Data/hora: 21/09/2024 13:42:37

Biblioteca(s): 	Embrapa Agrobiologia.	
Data corrente: 	24/11/2003	
Data da última atualização: 	24/11/2003	
Autoria: 	ARAÚJO, A. P.; TEXEIRA, M. G.	
Título: 	Nitrogen and phosphorus harvest indices of common bean cultivars: Implications for yield quantity and quality.	
Ano de publicação: 	2003	
Fonte/Imprenta: 	Plant and Soil, Dordrecht, v. 257, p. 425-433, 2003.	
Idioma: 	Inglês	
Conteúdo: 	Breeding for yield in common bean (Phaseolus vulgaris L.) should consider the efficiency of biomass and nutrient partitioning to grains. In field experiments, 9 and 18 bean cultivars were cultivated in 1998 and 1999, respectively, to identify the genotypic variability of harvest index (Hl) and N and P harvest indices (NH1 and PH1), and to evaluate the relationships between these indices and grain yield. Cultivars differed for grain yield, Hl, NH1 and PH1 in both years, but these indices varied less than grain yield. Growth habit markedly influenced HI, with prostrate cultivars possessing higher Hl, NH1 and PH1 than erect cultivars; hence selection for HI should be performed within each phenological group. Grain yield was strongly associated with grain N and P contents, and positively but weakly correlated to H1, NH1 and PH1; the indices were highly correlated among themselves. Multiple-regression analysis showed that most genotypic variation of grain yield was associated with the amount of N and P accumulated by the crop at maturity, and some yield variation was associated with seed nutrient concentration, particularly P concentration, whereas NH1 and PH1 had a minor role. Combined analysis of both experiments showed that grain yield diminished by 57% from 1998 to 1999, whereas Hl remained almost stable and NH1 and PH1 decreased slightly, but the significant year x cultivar interaction revealed different degrees of phenotypic plasticity of biomass partitioning among cultivars. Selection solely for increased H1 would scarcely result in improved grain yield, raising concomitantly NH1 and PH1 and probably reducing grain P concentration. 

Palavras-Chave: 	N; P.	
Thesagro: 	Feijão; Fósforo; Nitrogênio; Phaseolus Vulgaris; Variação Genética.	
Thesaurus Nal: 	beans; genetic variation; nitrogen; phosphorus.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Agrobiologia (CNPAB)	
Exemplares: 	CNPAB - (28252-1) - UPC - SP - -- -  -  - 22505 - DIS