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Yield loss caused by huanglongbing in different sweet orange cultivars in So Paulo, Brazil

BASSANEZI, Renato Beozzo; MONTESINO, Luiz Henrique; GASPAROTO, Maria Candida Godoy; BERGAMIN FILHO, Armando; AMORIM, Lilian
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.42%
Citrus huanglongbing (HLB) reduces an affected orchard`s economic life. This work aimed to characterize yield loss due to HLB for different sweet orange cultivars and determine the relationship between disease severity and yield. Disease severity and yield were assessed on 949 individual trees distributed in 11 different blocks from sweet orange cultivars Hamlin, Westin, Pera and Valencia. In each block, plants showing a range of HLB severity levels and asymptomatic plants were selected. Total yield (weight of harvested fruit), mean weight of asymptomatic and symptomatic fruit, relative yield (symptomatic tree yield/mean yield of asymptomatic trees from the same block) and relative number of fruits (fruit number from symptomatic tree/mean number of fruits from asymptomatic trees from the same block) were determined. The weight of symptomatic fruit was lower than the weight of asymptomatic fruit, but the weights of asymptomatic and symptomatic fruit were not correlated with disease severity, indicating that the effects of HLB were restricted to symptomatic branches. The relationship of the relative yield with HLB severity can be satisfactorily described by a negative exponential model. The rates of yield decrease as a function of disease severity were similar for all assessed cultivars. A relative yield (up to 19%) was observed even for trees where disease severity was 100%. The strong linear relationship between relative number of fruits per tree and the relative yield per tree suggested that the yield reduction was due primarily to early fruit drop or lack of fruit set on affected branches.; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)

Spatio-temporal variability of sugarcane yield efficiency in the state of Sao Paulo, Brazil

Marin, Fabio Ricardo; de Carvalho, Gustavo Luis
Fonte: EMPRESA BRASIL PESQ AGROPEC; BRASILIA DF Publicador: EMPRESA BRASIL PESQ AGROPEC; BRASILIA DF
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.38%
The objective of this work was to assess the spatial and temporal variability of sugarcane yield efficiency and yield gap in the state of Sao Paulo, Brazil, throughout 16 growing seasons, considering climate and soil as main effects, and socioeconomic factors as complementary. An empirical model was used to assess potential and attainable yields, using climate data series from 37 weather stations. Soil effects were analyzed using the concept of production environments associated with a soil aptitude map for sugarcane. Crop yield efficiency increased from 0.42 to 0.58 in the analyzed period (1990/1991 to 2005/2006 crop seasons), and yield gap consequently decreased from 58 to 42%. Climatic factors explained 43% of the variability of sugarcane yield efficiency, in the following order of importance: solar radiation, water deficit, maximum air temperature, precipitation, and minimum air temperature. Soil explained 15% of the variability, considering the average of all seasons. There was a change in the correlation pattern of climate and soil with yield efficiency after the 2001/2002 season, probably due to the crop expansion to the west of the state during the subsequent period. Socioeconomic, biotic and crop management factors together explain 42% of sugarcane yield efficiency in the state of Sao Paulo.; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico

Spatio-temporal variability of sugarcane yield efficiency in the state of São Paulo, Brazil; Variabilidade espaço-temporal da eficiência produtiva da cana-de-açúcar no estado de São Paulo

Marin, Fabio Ricardo; Carvalho, Gustavo Luís de
Fonte: Embrapa Informação TecnológicaPesquisa Agropecuária Brasileira Publicador: Embrapa Informação TecnológicaPesquisa Agropecuária Brasileira
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.38%
The objective of this work was to assess the spatial and temporal variability of sugarcane yield efficiency and yield gap in the state of São Paulo, Brazil, throughout 16 growing seasons, considering climate and soil as main effects, and socioeconomic factors as complementary. An empirical model was used to assess potential and attainable yields, using climate data series from 37 weather stations. Soil effects were analyzed using the concept of production environments associated with a soil aptitude map for sugarcane. Crop yield efficiency increased from 0.42 to 0.58 in the analyzed period (1990/1991 to 2005/2006 crop seasons), and yield gap consequently decreased from 58 to 42%. Climatic factors explained 43% of the variability of sugarcane yield efficiency, in the following order of importance: solar radiation, water deficit, maximum air temperature, precipitation, and minimum air temperature. Soil explained 15% of the variability, considering the average of all seasons. There was a change in the correlation pattern of climate and soil with yield efficiency after the 2001/2002 season, probably due to the crop expansion to the west of the state during the subsequent period. Socioeconomic, biotic and crop management factors together explain 42% of sugarcane yield efficiency in the state of São Paulo.

