Home Itens selecionados Provedores de dados OAI Créditos Sobre Ajuda

			Busca avançada
	Provedor de dados AgEcon (2) Autor Graybeal, Dale K. (1) Marra, Michele C. (1) Norwood, F. Bailey (1) Palavra-chave Crop Production/Industries (2) Marginal product (2) Bootstrap (1) C150 (1) C200 (1) Corn yield (1) Damage abatement (1) Nitrogen fertilizer (1) Nonlinear regression (1) Pesticide economics (1) Productivity (1) Q100 (1) Unobserved variables (1) Mais... Tipo do documento Journal Article (2) Ano 2003 (1) 2000 (1) País United States (2) Idioma Inglês (2)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 2 Primeira ... 1 ... Última VARIATION IN MARGINAL RESPONSE TO NITROGEN FERTILIZER BETWEEN LOCATIONS AgEcon Graybeal, Dale K.. A logistic growth equation with time and location varying parameters was used to model corn response to applied nitrogen. A nonlinear dummy-variable regression model provided a parsimonious representation of site and time effects on parameter values. The model was used to test for the equality of the mean marginal product of nitrogen fertilizer between locations on the coastal plain of North Carolina. Monte Carlo simulation and bootstrap simulation were used to construct finite sample covariance estimates. Results support rejection of the hypothesis that mean marginal products are equal when nitrogen is applied at 168 kg/ac. A comparison of bootstrapped errors and asymptotic errors suggests that results based on asymptotic theory are fairly reliable in... Tipo: Journal Article Palavras-chave: Bootstrap; Corn yield; Marginal product; Nitrogen fertilizer; Nonlinear regression; Crop Production/Industries; C200; C150; Q100. Ano: 2000 URL: http://purl.umn.edu/15502 Pesticide Productivity: Of Bugs and Biases AgEcon Norwood, F. Bailey; Marra, Michele C.. Pesticide productivity is both important and difficult to measure. Typically, pesticide marginal products are estimated without information on the pest pressure. Three theoretical models are developed which suggest absence of such information may cause an underestimation of pesticide productivity. Using application frequency variables as a proxy for pest populations, we show that pesticide marginal products are higher when pest pressure is accounted for. Tipo: Journal Article Palavras-chave: Damage abatement; Marginal product; Pesticide economics; Productivity; Unobserved variables; Crop Production/Industries. Ano: 2003 URL: http://purl.umn.edu/31062 Registros recuperados: 2 Primeira ... 1 ... Última

Empresa Brasileira de Pesquisa Agropecuária - Embrapa Todos os direitos reservados, conforme Lei n° 9.610 Política de Privacidade Área restrita		Embrapa Parque Estação Biológica - PqEB s/n° Brasília, DF - Brasil - CEP 70770-901 Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco