Data/hora: 09/06/2024 23:15:59

Biblioteca(s): 	Embrapa Soja.	
Data corrente: 	16/12/2008	
Data da última atualização: 	26/07/2017	
Autoria: 	KUMUDINI, S.; GODOY, C. V.; BOARD, J. E.; OMIELAN, J.; TOLLENAAR, M.	
Afiliação: 	University of Kentucky; CLAUDIA VIEIRA GODOY, CNPSO; University Baton Rouge; University of Kentucky Lexington; University of Guelph.	
Título: 	Mechanisms involved in soybean rust-induced yield reduction.	
Ano de publicação: 	2008	
Fonte/Imprenta: 	Crop Science, v. 48, n. 6, p. 2334-2342, Nov./Dec. 2008	
ISBN: 	10.2135/cropsci2008.01.0009	
Idioma: 	Inglês	
Conteúdo: 	Soybean rust (SBR; caused by Phakopsora pachyrhizi Syd. and P. Syd.) leads to premature leaf loss and yield reduction. The objectives of this study were to assess effects of SBR infection on soybean [Glycine max (L.) Merrill] yield and to identify causes for the yield reduction. Experiments were conducted in the 2005-2006 and 2006-2007 growing seasons at Londrina, Brazil. The five treatments were SBR infection beginning at either (i) the R2 or (ii) R5 growth stages; nondiseased defoliation treatments to mimic the leaf loss when SBR started at either (iii) the R2 or (iv) R5 growth stages; and (v) a disease-free, nondefoliated control. The control and defoliation treatments were protected against SBR by fungicide applications. Disease severity, lesion area, and leaf area were monitored from R2 to R7. Biomass and seed yield were measured at maturity. Mean SBR-induced yield reductions were 67% when infection started at R2 and 37% when infection started at R5. Leaf loss alone reduced yield significantly in only one year and only when defoliation treatments were begun at R2 (31% in 2005-2006). Soybean rust-induced yield loss was attributable to (i) premature leaf loss, (ii) reduction in canopy green leaf area due to SBR lesions, (iii) reduction in dry matter accumulation per unit absorbed radiation by the nonlesion green leaf area, and (iv) reduction in harvest index. The response of harvest index was attributable to reduced seed set and seed mass resulting likely from SBR-induced reductions in rate of dry matter accumulation.	
Palavras-Chave: 	Ferrugem da soja.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Soja (CNPSO)	
Exemplares: 	CNPSO - (28731-1) - UPC - AP - PP - 11173 -  - 11173 - DIS