Ferrugem asiática da soja: relações entre o atraso do controle químico, rendimento, severidade e área foliar sadia de soja (Glycine max L. Merril); Asian soybean rust: relationship between delay of chemical control, yield, severity and healthy leaf area of soybean (Glycine max L. Merril)

Calaça, Helen Alves
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/01/2008 PT
Relevância na Pesquisa
36.4%
O controle da ferrugem asiática é altamente dependente do tratamento com fungicidas. A decisão do momento correto da aplicação é fundamental para a eficiência do tratamento, visto que atrasos na efetuação do controle podem torná-lo tão ineficaz quanto à ausência de aplicações. O dano provocado pela ferrugem asiática é decorrente da redução da área foliar, devido à destruição do tecido vegetal e desfolha precoce. Tendo em vista a influência que o atraso no controle tem sobre a ferrugem asiática, e esta sobre a folhagem das plantas de soja, o dano pode ser melhor compreendido com o uso de variáveis que captem modificações na área foliar do hospedeiro. Com os objetivos de avaliar o efeito do atraso no controle da ferrugem asiática sobre o rendimento e os componentes do rendimento, a duração (HAD), a absorção da área foliar sadia (HAA) de plantas de soja e sobre a severidade da doença e examinar as relações entre o rendimento de soja com a duração, absorção da área foliar sadia e severidade da ferrugem asiática, foram conduzidos cinco experimentos no Centro de Pesquisa e Desenvolvimento Agrícola da Arysta LifeScience, em Pereiras-SP. Os experimentos envolveram um tratamento preventivo e tratamentos que corresponderam a atrasos crescentes na efetuação do controle químico. As relações entre os parâmetros citados acima foram avaliadas por meio de testes de comparação de médias (LSD) e regressões lineares e não lineares (p<=0...

Probabilidade de redução relativa da produtividade do milho por ocorrência de déficit hídrico em função de datas de plantio na região de Piracicaba, SP; Probability of relative yield decrease in corn crop caused by water deficits in function of different sowing dates, in Piracicaba region, SP, Brazil

Nangoi, Indriati Ilse
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/02/2010 PT
Relevância na Pesquisa
36.4%
O déficit hídrico é uma das principais causas de perdas de produtividade agrícola. No Brasil, algumas regiões sofreram reduções elevadas na produção de milho (Zea mays L.), provocadas por estiagens, por exemplo, nas safras de 1995/1996, 1996/1997, 1998/1999, 1999/2000, 2004/2005. Para contornar ou minimizar situações de limitação hídrica é importante o planejamento da época de cultivo para melhor aproveitamento das condições climáticas locais e eficiência do manejo da lavoura. O presente trabalho objetivou subsidiar o planejamento de plantio do milho na região de Piracicaba, São Paulo, estimando a probabilidade de quebra de produtividade de cultivares de ciclo médio em decorrência do déficit hídrico, em função de datas de semeadura simuladas para o primeiro dia de cada decêndio entre setembro e fevereiro. Para isso, foi utilizado o modelo de balanço hídrico de Thornthwaite e Mather (1955) modificado por Barbieri et al. (2003), pelo qual é possível considerar a variação da capacidade de água disponível no solo ao longo do ciclo, acompanhando o crescimento do sistema radicular e representando de forma mais aproximada a situação real de armazenamento de água no solo do que o uso de um só valor de CAD ao longo do ciclo da cultura. Foram calculadas deficiências hídricas decendiais...

