|
|
|
| Registros recuperados: 22 | |
|
| |
|
|
| Jane,Sérgio Alberto; Fernandes,Felipe Augusto; Silva,Edilson Marcelino; Muniz,Joel Augusto; Fernandes,Tales Jesus; Pimentel,Guilherme Vieira. |
| ABSTRACT: Assessing sugarcane (Saccharum spp.) stalk growth helps to adequately manage the phenological stages of the crop. The aim of this study was to describe the height-growth curve of four sugarcane varieties (RB92579, RB93509, RB931530 and SP79-1011), in irrigated plant-cane and ratoon cane plantations, using the Logistic and Gompertz nonlinear models, while considering all deviations from assumptions. The model parameters were estimated based on the least squares method using the Gauss-Newton algorithm. To select the most suitable model, nonlinear measures, adjusted coefficient of determination (R2 adj), residual standard deviation (RSD), and corrected Akaike information criterion (AICc) were used. Based on the best models, stalk height growth rates... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Logistic model; Gompertz model; Growth rates. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782020000300204 |
| |
|
| |
|
|
| Tur Cardona, Juan; Wailes, Eric J.; Dixon, Bruce L.; Danforth, Diana M.. |
| Multifunctional agriculture is particularly fundamental to some working lands conservation policies and programs, such as the Environmental Quality Incentive Program (EQIP), Conservation Security Program (CSP) and Wildlife Habitat Incentive Program (WHIP). Farmers can also be engaged in providing recreational and agri-tourism services such as hunting, fishing, bird-watching, farm tours, petting zoos and hospitality services. Using the Agricultural Resource Management Survey (ARMS) we analyze factors associated with participation in conservation, recreation and agri-tourism activities as a function of farm structure, farm financial measures, production practices, and socio-demographic characteristics of the farm operator. To estimate the functional... |
| Tipo: Presentation |
Palavras-chave: Multifunctional agriculture; Agri-environmental policy; Rice; Logistic model; Agricultural and Food Policy; Community/Rural/Urban Development; Crop Production/Industries; Environmental Economics and Policy; Land Economics/Use; Q18; Q26; Q28. |
| Ano: 2012 |
URL: http://purl.umn.edu/119750 |
| |
|
|
| Tur Cardona, Juan; Wailes, Eric J.; Dixon, Bruce L.; Danforth, Diana M.. |
| Multifunctional agriculture is particularly fundamental to some working lands conservation policies and programs, such as the Environmental Quality Incentive Program (EQIP), Conservation Security Program (CSP) and Wildlife Habitat Incentive Program (WHIP). Farmers can also be engaged in providing recreational and agri-tourism services such as hunting, fishing, bird-watching, farm tours, petting zoos and hospitality services. Using the Agricultural Resource Management Survey (ARMS) we analyze factors associated with participation in conservation, recreation and agri-tourism activities as a function of farm structure, farm financial measures, production practices, and socio-demographic characteristics of the farm operator. To estimate the functional... |
| Tipo: Presentation |
Palavras-chave: Multifunctional agriculture; Agri-environmental policy; Rice; Logistic model; Agricultural and Food Policy; Land Economics/Use; Q18; Q26; Q28. |
| Ano: 2012 |
URL: http://purl.umn.edu/119768 |
| |
|
|
| Rehman,Abdul; Qamar,Rafi; E. Safdar,Muhammad; ,Atique-ur-Rehman; M.R. Javeed,Hafiz; Maqbool,Rizwan; Farooq,Naila; Shahzad,Muhammad; Ali,Mazhar; H. Tarar,Zahid. |
| Abstract Background: Parthenium hysterophorus L., commonly known as parthenium weed, poses severe economic and environmental hazards to the agro-ecosystems of Pakistan. Objective: To estimate the yield loss and critical competition period of this weed in the spring sown maize crop. Method: Field studies were conducted at an agronomic research area in the College of Agriculture at the University of Sargodha in Punjab-Pakistan during two consecutive year spring seasons (2014 and 2015). Treatments were comprised of viz., control plots (weed free), and parthenium competition durations of 2, 3, 4, 5 and 6 weeks after crop emergence (WAE), as well as weedy check for the full growing season of the crop. Results: Study results showed that the prolongation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Competition duration; Parthenium; Spring maize; Yield loss; Logistic model. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582020000100327 |
| |
|
| |
|
|
| Mischan,Martha Maria; Pinho,Sheila Zambello de; Carvalho,Lídia Raquel de. |
| Growth functions with upper horizontal asymptote do not have a maximum point, but we frequently question from which point growth can be considered practically constant, that is, from which point the curve is sufficiently close to its asymptote, so that the difference can be considered non-significant. Several methods have been employed for this purpose, such as one that verifies the significance of the difference between the curve and its asymptote using a t-test, and that of Portz et al. (2000), who used segmented regression. In the present work, we used logistic growth function, which has horizontal asymptote and one inflection point, and applied a new method consisting in the mathematical determination of a point in the curve from which the growth... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nonlinear regression; Logistic model; Critical point of growth. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162011000100016 |
| |
|
| |
|
| |
|
| |
|
| |
|
|
| Miguel,José A; Melendez,Sandy J; Asenjo,Begoña; Bonilla,Luis M; Ciria,Jesús. |
