Estudos sobre a nutrição mineral do sorgo granífero: VII absorção de sulfato marcado por raizes destacadas

Studies on the mineral nutrition of grain sorghum: VII sulfate uptake by excised roots

Resumos

Some aspects of SO4² absorption by excised roots of "Sorghum bicolor (L.) Moench" namely, inibition effects of NaF, KCN, 2,4- DNP and factors such as aeration, solution pH and temperature on the rate of absorption were studied. The excised roots showed multiphasic mecanism of SO4²- absorption. The relative absorption rates, presented by three varieties, were in decreasing order: Tey-101, Contibrasil-101 and Dekalb-E-57. Inhibition effects on the absorption of SO4²- by excised roots were shown in the case of the three ihibitors studied hereof-. Aeration and solution temperature are important factors on SO4²- absorption. At the external solutio n concentration of Na,2SO(4)10-³M the best fitted equation to the experimental values was shown to be: umoles/g dry matter = 1,639- 1,585 exp. (-0,006618t)

Estudos sobre a nutrição mineral do sorgo granífero. VII absorção de sulfato marcado por raizes destacadas(^*)

Studies on the mineral nutrition of grain sorghum, VII sulfate uptake by excised roots

E. Malavolta^I; C.O. Ponchio^I, F.A. Monteiro, G.M.A. Silva^I; J.C. Chitolina^I; F.D. Nogueira^I; P.A. Jaha^I; R.M. Del Giudice^I; V.L..G Assis^I; A.C.P. Aguirre^I; A.A. Caetano^I; L.L.C. Garcia^I; E. Matsui^I; E.C.S. Dantas^I; L.C. Castanheira^I; E. Santos^I; A.N. Gonçalves^I; B.F. Faganello^I; M. Moraes^I; S.M. Cicero^II

^IDepartamento de Química e CENA, ESALQ, Piracicaba

^IIEstudantes pós graduados de Solos & Nutrição de Plantas

RESUMO

Um estudo da absorção de sulfato por raizes destacadas de sorgo granífero mostrou: mecanismo (ou sítios) múltiplo para absorção; o tamanho do espaço livre aparente; a influência da temperatura, pH; a dependência da atividade metabólica.

SUMMARY

Some aspects of SO₄² absorption by excised roots of "Sorghum bicolor (L.) Moench" namely, inibition effects of NaF, KCN, 2,4- DNP and factors such as aeration, solution pH and temperature on the rate of absorption were studied.

The excised roots showed multiphasic mecanism of SO₄²- absorption. The relative absorption rates, presented by three varieties, were in decreasing order: Tey-101, Contibrasil-101 and Dekalb-E-57. Inhibition effects on the absorption of SO₄²- by excised roots were shown in the case of the three ihibitors studied hereof-. Aeration and solution temperature are important factors on SO₄²- absorption.

At the external solutio n concentration of Na,₂SO₄10-³M the best fitted equation to the experimental values was shown to be:

umoles/g dry matter = 1,639- 1,585 exp. (-0,006618t)

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LITERATURA CITADA

Entregue para publicação em 22-12-1977.

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*

Com ajuda do BNDE (FUNTEC 293), FAPESP, CNEN, CAPES & CNPq

Datas de Publicação

• Publicação nesta coleção
  17 Maio 2012
• Data do Fascículo
  1977