Interações em sistema silvipastoril: microclima, produção de forragem e parametrização de modelo para estimativa da produtividade de pastagens de Brachiaria; Interactions in a silvopastoral system: microclimate, pasture production, and yield model parameterisation for Brachiaria

Bosi, Cristiam
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 20/01/2014 PT
Relevância na Pesquisa
36.39%
Os sistemas silvipastoris (SSPs) buscam maior sustentabilidade, aliando, para isto, os componentes animal, planta forrageira e árvore. Entretanto, esta associação modifica o sistema, alterando o microclima, o crescimento das plantas e a produção animal. O presente estudo objetivou avaliar as alterações no microclima em um SSP sob pastejo, em São Carlos, SP, provocadas pela inserção das árvores, correlacionar isto com as características e a produtividade da forrageira Brachiaria decumbens e parametrizar o modelo da zona agroecológica da FAO (FAO-MZA) para estimar a produtividade de Brachiaria brizantha a pleno sol e, posteriormente, de B. decumbens em SSP. Para tanto, foram monitoradas continuamente variáveis microclimáticas por meio de quatro estações meteorológicas, distribuídas em diferentes posições dentro do sistema: a 2 metros do renque leste (2mL); a 6 metros do renque leste (6mL); a 6 metros do renque oeste (6mO); e a 2 metros do renque oeste (2mO), de forma a avaliar o microclima e a produtividade ao longo de um transecto entre os dois renques de árvores, além de uma estação a pleno sol, como referência. Concomitantemente, foram realizadas avaliações das características biométricas e da produtividade da planta forrageira durante sete ciclos com duração de 35 dias. Ao longo de cada um desses ciclos foram feitas cinco avaliações para monitorar a dinâmica de crescimento da pastagem. Essas informações foram empregadas na parametrização do modelo FAO-MZA para a estimativa da produtividade da B. decumbens e da B. brizantha. Os resultados demonstram que as variáveis microclimáticas foram modificadas pela presença das árvores...

Evaluation of Maize Yield Spatial Variability based on Field Flow Density

Marques da Silva, José Rafael; Silva, Luis Leopoldo
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica Formato: 9299 bytes; application/pdf
ENG
Relevância na Pesquisa
36.43%
Maize yield is affected by water availability, which varies with field topography. The analysis of yield data obtained in different field landscape positions allows the spatial patterns of crop yield to be identified and related to field attributes, helping the spatial management of fields to be improved. The relationship between distance to flow accumulation lines (DFL) and spatial variability of yield and grain moisture at harvest has already been identified in a previous work by the authors. The main objective of this study is to confirm the relationship between DFL and spatial variability of yield and grain moisture at harvest, and also to establish a relationship between a field hydrological attribute (flow density) and average yield and distance to nearest flow accumulation line. The study was conducted using data collected from three agricultural fields (30,40 and 60 ha) irrigated by centre-pivot systems, in Southern Portugal, over a 3 yr period from 2002 to 2004.Collected data were divided into data sets corresponding to nine classes of DFL. Total flow lines length (SFLL) was used to calculate flow density (Fd). Based on these data sets, the relationship between yield and grain moisture at harvest and DFL and flow density was analysed. Coefficients of determination were very high (significant R2 from 0.91 to 0.98) for almost every year of the experiment...

Evaluation of the relationship between maize yield spatial and temporal variability and different topographic attributes

Marques da Silva, José Rafael; Silva, Luis Leopoldo
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica Formato: 6908 bytes; application/pdf
ENG
Relevância na Pesquisa
36.39%
Maize yield data were collected in seven agricultural fields irrigated by centre-pivot irri-gation systems, in Southern Portugal, from 2002 to 2004. These data were then correlated with different primary and secondary topographic attributes. The attained correlation coefficients were used to evaluate the relationship between yield spatial variability and each individual topographic attribute. In this three-year period applied water was always lower than crop water requirements. The increase of applied water in 2004 resulted in an improvement in average yield and especially in yield spatial stability. Average yield showed a strong dependency on topography, with high correlation coefficients between yield and elevation and slope. It presented also a high correlation with topographic indices that reflect field water availability, such as the wetness index and distance to flow accumulation lines (DFL). The DFL index was the topographic index with higher correlation coefficients with yield. The negative coefficients of correlation between yield and DFL, attained in most fields in the three-year study period, show that, in general, yield increases with the decrease of DFL, i.e., with the increase of water availability. In undulating land areas flow lines are very abundant...

The yield pattern considering the distance to flow accumulation lines

Marques da Silva, José Rafael; Silva, Luis Leopoldo
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica Formato: 6240 bytes; application/pdf
ENG
Relevância na Pesquisa
36.38%
Precision agriculture techniques imply a spatial management of fields and to do so a good understanding of the spatial and temporal variability of yield is needed. Average yield data from seven irrigated maize fields were used to study the yield pattern considering the distance of plants to flow accumulation lines. It was found that there is a significant correlation between average yield and distance to flow accumulation lines (DFL). This correlation is best represented by a polynomial function. The most common shape of the yield pattern curve considering the distance to flow accumulation lines shows that there is an increase in average yield with DFL from 0 to 12.5–17.5 m. Near the flow lines the average yield presents lower values due to drainage problems causing plant growth problems. It was also observed higher yield variability near the flow lines. For higher distances from the flow lines there is a continuous decrease in average yield due to less water availability and other variations of soil properties.

Yield potential probability maps using the Rasch model

Marques da Silva, José Rafael; J. Rebollo, Francisco; Sousa, Adélia; Mesquita, Paulo
Fonte: ELSEVIER Publicador: ELSEVIER
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
36.42%
Yield monitors commonly show that there are very large yield differences within a field which often differ from year to year. Because our ability to estimate reductions in growth and to quantify yield losses resulting from complex interactions and multiple stresses is limited, it does not appear feasible to analyse yield variability using a point to point strategy. For a farmer it is important to select parcels of land, or parts of a parcel, with a high yield probability. To analyse the high yield probability zones the Rasch model is used considering a multi-temporal yield data set. The Rasch measure for multi-temporal yield data makes it possible to place on a continuum axis the yield samples considered in terms of annual yield and vice versa. Using the Rasch measurement one can produce yield potential probabilistic maps taking into account each sample coordinate. From a quantitative point of view it is possible to find yield samples that do not support the model, or which do not reach the expected levels. Positive and negative mismatches can be analysed individually or according to a particular year yield. Thus, the Rasch model makes it possible to systematise the data, making it an effective tool for making appropriate decisions regarding areas with higher yield performance and greater stability over time. Also...

The yield pattern considering the distance to flow accumulation lines

Marques da Silva, José Rafael; Silva, Luis Leopoldo
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.39%
Precision agriculture techniques imply a spatial management of fields and to do so a good understanding of the spatial and temporal variability of yield is needed. Average yield data from seven irrigated maize fields were used to study the yield pattern considering the distance of plants to flow accumulation lines. It was found that there is a significant correlation between average yield and distance to flow accumulation lines (DFL). This correlation is best represented by a polynomial function. The most common shape of the yield pattern curve considering the distance to flow accumulation lines shows that there is an increase in average yield with DFL from 0 to 12.5–17.5 m. Near the flow lines the average yield presents lower values due to drainage problems causing plant growth problems. It was also observed higher yield variability near the flow lines. For higher distances from the flow lines there is a continuous decrease in average yield due to less water availability and other variations of soil properties.

