SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Flaten, Ola; Lien, Gudbrand D.; Tveteras, Ragnar.

Agriculture and aquaculture have common features associated with their biological nature affecting risk exposure of the businesses. The aim of this paper is to compare risk exposure in salmon farming and agricultural enterprises in Norway by using an implicit error component model to examine the risk structure of yields, prices and economic returns at the farm level. Results indicate a higher farm-level year-to-year variability in yields, prices and economic returns in salmon farming than in agricultural enterprises. The variability in livestock enterprises was generally lower than for crop enterprises. Return on assets was highest in salmon farming with an average annual return of 9.2%. All of the agricultural farm types exhibited a negative average...

A financial analysis of the effect of the mix of crop and sheep enterprises on the risk profile of dryland farms in south-eastern Australia

Palavras-chave: Risk analysis; Variability; Norway; Risk and Uncertainty.

Ano: 2008

URL: http://purl.umn.edu/44052

Hutchings, Timothy R.; Nordblom, Thomas L..

This study analyses the financial risk faced by representative mixed-enterprise farm businesses in four regions of south-eastern Australia. It uses discrete stochastic programming to optimise the ten-year cash flow margins produced by these farms, operating three alternative farming systems. Monte Carlo simulation analysis is used to produce a risk profile for each scenario, derived from multiple runs of this optimised model, randomised for commodity prices and decadal growing season rainfall since 1920. This analysis shows that the performance of the enterprise mixes at each site is characterised more by the level of variability of outcomes than by the mean values of financial outputs. It demonstrates that relying on mean values for climate and prices...

Tipo: Article

Palavras-chave: Farm management; Financial risk; Climate risk; Price risk; Variability; Farm Management.

Ano: 2011

URL: http://purl.umn.edu/120908

Whole farm analysis-Fertiliser nitrogen can reduce deep drainage and increase profitability

Scott, J. Fiona.

Opportunity cropping has been shown to reduce mean annual deep drainage compared to long fallow systems. A question that remained was the effect of added fertiliser nitrogen under each of the cropping systems and whether it would make a significant difference to amounts of deep drainage and to profitability. Estimates of crop yield and deep drainage results were generated using the APSLM (Agricultural Production Systems Simulator) cropping systems model, to compare long-fallow wheat/sorghum and two opportunity-cropping scenarios on a vertosol on the Liverpool Plains using rainfall data from 1958 to 1997. The results showed that fertiliser nitrogen did have a significant effect on deep drainage and gross margin under each cropping system. However, higher...

SISTEMAS ECOLÓGICOS DE PRODUÇÃO DE SEMENTES E FORRAGEM DE FEIJÃO-MIÚDO

Palavras-chave: Cropping systems; Profitability; Modelling; Variability; Whole farm budgeting; Farm Management; Land Economics/Use.

Ano: 2004

URL: http://purl.umn.edu/59705

Bevilaqua, Gilberto Antonio Peripolli; Antunes, Iraja Ferreira; Marques, Robson Luis Legorio; Maia, Manoel Souza.

A cultura do feijão-miúdo tem crescido em importância na região de clima temperado, principalmente em áreas da agricultura familiar, utilizando sistemas de base ecológica, visando a alimentação de ruminantes. Na região da planície costeira do Rio Grande do Sul a cultura apresenta grande desenvolvimento e tem se espalhado mais recentemente para outras áreas, no entanto sem informações técnicas sobre o seu manejo. A rusticidade da planta é reconhecida largamente, vegetando bem em solos mal drenados, arenosos e de baixa fertilidade, salinos e com baixa disponibilidade de água, sendo especialmente indicada como recuperadora de solo. Sua multiplicidade de usos tornou-a uma importante opção aos agricultores familiares, podendo ser utilizada além de recuperadora...

International Variability in Biofuel Trade: An Assessment of U.S. Policies

Palavras-chave: Vigna unguiculata; Fenologia; Variabilidade; Pastoreio; Leite; Fenology; Variability; Grazing; Milk; Crop Production/Industries.