| In this paper, parameters that describe growth, as a function of the season in which they were born (dry or rainy), are presented for males of the for males of the Brahman breed that were castrated at birth and raised in their native environment in the intense system of the Llano Venezolano. Data are presented for 1,478 Brahman males that were castrated at birth. Of these, 750 were born in the months of June and July (the rainy season) and 728 were born in January and February (the dry season). The animals born during the dry season were heavier up until the beginning of the fattening period; after weaning, the greatest average daily weight gain coincided in both groups during rainy periods when the pasture production was greater. When comparing the... |
| Tipo: Journal article |
Palavras-chave: Bertalanffy model; Brahman cattle; Brody model; Gompertz model; Growth curves; Logistic model; Richards model. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202012000200004 |
| |
|
|
| Amponsah, William A.; Fuller, Whitney; Gibbison, Godfrey. |
| Health disparities can be defined as differences in the health status among distinct segments of the population including differences that occur by gender, race or ethnicity, education, income, disability, or living in various geographic localities. When populations are disproportionately unhealthy, they are likely to be unable to maintain steady employment, and are more likely to rely on government assistance and support from others. We conduct a case study of three rural counties; Liberty, Long, and McIntosh to explore what factors explain the incidence of health disparities manifested in high blood pressure and heart disease. We test the hypotheses that older individuals are more likely to experience illness at a higher rate than the rest of the... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Health disparities; High blood pressure; Heart disease; Rural community; Logistic model; Community/Rural/Urban Development; Health Economics and Policy; I100; I120; I180. |
| Ano: 2010 |
URL: http://purl.umn.edu/56562 |
| |
|
|
| Zhang, Rui; Xiao, Hong-an; Zhang, Wen-xiu. |
| Factors influencing householders’ transferring out the cultivated land are analyzed from the aspects of farmers’ individual characteristics, farmers’ family features, resources endowment features and external environmental features. And based on the results of the questionnaire survey of 252 households in Chengdu City, the effect of each factor is analyzed through building the dual preference model of Logistic. The result shows that 65.87% of householders have transferred out their cultivated land and proportion of non-agricultural incomes, stability of land ownership, per capita area of cultivated farmland, comminution of cultivated farmland, transferring price and distance to town have relatively significant effect on farmers’ transferring out cultivated... |
| Tipo: Journal Article |
Palavras-chave: Cultivated land transference; Logistic model; Influence; China; Agribusiness. |
| Ano: 2011 |
URL: http://purl.umn.edu/113438 |
| |
|
|
| Carvalho,Lídia Raquel de; Pinho,Sheila Zambello de; Mischan,Martha Maria. |
| In biologic experiments, in which growth curves are adjusted to sample data, treatments applied to the experimental material can affect the parameter estimates. In these cases the interest is to compare the growth functions, in order to distinguish treatments. Three methods that verify the equality of parameters in nonlinear regression models were compared: (i) developed by Carvalho in 1996, performing ANOVA on estimates of parameters of individual fits; (ii) suggested by Regazzi in 2003, using the likelihood ratio method; and (iii) constructing a pooled variance from individual variances. The parametric tests, F and Tukey, were employed when the parameter estimators were near to present the properties of linear model estimators, that is, unbiasedness,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Logistic model; Treatments comparison. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162010000200014 |
| |
|
| |
|
|
| Janampa-Sarmiento,Peter Charrie; Takata,Rodrigo; Freitas,Thiago Mendes de; Freire,Licius de Sá; Pereira,Marcelo Menezes de Britto; Lugert,Vincent; Heluy,Guilherme Melgaço; Pereira,Marcelo Maia. |
| ABSTRACT We used five nonlinear models to calculate the weight gain of rainbow trout (122.11±15.6 g) during the final grow-out phase of 98 days under three different feed types (two commercials diets, A and B, and one experimental diet, C) in triplicate groups. We fitted the von Bertalanffy growth function with allometric and isometric scaling coefficient, Gompertz, Logistic, and Brody functions to weight (g) at age data of 900 fish, distributed in nine tanks. The equations were fitted to the data based on the least squares method using the Marquardt iterative algorithm. The accuracy of the fitted models was evaluated using a model performance metrics, combining mean squared residuals (MSR), mean absolute error (MAE), and Akaike’s Information Criterion... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aquaculture; Logistic model; Non-linear equations; Oncorhynchus mykiss. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982020000100200 |
| |
|
| |
|
|
| Beltrano,José; Ronco,Marta Guillermina; Arango,María Cecilia. |
| Water deficits cause large yield losses in wheat. Although anthesis is generally considered the most vulnerable period, water deficit during grain filling can also cause yield losses. The objective of this study was to investigate the effect of water stress and rewatering, at three different grain developmental stages, on physiological and grain filling parameters and on yield components. Wheat plants were subjected to water deficit and rewatering at the watery ripe, milk and soft dough stages. In the flag leaf, water stress decreased the relative water content, the chlorophyll and protein content and increased the leakage of solutes, at all three studied grain filling stages. Water stress at the watery ripe and milk stages reduced the final grain dry mass... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Grain filling; Growth rate; Logistic model; Protein profile; Water stress. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200011 |
| |
| Registros recuperados: 22 | |
|
|
|