Fitting the term structure of yield spreads

Rodrigues, Velma de Jesus
Fonte: Instituto Superior de Economia e Gestão Publicador: Instituto Superior de Economia e Gestão
Tipo: Dissertação de Mestrado
Publicado em //2014 ENG
Relevância na Pesquisa
36.39%
Mestrado em Finanças; O objetivo deste estudo é a extracção e análise da estrutura temporal da curva de Yield Spread no contexto das Obrigações de Tesouro emitidas por Portugal entre Janeiro 2004 e Junho de 2014, período no qual Portugal enfrentava uma crise de liquidez e de dívida. Para a extracção da curva de Yield Spread utilizamos o disjoint method. Este método requer uma curva teoricamente sem risco e uma curva com risco: como curva sem risco utilizamos a curva estimada pelo ECB e a curva com risco é estimada pelo modelo de Nelson-Siegel (1987). Dada a importância do papel da previsão no conhecimento da evolução da estrutura temporal, o objetivo secundário deste projeto é a previsão da curva das yields através da previsão dos parâmetros do modelo de Nelson-Siegel (1987) utilizando como o modelo de referência o processo passeio aleatório com deriva e como modelos competidores os AR(1) e VAR(1). Os resultados incluem a análise empírica da curva de yield spread das Obrigações de Tesouro de Portugal e, relativamente à previsão da curva das yields, concluímos que o AR(1) e VAR(1) produzem resultados ligeiramente melhores que o modelo de referência e que esses resultados melhoram à medida que o horizonte temporal da previsão aumenta.; This study aims to fit and analyze the behaviour of the Yield Spread curve in the context of Portugal Government Bonds...

Fifty years of wheat breeding in Southern Brazil: yield improvement and associated changes

Rodrigues,Osmar; Lhamby,Julio César Barreneche; Didonet,Agostinho Dirceu; Marchese,José Abramo
Fonte: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira Publicador: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2007 EN
Relevância na Pesquisa
36.38%
The objective of this study was to assess the impact of genetic breeding on grain yield, and to identify the physiological traits associated to the increment in yield and their related growth processes, for wheat cultivars grown in Southern Brazil, in the past five decades. Seven wheat cultivars released between 1940 and 1992, were compared for physiological aspects associated with grain yield. Grain yield, biological yield, biomass partitioning, harvest index and grain yield components were also determined. The number of grains per square meter was more affected by plant breeding and was better correlated with grain yield (r = 0.94, p<0.01) than with grain weight (r = -0.39ns). The higher number of grains per square meter was better correlated with the number of grains per spike in the modern cultivars than in the older ones. The genetic gain in grain yield was 44.9 kg ha-1 per year, reflecting important efforts of the breeding programs carried out in Southern Brazil. Grain yield changes, during the period of study, were better associated with biomass production (r = 0.78, p<0.01) than with harvest index (r = 0.65, p<0.01).

Produtividade e teor de óleo para genótipos de soja em três épocas de semeadura; Yield and oil contents in soybean genotypes in three sowing dates

Lélis, Marcelo Magri
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Dissertação
POR
Relevância na Pesquisa
36.42%
A época de semeadura é um dos fatores que mais influencia no desempenho da soja (Glycine max (L.) Merrill), em função de alterações nas variáveis climáticas das quais a cultura é sensível. Objetivou-se estudar o efeito de três épocas de semeadura na produtividade e no teor de óleo para genótipos de soja, nas condições de Uberlândia- MG. O delineamento foi o de blocos casualizados, em esquema de parcela subdividida, com três repetições. As parcelas foram atribuídas às épocas de semeadura (31/10, 22/11 e 14/12/06) e as subparcelas aos genótipos (Impacta, Guarani, Riqueza, Milionária, Xavante, UFU-6, UFU-7, UFU-8, UFU-9, UFU- 10, Conquista e Garantia). A unidade experimental (parcela) casualizada foi composta pelos genótipos dispostos também de forma casualizada. A subparcela foi constituída por uma fileira de semeadura de 5 m, aproveitando-se os 4 m centrais. Foram avaliados: cor de flor, número de dias para floração (NDF), altura da planta na floração (APF), altura da planta na maturação (APM), “stand”, retenção foliar (RF), acamamento (ACM), altura de inserção da primeira vagem (AIPV), severidade de ferrugem (SF), peso de 100 grãos (PCG) e produtividade. Quanto ao teor de óleo, foram considerados somente os genótipos Impacta...