Ano: 2008

URL: http://purl.umn.edu/109773

Yano, Yuki; Blandford, David; Surry, Yves R..

Although the United States has typically been in a position to import ethanol, corn-based ethanol exports are surging as the domestic market becomes saturated and world prices rise due to high prices for sugar, the competing global feedstock. The U.S. is now the world’s leading ethanol producer but domestic demand is constrained because of technical limitations in the current vehicle fleet. Higher ethanol blends have been approved for use (15% rather than 10%) but a limited number of vehicles that can use such higher blends. Infrastructure constraints also affect the potential supply of higher ethanol blends. As a result of these factors, U.S. biofuel policies can have significant implications for the world ethanol market. Usage mandates under the...

Decomposition of Variability in Farm Household Assets and Debt

Palavras-chave: Ethanol Exports; Biofuel Policies; Variability; International Relations/Trade; Resource /Energy Economics and Policy.

Ano: 2011

URL: http://purl.umn.edu/115793

Mishra, Ashok K.; El-Osta, Hisham S..

Farm families often hold large quantities of wealth and, like any other family, assess their financial progress by reviewing their net worth (or wealth) position periodically. Wealth has an impact on many decisions such as production, retirement, and succession of the farm. Households, in general, seek stability growth in wealth and, ideally, income as well. In the case of wealth, farm households will be better equipped to handle variability once the contributing sources are identified. This study measures how much of the variability in farm household assets and debt is attributed to the variability in farm and nonfarm sources of assets and farm and nonfarm sources of debt. Using a normalized variance decomposition approach and data from the Agricultural...

Tipo: Journal Article

Palavras-chave: Assets; Debt; Farm households; Variability; Variance decomposition; Farm Management; Financial Economics.

Ano: 2005

URL: http://purl.umn.edu/59682

Definitions of Biodiversity and Measures of Its Value

Effects of Site-Specific Management on the Application of Agricultural Inputs

Simpson, R. David.

The destruction of natural habitats has prompted concerns about the loss of biological diversity. Regrettably, however, there is no consensus among either biologists or economists on the most meaningful measures of biodiversity. Fundamentally different definitions are useful in asking fundamentally different questions. Considerable attention has been given to the value of diversity in search models. A measure of "aggregate variability" is appropriate to such models. Values derived from search models tend to be well behaved; they exhibit diminishing returns in diversity. In contrast, a definition of diversity as "relative abundance" is more appropriate to more complex objective functions. Values derived in these models are not necessarily well behaved. The...

Tipo: Working or Discussion Paper

Palavras-chave: Biological diversity; Biodiversity; Diversity index; Abundance; Search; Variability; Consistency; Contingent valuation; Diminishing returns; Increasing returns; Environmental Economics and Policy; D43; D83; Q20.

Ano: 2002

URL: http://purl.umn.edu/10551

Hennessy, David A.; Babcock, Bruce A.; Fiez, Timothy E..

Site-specific management of inputs in agricultural production is receiving increasing attention because of new technologies and concerns about excessive input use. This paper provides a microeconomic analysis of its implications. It shows that profit decreases with an increase in the variability of input requirements, but that the input and production effects can be quite complicated. The effects of moving from uncertainty about input requirements to variable requirements are also identified. An empirical study of nitrogen fertilization suggests that sitespecific management may reduce input use substantially, but the production and profitability impacts may not be large.

Tipo: Working or Discussion Paper

Palavras-chave: Negative externality; Site-specific management; Uncertainty; Variability; Crop Production/Industries.

Ano: 1996

URL: http://purl.umn.edu/18521

Characterization of selection effects on broiler lines using DNA fingerprinting

Rev. Bras. Ciênc. Avic.

Schmidt,GS; Hellmeister Filho,P; Zanella,EL.

