Influência do cultivar, do tipo de folha e do tempo de cultivo na medida indireta da clorofila (spad) em mudas de goiabeira
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Data
2009-12-01
Autores
Rozane, Danilo Eduardo [UNESP]
Souza, Henrique Antunes de [UNESP]
Prado, Renato de Mello [UNESP]
Natale, William [UNESP]
Franco, Claudenir Facincani
Leal, Renata Moreira [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Editora da Universidade Federal de Lavras (UFLA)
Resumo
A análise foliar de nitrogênio, comumente empregada em laboratórios de rotina, é destrutiva e nem sempre rápida, obstante para a tomada de decisão. Objetivou-se com a pesquisa estudar as medidas SPAD, em mudas de goiabeira (Psidium guajava L.) cultivada em solução nutritiva completa, observando-se as diferenças entre cultivares, épocas de amostragem e tipos de folhas avaliadas. O delineamento foi inteiramente casualizado, com quatro repetições, em parcelas sub-subdivididas. Assim, foi utilizada como parcela as duas cultivares de goiabeira (Paluma e Século XXI), como subparcelas os tipos de folhas (+1, +2 e +3) e, cinco épocas de amostragem ao longo do período experimental (60, 75, 90, 105 e 120 dias, após o transplantio de mudas) Concluiu-se que a leitura SPAD em mudas de goiabeira é influenciada pela cultivar, tipo de folha e época de amostragem. O terceiro par de folhas mostrou-se mais adequado para avaliar o estado nutricional do nitrogênio nas mudas de goiabeira a partir da leitura SPAD. As cultivares de goiabeira apresentaram diferença na leitura SPAD apenas aos 60 e 90 dias após o transplantio, independentemente do tipo de folha.
Foliar nitrogen analysis, also used in routine laboratories, is destructive and not always fast enough for decision making. The objective of this research was to study SPAD measurements, in guava seedlings (Psidium guajava L.) cultivated in a complete nutritive solution, observing the differences between cultivation, times of sampling, and types of evaluated leaves. The experimental design was a completely randomized scheme, with four repetitions, in split lots. The lots consisted of two guava cultivars (Paluma and Século XXI), as sub-lots, the types of leaves (+1, +2 ,and +3), and five sampling times throughout the experimental period (60, 75, 90, 105, and 120 days). It was concluded that the SPAD measurements in guava seedlings are influenced by cultivation, type of leaf, and time of sampling. The third pair of leaves was shown to be more adequate for evaluating the nutritional status of nitrogen in the guava seedlings from the SPAD reading. The guava cultivars presented differences in SPAD readings only at 60 and 90 days, regardless of the type of leaf.
Foliar nitrogen analysis, also used in routine laboratories, is destructive and not always fast enough for decision making. The objective of this research was to study SPAD measurements, in guava seedlings (Psidium guajava L.) cultivated in a complete nutritive solution, observing the differences between cultivation, times of sampling, and types of evaluated leaves. The experimental design was a completely randomized scheme, with four repetitions, in split lots. The lots consisted of two guava cultivars (Paluma and Século XXI), as sub-lots, the types of leaves (+1, +2 ,and +3), and five sampling times throughout the experimental period (60, 75, 90, 105, and 120 days). It was concluded that the SPAD measurements in guava seedlings are influenced by cultivation, type of leaf, and time of sampling. The third pair of leaves was shown to be more adequate for evaluating the nutritional status of nitrogen in the guava seedlings from the SPAD reading. The guava cultivars presented differences in SPAD readings only at 60 and 90 days, regardless of the type of leaf.
Descrição
Palavras-chave
Psidium guajava, Nutrition, Nitrogen, chlorophyll meter, Psidium guajava, Nutrição, Nitrogênio, clorofilômetro
Como citar
Ciência e Agrotecnologia. Editora da Universidade Federal de Lavras (UFLA), v. 33, n. 6, p. 1538-1543, 2009.