Genetic dissection of grain yield in bread wheat. I. QTL analysis

Kuchel, H.; Williams, K.; Langridge, P.; Eagles, H.; Jefferies, S.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
Relevância na Pesquisa
36.45%
Grain yield forms one of the key economic drivers behind a successful wheat (Triticum aestivum L.) cropping enterprise and is consequently a major target for wheat breeding programmes. However, due to its complex nature, little is known regarding the genetic control of grain yield. A doubled-haploid population, comprising 182 individuals, produced from a cross between two cultivars ‘Trident’ and ‘Molineux’, was used to construct a linkage map based largely on microsatellite molecular makers. ‘Trident’ represents a lineage of wheat varieties from southern Australia that has achieved consistently high relative grain yield across a range of environments. In comparison, ‘Molineux’ would be rated as a variety with low to moderate grain yield. The doubled-haploid population was grown from 2002 to 2005 in replicated field experiments at a range of environments across the southern Australian wheat belt. In total, grain yield data were recorded for the population at 18 site-year combinations. Grain yield components were also measured at three of these environments. Many loci previously found to be involved in the control of plant height, rust resistance and ear-emergence were found to influence grain yield and grain yield components in this population. An additional nine QTL...

Effect of climate and cultural practices on grapevine flowering and yield components.

McLoughlin, Suzanne Jean
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2009
Relevância na Pesquisa
36.42%
This thesis presents results from two separate studies. First, the impact of bearer length on yield components within the canopy was investigated in season 2005/06, on a commercially-managed, mechanically-pruned vineyard of Vitis vinifera L. Cabernet Sauvignon in Coonawarra, South Australia. Pruning resulted in the retention of bearers with 1-7 nodes, with the weighted average bearer length being two nodes for the canopy. As bearers of one to five nodes in length were the most common, these were studied. Yield components (on a per shoot basis) were analysed according to the node position on the bearer at which the shoot arose. Both budburst and inflorescence number per node were highest at the distal node positions on each length bearer, even if the nodes were at the same positions from the base of the bearer and would normally be expected to have similar fertility. Budburst appeared to act by modifying inflorescence number per node based on the relative location of each node from the apex of the bearer. Shoots that arose from the most distal node positions had the highest flower number per inflorescence and berry number per bunch. Flower number per inflorescence was significantly higher on two-inflorescence shoots than single-inflorescence shoots. The relationship between bunch size and node position...

The genetics of oil yield in Melaleuca alternifolia and Eucalyptus loxophleba

Webb, Hamish Oscar
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Thesis (PhD)
EN
Relevância na Pesquisa
36.4%
Genetic improvement of essential Myrtaceae based oil crops is vital to the long-term health and profitability of Australian essential oil industries. Improving oil yield and efficiency is an important part of maintaining the competitive advantage that Australian industries currently hold over international competitors. Over the last 20 years, gains in oil yield have been made through the tea tree breeding programme, which has helped the industry get to where it is today. This work needs to continue to advance, for the health of the industry into the future. Using molecular techniques to facilitate this is the best way forward for the industry. To better understand how oil yield is controlled in both tea tree (Melaleuca alternifolia) and York gum (Eucalyptus loxophleba) within Australia, I first investigated whether gene expression had an effect on oil yield in M. alternifolia. In this study I investigated the transcript abundance of 13 genes (dxr, dxs2, dxs3, cmk, mcs, mct, hds, mvk, hmgs1, pmd1, ippi1, ippi2 and gpps) in 48 individuals that varied in oil yield. The expression of all genes in the pathway explained 87% (R2 = 0.87) of variation in oil yield, These result are important in that they show that oil yield isnʼt just controlled by one or two genes in the biosynthetic pathway...

