Data/hora: 11/05/2024 12:59:34

Biblioteca(s): 	Embrapa Pecuária Sudeste.	
Tipo da produção científica: 	Artigo em Periódico Indexado	
Circulação/Nível: 	A - 2	
Data corrente: 	31/07/2012	
Data da última atualização: 	16/02/2023	
Autoria: 	SANTOS, P. M.; THORNTON, B.; CORSI, M.	
Afiliação: 	PATRICIA MENEZES SANTOS, CPPSE; BARRY THORNTON, THE JAMES HUTTON INSTITUE/ ABERDEEN; MOACIR CORSI, PROF. DO DEPARTAMENTO DE ZOOTECNIA - ESALQ/PIRACICABA.	
Título: 	Adaptation of the C4 grass Panicum maximum to defoliation is related to plasticity of N uptake, mobilisation and allocation patterns.	
Ano de publicação: 	2012	
Fonte/Imprenta: 	Scientia Agricola, v. 69, n. 5, p. 293-299, sep./oct. 2012.	
DOI: 	https://doi.org/10.1590/S0103-90162012000500002	
Idioma: 	Inglês	
Conteúdo: 	Dry mass production and persistence of Panicum maximum pastures depends on nitrogen supply. Defoliation influences N uptake and allocation patterns yet its effects on plasticity of N dynamics in P. maximum have not been investigated. Stable isotopes of N (15N) were used in order to test the hypothesis that defoliation in terms of proportion of the leaf area removed effects N mobilisation, uptake and allocation patterns in P. maximum. The plants were initially cut weekly to a height of either 0.15 m or 0.30 m for seven weeks. Eight weeks after the first defoliation, all plants were defoliated for a final time to remove 0, 25, 50, 75 or 100 % of the area of each individual leaf blade of the main tiller. Root N uptake was reduced when all leaf area was removed, but more lenient defoliation improved N uptake due to a positive effect on specific N uptake. Young leaves, side tillers and roots were the main sinks for N from root uptake. Roots of P. maximum became a net source of N for mobilisation immediately after severe defoliation. Root uptake was the main source of N for new growth in P. maximum plants. Allocation pattern of mobilised N was different from that of N derived from root uptake. It was concluded that adaptation of P. maximum to defoliation is related to plasticity of N uptake, mobilisation and allocation, but changes in N dynamics did not offset negative impacts of complete defoliation of the plants.	
Palavras-Chave: 	Clipping height; Guineagrass; Organic reserves; Tropical grass.	
Thesaurus Nal: 	regrowth.	
Categoria do assunto: 	F Plantas e Produtos de Origem Vegetal	
URL: 	http://ainfo.cnptia.embrapa.br/digital/bitstream/item/62717/1/PROCI-2012.00099.pdf	
Registro original: 	Embrapa Pecuária Sudeste (CPPSE)	
Exemplares: 	CPPSE - (21246-1) - UPA - AP - DD - PROCI-2012.00099 - SAN - 2012.00099 - DIS