outstanding biomass production; however, these grasses provided the worst upland rice yields (2.30, 2.04, and 2.67Mgha-1, respectively) and are not recommended as cover crops before upland rice. Millet and fallow exhibited the fastest straw degradation (half-lives of 52 and 54 days, respectively), and millet exhibited the fastest nitrogen release (N half-life of 28 days). The use of a NTS was promising when millet was used as a cover crop; this allowed the highest upland rice yield (3.94Mgha-1) and did not statistically differ from plowed fallow (3.52Mgha-1). © 2012 Elsevier B.V.

Response of rice cultivars to nitrogen in upland conditions

Against the background of a growing world population, rice (Oryza sativa L.) consumption is expected to grow faster than its production. Therefore, an appropriate question would be: how to increase productivity in the shortterm? In this respect, it becomes important the implementation of modern agricultural production systems, such as upland rice with supplemental sprinkler irrigation. Additional information is needed to maximize the available resources, with special attention given to research on the use of nitrogen. This study aimed to evaluate the agronomic performance of commercial rice cultivars with different plant characteristics in upland conditions with supplemental sprinkler irrigation, when subjected to nitrogen in topdress application at the R1 stage (panicle differentiation). The experiment was arranged in a randomized block with split plot design, with 65 treatments, consisting of the combination of 13 cultivars in the plots, and five nitrogen levels in the subplots (0, 40, 80, 120 and 160 kg ha-1), with four replications. Genetic variability was detected among rice cultivars and the agronomic performance in response to the applied nitrogen. The topdressing application of nitrogen increases, in general, the production components and grain yield in rice. Cultivars BRS Primavera, Caiapó and IAC 202 stood out for grain yield, followed by Baldo, Carnaroli, BRS Curinga and IAC 500 with lower yields.

Nutrição e produtividade do crambe em razão da adubação de semeadura na safrinha

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Características agronômicas do feijão caupi inoculado em função de lâminas de irrigação e de níveis de nitrogênio

The aim of this study was to evaluate the effect of different irrigation depths and nitrogen levels on the agronomic characteristics of inoculated cowpea. The experiment was arranged in splitplots, with the levels of nitrogen in the plots and the depth of irrigation in the splitplots, in a randomized block design, with two repetitions. The irrigation depth corresponded to 578 mm (L1), 512 mm (L2), 429 mm (L3), 299 mm (L4) and 240 mm (L5), and the nitrogen levels of 0, 30, 60 and 90 kg ha-1 of N. The nitrogen levels showed significant effect on the yield components of cowpea. The irrigation depth showed significant effects on productivity of bean cowpea, with the depth of 426.21 mm estimated for obtaining the maximum productivity of 2820.03 kg ha-1.

Parâmetros genéticos entre caracteres quantitativos no girassol como critério de seleção para produtividade de aquênios

Two experiments were conducted in southern Brazil in no-tillage system, in order to estimate genetic parameters and the direct and indirect effects of components for achene yield as a selection criterion in sunflower. We analyzed eight sunflower hybrids at two locations, in a randomized complete block design with four replicates, determined through quantitative descriptors: insertion height of the head, and head stem diameter, weight of 1000 achenes, number of achenes per head, mass by achene head and yield achene. Estimates of genetic parameters were based on combined analysis, decomposing interactions in genetic and environmental components. Considering the coefficient of genetic variation, indirect effects of components and heritability, there are higher possibilities for responses to selection in sunflower achenes by descriptors mass and mass of achenes per head, with its indirect association interrelated pathways for the increase in the achenes of yield.

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

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Correlação e análise de trilha de produtividade de grãos e seus componentes e caracteres de planta em cártamo (Carthamus tinctorius L.) e mamona (Ricinus communis L.)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inoculação e adubação molíbdica no amendoim cultivado em semeadura direta sobre forrageiras

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Morfo-anatomia de raízes tuberosas de mandioca (Manihot esculenta Crantz) cultivar IAC 576-70 em diferentes preparos do solo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comportamento produtivo do trigo em função da densidade de semeadura e da aplicação de reguladores vegetais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Alterações físicas e químicas do solo em função do sistema de produção e da aplicação superficial de silicato e calcário

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

Produção de plantas de arroz sob a ação de silício e nitrogênio

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

Mapeamento genético e identificação de marcadores aflp, microssatélites genômicos e funcionais associados a parâmetros agroindustriais em cana-de-açúcar

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização de variedades de amendoim cultivadas em diferentes populações

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)