Evaluation of the grass-tanzania ("Panicum maximum") using multivariate analyses Avaliação do capim-tanzânia ("Panicum maximum") por meio de métodos de análise multivariada
The experiment was conducted with objective of evaluating the tanzania grass, using mult-trait procedures: discriminant function analysis and principal components analysis. The variables were: dry matter of leaf (DML), dry matter of the plant (DMP), nitrogen (N), phosphorous (P), magnesium (Mg), cal...
Main Authors: | , , , , , |
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Format: | Article in Journal/Newspaper |
Language: | English Portuguese |
Published: |
Universidade Federal da Bahia
2008
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Subjects: | |
Online Access: | https://doaj.org/article/d34f49e10a6444a387cd4419ada597c7 |
Summary: | The experiment was conducted with objective of evaluating the tanzania grass, using mult-trait procedures: discriminant function analysis and principal components analysis. The variables were: dry matter of leaf (DML), dry matter of the plant (DMP), nitrogen (N), phosphorous (P), magnesium (Mg), calcium (Ca) and potassium (K) in the aerial part and in the root of the grass, during the rain period. The plants were fertilized with four doses of N as bovine manure (0, 60, 120, 180 kg/ha). Main components analysis was capable to reduce the 15 original variables to 6 principal components, which the most important variables were calcium at root, potassium at leaf, potassium at plant, magnesium at leaf, phosphorous at leaf and phosphorous at root. The discriminant analysis had difficulties in classifying the fertilizer dose, especially related to the levels 60, 120 e 180 kg/ha. Foi realizado um experimento com objetivo de avaliar o capim-tanzânia, por meio da técnica de análise multivariada: análise discriminante e análise de componentes principais. As variáveis avaliadas foram: matéria seca foliar (MSF), matéria seca da planta (MSP), nitrogênio (N), fósforo (P), magnésio (Mg) e cálcio (Ca) na parte aérea e na raiz, da gramínea, realizados no período das chuvas (primavera/verão). As plantas foram adubadas com quatro doses de N na forma de chorume bovino (0, 60, 120, 180 kg/ha). A análise de componentes principais foi capaz de reduzir o número de variáveis originais de 15 para seis componentes principais, sendo que as variáveis mais importantes foram cálcio na raiz (CaR), potássio na folha (KF), potássio na planta (KP), magnésio na folha (MgF), fósforo na folha (PF) e fósforo na raiz (PR). A análise discriminante encontrou dificuldades em classificar quanto à dose de adubo, principalmente em relação às doses 60, 120 e 180 kg/ha. |
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