The objective of this study was to evaluate the effect of selection for body weight on the genetic variability and diversity in broiler lines. Two paternal broiler lines (LL and LLc) were used. LL line was selected for 12 generations for growth and carcass and reproduction characteristics. The LLc line was established from LL line in 1985 and mated at random. Blood samples from six chickens per line were collected and used for molecular analysis. Also, a DNA pool was made for each line to compare effects between lines. Data were analyzed considering the collected information on the presence or absence of DNA bands. Band sharing scores were calculated using the DICE coefficient. The pattern of the 21 most representative bands was used. DNA fingerprinting...

Sampling strategies for tropical forest nutrient cycling studies: a case study in São Paulo, Brazil

Palavras-chave: Body weight; Fingerprinting; Molecular markers; Variability.

Ano: 2003

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2003000200005

Rev. Bras. Ciênc. Solo

Sparovek,G.; Camargo,O. A..

The precise sampling of soil, biological or micro climatic attributes in tropical forests, which are characterized by a high diversity of species and complex spatial variability, is a difficult task. We found few basic studies to guide sampling procedures. The objective of this study was to define a sampling strategy and data analysis for some parameters frequently used in nutrient cycling studies, i. e., litter amount, total nutrient amounts in litter and its composition (Ca, Mg, Κ, Ν and P), and soil attributes at three depths (organic matter, Ρ content, cation exchange capacity and base saturation). A natural remnant forest in the West of São Paulo State (Brazil) was selected as study area and samples were collected in July, 1989. The total...

Distinct genetic structure in populations of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) shown by genetic markers ISSR and COI gene

Palavras-chave: Tropical forest; Utter; Soil nutrients; Variability.

Ano: 1997

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06831997000400014

Rev. Bras. entomol.

Barbosa,Nara C. C. P.; Freitas,Sérgio de; Morales,Adriana C..

Distinct genetic structure in populations of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) shown by genetic markers ISSR and COI gene. Green lacewings are generalist predators, and the species Chrysoperla externa presents a great potential for use in biological control of agricultural pests due to its high predation and reproduction capacities, as well as its easy mass rearing in the laboratory. The adaptive success of a species is related to genetic variability, so that population genetic studies are extremely important in order to maximize success of the biological control. Thus, the present study used nuclear (Inter Simple Sequence Repeat - ISSR) and mitochondrial (Cytochrome Oxidase I - COI) molecular markers to estimate the genetic variability...

GENETIC DIVERSITY OF PASSIFLORA ACCESSIONS BASED ON MORPHOPHYSIOLOGICAL SEED DESCRIPTORS

Palavras-chave: Genetic distance; Green lacewings; Insecta; Population structure; Variability.

Ano: 2014

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0085-56262014000200012

Rev. Bras. Frutic.

MAROSTEGA,THALITA NEVES; ARAUJO,LOURISMAR MARTINS; LUZ,PETTERSON BAPTISTA DA; NEVES,LEONARDA GRILLO; BARELLI,MARCO ANTÔNIO APARECIDO.

ABSTRACT The aim of this work was to estimate the genetic divergence among Passifloraaccessions based on morphophysiological seed characteristics. Accessions were distributed in a completely randomized design, with four replicates of 25 seeds. Data were submitted to analysis of variance and the means grouped by the Scott-Knott method. The genetic diversity was studied according to the Tocher and UPGMA grouping method based on the Mahalanobis distance (D2) and Canonical Variables. In the cluster analyzes, four groups were formed by the UPGMA and Canonical Variables methods. In the Tocher Optimization method, seven groups were formed. of P. eichleriana, P. suberosa, P. edulis and P. foetida accessions presented the best results for the seed characteristics...

Plant biometrics of malay, rose and water apple

Palavras-chave: Passion fruit tree; Variability; Wild; Grouping method.

Ano: 2017

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452017000500803

Rev. Bras. Frutic.

Nacata,Guilherme; Andrade,Renata Aparecida de.

Abstract Due to the lack of studies comparing Syzygium malaccensis(L) Meer e Perry, Syzygium aqueum Burm.f. and Syzygium jambos (L) Alston Syzygium in relation to the botanical genus Sygygium regarding the physical characteristics, the present research was conducted, aiming at biometrically characterizing each of the three species, as well as comparing them. The fruits were collected from the São Paulo State University (Unesp), School of Agricultural and Veterinarian Sciences, Jaboticabal. Syzygium plants were used for the evaluation of: fruit and seed masses (g); width and length of leaves (cm) and of seeds (cm); percentage of fruit pulp; length of leaf petiole (cm); and leaf area (cm2). Fifty fruits, leaves and seeds of each species were used, with 5...

Tipo: Info:eu-repo/semantics/other

Palavras-chave: Description; Morphological characterization; Syzygium; Variability.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452018000600601

SELECTION VIA MIXED MODELS IN SEGREGATING GUAVA FAMILIES BASED ON YIELD AND QUALITY TRAITS

Rev. Bras. Frutic.

QUINTAL,SILVANA SILVA RED; VIANA,ALEXANDRE PIO; CAMPOS,BIANCA MACHADO; VIVAS,MARCELO; AMARAL JÚNIOR,ANTONIO TEIXEIRA DO.

ABSTRACT Aiming at the generation of new guava varieties with superior attributes, we conducted this study adopting the REML/BLUP procedure at individual level. Seventeen segregating guava families were evaluated in a randomized-block design with two replicates and 12 plants per plot. Families were obtained after controlled biparental pollination. The studied individuals showed high genotypic variance for fruit weight (FW), total yield (YLD), and ascorbic acid content (AAC). The heritability coefficients of the mean of progenies led to high progeny-selection accuracy for pulp yield (PY), soluble solids content (SSC), in addition to FW, YLD, and AAC; moderate accuracy for fruit acidity (FA) and SSC/FA ratio; and low accuracy for mesocarp thickness (MT) and...

Individual responses of growing pigs to threonine intake

Palavras-chave: Psidium guajava; Variability; REML/BLUP.

Ano: 2017

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452017000200802

R. Bras. Zootec.

Isola,Renan Di Giovanni; Hauschild,Luciano; Perondi,Dani; Andretta,Ines; Gobi,Jaqueline de Paula; Remus,Aline; Veira,Alini Mari.

ABSTRACT A nitrogen balance test was performed to evaluate the individual responses of growing pigs to threonine intake. Eight commercial barrows were used (body weight ranging from 15 to 20 kg). A dose-response study was performed, in which the threonine supply increased in seven equidistant steps (the seven dietary threonine levels ranged from 50 to 120% of the requirements) every three days for each pig. The levels of all other amino acids were 20% higher than the tested amino acid. Nitrogen retention as a function of threonine intake was calculated per individual and per group (NLIN and NLMixed, respectively) using a linear plateau model. The highest break point value was 42.42 g of threonine intake (the most demanding individual), whereas the lowest...

Molecular characterization of GSyV-1 and GLRaV-3 and prevalence of grapevine viruses in a grape-growing area

Palavras-chave: Amino acids; Individuals; Nitrogen retention; Requirements; Variability.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982018000100500

Moura,Cátia Jacira Martins de; Fajardo,Thor Vinícius Martins; Eiras,Marcelo; Silva,Fábio Nascimento da; Nickel,Osmar.

ABSTRACT: The aims of this study were to determine the prevalence of viruses in 119 samples from 32 grapevine cultivars, collected from nine vineyards in a specific grape-growing area in southeastern Brazil, perform a partial molecular characterization of 14 isolates of Grapevine Syrah virus 1 (GSyV-1) and Grapevine leafroll-associated virus 3 (GLRaV-3) and assess the coat protein genetic variability of these viruses. The detection of viruses was implemented by real-time RT-PCR (reverse transcription polymerase chain reaction) aiming to detect seven viruses and one viroid. With the exception of the Grapevine Cabernet Sauvignon reovirus (GCSV), the viruses and viroid that were evaluated were widespread in the sampled areas, often in high prevalence and...

