Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates.
Autor(a) principal: | |
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Data de Publicação: | 2010 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) |
Texto Completo: | http://www.alice.cnptia.embrapa.br/alice/handle/doc/863616 |
Resumo: | Nitrogen and K deficiency are among the most yield limiting factors in Brazilian pastures. The lack of these nutrients can hamper the chlorophyll biosynthesis and N content in plant tissues. A greenhouse experiment was carried out to evaluate the relationship among N and K concentrations, the indirect determination of chlorophyll content (SPAD readings), nitrate reductase activity (RNO3 -) in newly expanded leaf lamina (NL) and the dry matter yield for plant tops of Mombaça grass (Panicum maximum Jacq.). A fractionated 52 factorial design was used, with 13 combinations of N and K rates in the nutrient solution. The experimental units were arranged in a randomized block design, with four replications. Plants were harvested twice. The first harvest occurred 36 days after seedling transplanting and the second 29 days after the first. Significance occurred for the interaction between the N and K rates to SPAD readings and to RNO3 - assessment taken on the NL during the first growth. Besides, RNO3 - and SPAD readings increased only with the NL N concentration, reaching the highest values of both variables up to about 25 g kg-1, but were ratively constant at higher leaf N. Significant relationships either between SPAD readings or RNO3 - activity and shoot dry mass weight were also observed. The critical levels of N concentration in the NL were, respectively, 22 and 17g kg-1 in the first and second harvest. Thus, SPAD instrument and RNO3 assessment can be used as complementary tools to evaluate the N status in forage grass. |
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Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates.Guinea GrassPastureClorofilaEstado NutricionalGramínea Forrageirachlorophyllpotassiumnitrogennutritional statusNitrogen and K deficiency are among the most yield limiting factors in Brazilian pastures. The lack of these nutrients can hamper the chlorophyll biosynthesis and N content in plant tissues. A greenhouse experiment was carried out to evaluate the relationship among N and K concentrations, the indirect determination of chlorophyll content (SPAD readings), nitrate reductase activity (RNO3 -) in newly expanded leaf lamina (NL) and the dry matter yield for plant tops of Mombaça grass (Panicum maximum Jacq.). A fractionated 52 factorial design was used, with 13 combinations of N and K rates in the nutrient solution. The experimental units were arranged in a randomized block design, with four replications. Plants were harvested twice. The first harvest occurred 36 days after seedling transplanting and the second 29 days after the first. Significance occurred for the interaction between the N and K rates to SPAD readings and to RNO3 - assessment taken on the NL during the first growth. Besides, RNO3 - and SPAD readings increased only with the NL N concentration, reaching the highest values of both variables up to about 25 g kg-1, but were ratively constant at higher leaf N. Significant relationships either between SPAD readings or RNO3 - activity and shoot dry mass weight were also observed. The critical levels of N concentration in the NL were, respectively, 22 and 17g kg-1 in the first and second harvest. Thus, SPAD instrument and RNO3 assessment can be used as complementary tools to evaluate the N status in forage grass.JOSÉ LAVRES JUNIOR, CENA/USP; JOÃO DE DEUS GOMES DOS SANTOS JUNIOR, CPAC; FRANCISCO ANTONIO MONTEIRO, ESALQ.LAVRES JUNIOR, J.SANTOS JUNIOR, J. de D. G. dosMONTEIRO, F. A.2013-08-02T23:30:52Z2013-08-02T23:30:52Z2010-10-0520102013-08-02T23:30:52Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleRevista Brasileira de Ciência do Solo, v. 34, p. 801-809, 2010.http://www.alice.cnptia.embrapa.br/alice/handle/doc/863616enginfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)instname:Empresa Brasileira de Pesquisa Agropecuária (Embrapa)instacron:EMBRAPA2017-08-16T00:28:40Zoai:www.alice.cnptia.embrapa.br:doc/863616Repositório InstitucionalPUBhttps://www.alice.cnptia.embrapa.br/oai/requestopendoar:21542017-08-16T00:28:40falseRepositório InstitucionalPUBhttps://www.alice.cnptia.embrapa.br/oai/requestcg-riaa@embrapa.bropendoar:21542017-08-16T00:28:40Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) - Empresa Brasileira de Pesquisa Agropecuária (Embrapa)false |