Factors controlling sediment yield in a major South American drainage basin: the Magdalena River, Colombia

Restrepo, Juan D.; Kjerfve, Bjo¨rn; Hermelin Arbaux, Michel; Restrepo, Juan C.
Fonte: Elsevier; Grupo de Investigación Geología Ambiental e Ingeniería Sísmica; Escuela de Ingeniería Publicador: Elsevier; Grupo de Investigación Geología Ambiental e Ingeniería Sísmica; Escuela de Ingeniería
Tipo: article; Artículo; publishedVersion
ENG
Relevância na Pesquisa
36.39%
The Magdalena River, a major fluvial system draining most of the Colombian Andes, has the highest sediment yield of any medium- sized or large river in South America. We examined sediment yield and its response to control variables in the Magdalena drainage basin based on a multi-year dataset of sediment loads from 32 tributary catchments. Various morphometric, hydrologic, and climatic variables were estimated in order to understand and predict the variation in sediment yield. Sediment yield varies from 128 to 2200 t kmK2 yrK1 for catchments ranging from 320 to 59,600 km2. The mean sediment yield for 32 sub-basins within the Magdalena basin is w690 t kmK2 yrK1. Mean annual runoff is the dominant control and explains 51% of the observed variance in sediment yield. A multiple regression model, including two control variables, runoff and maximum water discharge, explains 58% of the variance. This model is efficient (MEZ0.89) and is a valuable tool for predicting total sediment yield from tributary catchments in the Magdalena basin. Multiple correlations for those basins corresponding to the upper Magdalena, middle basin, Eastern Cordillera, and catchment areas greater than 2000 km2, explain 75, 77, 89, and 78% of the variance in sediment yield...

GRAIN YIELD AND YIELD COMPONENTS BY SOYBEAN CANOPY STRATUM IN RESPONSE TO PLANT ARRANGEMENT AND WATER AVAILABILITY; RENDIMENTO DE GRÃOS DA SOJA E SEUS COMPONENTES POR ESTRATO DO DOSSEL EM FUNÇÃO DO ARRANJO DE PLANTAS E REGIME HÍDRICO

RAMBO, Lisandro; COSTA, José Antonio; PIRES, João Leonardo Fernandes; PARCIANELLO, Geovano; FERREIRA, Felipe Gutheil
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares Formato: application/pdf
Publicado em 07/06/2005 ENG
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Plant arrangement that allow better plant distribuition in the area results in larger grain yield. This increase might be the result of diferential contribution of canopy strata for yield determination. The experiment was performed at Agronomic Experimental Estation of the Universidade Federal do Rio Grande do Sul, in Eldorado do Sul, Rio Grande do Sul, Brazil, in the 2000/01 growing season. The objectives were to evaluate grain yield and yield components by stratum of soybean canopy in different plant arrangements, under two water availability. Tested cultivar was BRS 137 (early, determinate), in no-till planting. Treatments arrangements were split-splitplot randomized complete-block design, with four replications. Water availability (irrigate and no irrigated), row spacing (20 and 40 cm) and population levels (20, 30 and 40 plants.m-2) were tested. Grain yield and yield components, by soybean canopy stratum, were determined in samples of ten plants, in sequence in the row, in each sub-subplot. Grain yield was incresead by irrigation and was detected interaction between row spacing and plant population. Plant arrangememnt of 20 cm row spacing and population of 20 plants.m-2 resulted in greater grain yield. There was a linear decrease in grain yield with the increase in population...

Grain yield and yield components of triticale upon application of different foliar fertilizers

Kinaci,Engin; Gulmezoglu,Nurdilek
Fonte: ASOCIACIÓN INTERCIENCIA Publicador: ASOCIACIÓN INTERCIENCIA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2007 EN
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Field experiments were conducted in the growing seasons of 2000-2001 and 2001-2002 to investigate the effects of various commercial foliar fertilizers containing N, P, K and micro nutrients on yield and yield components of triticale. Yield and yield component values were different among years because of dry season. The results revealed that foliar treatments had significant positive effect on grain yield, spikelet number per spike, number of grain per spike, 1000 grain weight and harvest index in both years. The most effective foliar fertilizer on yield and yield components during drought stress was Zn-15, a chelated (EDTA) form of zinc. Both NZN and ZnSO4 increased grain yield of triticale under no stress conditions.