Phenology and morphological diversity of sweet potato (Ipomoea batatas) landraces of the Vale do Ribeira

Palavras-chave: Vitis; Diagnosis; Variability; Incidence; Leafroll.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162018000100043

Veasey,Elizabeth Ann; Silva,Jurema Rosa de Queiroz; Rosa,Mariana Silva; Borges,Aline; Bressan,Eduardo de Andrade; Peroni,Nivaldo.

The phenotypic diversity of sweet potato (Ipomoea batatas) landraces was assessed using morphological traits, verifying how this diversity is distributed among the households and settlements of the Vale do Ribeira, Brazil. A total of 74 accessions, involving 53 landraces, collected from 30 households distributed among 18 settlements that practice traditional agriculture in the municipalities of Iguape, Ilha Comprida, and Cananeia, as well as four commercial varieties acquired in markets of Iguape and Piracicaba, were evaluated under an ex situ experimental condition in Piracicaba, SP, Brazil. Nine phenological and floral descriptors, nine morphological vegetative aerial descriptors and five storage root traits were recorded. The 14 aerial vegetative and...

Polyphasic analysis of Acidovorax citrulli strains from northeastern Brazil

Palavras-chave: Local varieties; Morphology; Phenotypic diversity; Traditional agriculture; Variability.

Ano: 2007

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162007000400013

Silva,Kirley Michele Marques; Xavier,André Silva; Gama,Marco Aurélio Siqueira; Lima,Nelson Bernardi; Lyra,Maria do Carmo Castanho Pereira; Mariano,Rosa Lima Ramos; Souza,Elineide Barbosa.

ABSTRACT Bacterial fruit blotch (BFB) of cucurbit plants is caused by Acidovorax citrulli and represents a serious concern to melon (Cucumis melo L.) growers worldwide, including those in Brazil. Thirty-four A. citrulli strains from different melon production areas of northeastern Brazil were characterized for their virulence on melon fruits and their substrate utilization and molecular profiles. Based on the analysis of BFB severity on melon fruits, the A. citrulli strains were divided into three groups, classified as mildly, moderately or highly virulent. Although host-related groups were not observed, the watermelon and ‘melão-pepino’ strains exhibited only low or moderate virulence on melon fruit. Substrate utilization profiles revealed that 94 % of...

Somaclonal variation in micropropagated Heliconia bihai cv. Lobster Claw I plantlets (Heliconiaceae)

Palavras-chave: Cucumis melo; Bacterial fruit blotch; Variability.

Ano: 2016

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000300252

Rodrigues,Paulo Hercílio Viegas.

The occurrence of somaclonal variation is described in various cultures of agronomic interest. Such variation can be of benefit in the development of new flower varieties. In this study, the occurrence of somaclonal variation in micropropagated changes of Heliconia bihai cv. Lobster Claw I was investigated. Stem apexes were introduced in MS culture media with the addition of 2.5 mg L-1 of benzylaminopure (BAP) and 500 mg L-1 of sodium cefotaxime. After selecting the apex stem, it was sub-cultivated in MS media and supplemented with 4.0 mg L-1 of BAP to induce side buds. To conduct the trial, 2,000 plants were selected and compared with plants originated from rhizomes. To calculate the percentage of the variants, the plant stature, the form and color of...

Tipo: Info:eu-repo/semantics/report

Palavras-chave: Tissue culture; Flower growing; Variability.

Ano: 2008

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000600017

More adequate probability distributions to represent the saturated soil hydraulic conductivity

Mesquita,Maria da Glória Bastos de Freitas; Moraes,Sérgio Oliveira; Corrente,José Eduardo.

The saturated soil hydraulic conductivity (Ksat) is one of the most relevant variables in studies of water and solute movement in the soil. Its determination in the laboratory and in the field yields high dispersion results, which could be an indication that this variable has a no symmetrical distribution. Adjustment of the normal, lognormal, gamma and beta distributions were examined in order to search for a probability were density function that would more adequately describe the distribution of this variable. The experiment consisted in determining the saturated hydraulic conductivity, through the constant head permeameter method, in undisturbed samples of three soils of different textures from the central western region of the São Paulo State, Brazil,...