dc.title.none.fl_str_mv |
Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates. |
title |
Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates. |
spellingShingle |
Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates. LAVRES JUNIOR, J. Guinea Grass Pasture Clorofila Estado Nutricional Gramínea Forrageira chlorophyll potassium nitrogen nutritional status |
title_short |
Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates. |
title_full |
Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates. |
title_fullStr |
Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates. |
title_full_unstemmed |
Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates. |
title_sort |
Nitrate reductase activity and spad readings in leaf tissues of guinea grass submitted to nitrogen and potassium rates. |
author |
LAVRES JUNIOR, J. |
author_facet |
LAVRES JUNIOR, J. SANTOS JUNIOR, J. de D. G. dos MONTEIRO, F. A. |
author_role |
author |
author2 |
SANTOS JUNIOR, J. de D. G. dos MONTEIRO, F. A. |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
JOSÉ LAVRES JUNIOR, CENA/USP; JOÃO DE DEUS GOMES DOS SANTOS JUNIOR, CPAC; FRANCISCO ANTONIO MONTEIRO, ESALQ. |
dc.contributor.author.fl_str_mv |
LAVRES JUNIOR, J. SANTOS JUNIOR, J. de D. G. dos MONTEIRO, F. A. |
dc.subject.por.fl_str_mv |
Guinea Grass Pasture Clorofila Estado Nutricional Gramínea Forrageira chlorophyll potassium nitrogen nutritional status |
topic |
Guinea Grass Pasture Clorofila Estado Nutricional Gramínea Forrageira chlorophyll potassium nitrogen nutritional status |
description |
Nitrogen and K deficiency are among the most yield limiting factors in Brazilian pastures. The lack of these nutrients can hamper the chlorophyll biosynthesis and N content in plant tissues. A greenhouse experiment was carried out to evaluate the relationship among N and K concentrations, the indirect determination of chlorophyll content (SPAD readings), nitrate reductase activity (RNO3 -) in newly expanded leaf lamina (NL) and the dry matter yield for plant tops of Mombaça grass (Panicum maximum Jacq.). A fractionated 52 factorial design was used, with 13 combinations of N and K rates in the nutrient solution. The experimental units were arranged in a randomized block design, with four replications. Plants were harvested twice. The first harvest occurred 36 days after seedling transplanting and the second 29 days after the first. Significance occurred for the interaction between the N and K rates to SPAD readings and to RNO3 - assessment taken on the NL during the first growth. Besides, RNO3 - and SPAD readings increased only with the NL N concentration, reaching the highest values of both variables up to about 25 g kg-1, but were ratively constant at higher leaf N. Significant relationships either between SPAD readings or RNO3 - activity and shoot dry mass weight were also observed. The critical levels of N concentration in the NL were, respectively, 22 and 17g kg-1 in the first and second harvest. Thus, SPAD instrument and RNO3 assessment can be used as complementary tools to evaluate the N status in forage grass. |
publishDate |
2010 |
dc.date.none.fl_str_mv |
2010-10-05 2010 2013-08-02T23:30:52Z 2013-08-02T23:30:52Z 2013-08-02T23:30:52Z |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
Revista Brasileira de Ciência do Solo, v. 34, p. 801-809, 2010. http://www.alice.cnptia.embrapa.br/alice/handle/doc/863616 |
identifier_str_mv |
Revista Brasileira de Ciência do Solo, v. 34, p. 801-809, 2010. |
url |
http://www.alice.cnptia.embrapa.br/alice/handle/doc/863616 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) instname:Empresa Brasileira de Pesquisa Agropecuária (Embrapa) instacron:EMBRAPA |
instname_str |
Empresa Brasileira de Pesquisa Agropecuária (Embrapa) |
instacron_str |
EMBRAPA |
institution |
EMBRAPA |
reponame_str |
Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) |
collection |
Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) |
repository.name.fl_str_mv |
Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice) - Empresa Brasileira de Pesquisa Agropecuária (Embrapa) |
repository.mail.fl_str_mv |
cg-riaa@embrapa.br |
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1794503380427603968 |