Fecha/hora: 31/05/2024 23:05:59

Biblioteca(s): 	INIA Treinta y Tres.	
Fecha corriente: 	21/02/2014	
Fecha de la última actualización: 	11/10/2019	
Autoria: 	PÉREZ DE VIDA, F.; LACA, E.A.; MACKILL, D.J.; FERNÁNDEZ, G.; FISCHER, A.J.	
Afiliación: 	FERNANDO BLAS PEREZ DE VIDA, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay.	
Título: 	Relating rice traits to weed competitiveness an yield: a path analysis.	
Año de publicación: 	2006	
Fuente/Imprenta: 	Weed Science, 2006, v.54, p. 1122-1131	
DOI: 	10.1614/WS-06-042R.1	
Idioma: 	Inglés	
Notas: 	Article history: Received March 6, 2006 // approved August 10, 2006. Published Dec. 2006.
DOI: https://doi.org/10.1614/WS-06-042R.1	
Contenido: 	Abstract:
Resistance to herbicides in the most important weeds threatens the sustainability of California rice. Weed-competitive rice cultivars could be a low-cost and safe nonchemical addition to an integrated weed management program. Trade-offs between competitiveness and productivity and inconsistent trait expression under weedy and weed-free conditions could complicate the breeding of competitive rice cultivars. A 2-year competition experiment was conducted in the greenhouse involving eight rice cultivars and two weed competition regimes (presence or absence of late watergrass) to examine the effects of rice weed-suppressive ability and tolerance to weed competition (weed tolerance) on rice yield. Competition reduced average rice yield from 32 to 48%, and watergrass biomass from 44 to 77%. Path analysis suggested that enhancing rice weed-suppressive ability and weed tolerance while minimizing possible productivity trade-offs should promote early (12 d after seeding) growth and light-capture traits followed by moderate growth rates before heading and a vigorous grain filling period. Crop growth rate (CGR) after heading was a relevant determinant of yield (direct path: 0.82, P < 0.01) and correlated (r = 0.30, P < 0.01) with weed tolerance. Late biomass accumulation was negatively correlated with harvest index and CGR during ripening (r = ?0.46, P < 0.01); thus, late-season competitiveness can lower productivity. Rice traits conferring competitiveness were correlated across weed competition regimes (r = 0.36–0.81, P < 0.01). However, significant cultivar-by-competition and cultivar-by-year interactions suggest that selection efficiency would be greater when traits are identified under competition and in different environments. This study relates to the phenotypic expression of traits for competitiveness. Breeding competitive cultivars will require additional knowledge on trait heritability, genetic correlations with competitiveness, and on the effects of the environment upon gene expression.	
Thesagro: 	ARROZ; CULTIVOS; ECHINOCHLOA PHYLLOPOGON; ESCARDA; MALEZAS.	
Categoría del tema: 	H60 Malezas y escardas	
URL: 	http://www.ainfo.inia.uy/digital/bitstream/item/5240/1/Perez-arb-2006-1.pdf	
Registro original: 	INIA Treinta y Tres (TT)	
Ejemplares: 	TT - (32834-1) - PXI - AP - PP - PP/Weed Science/2006/54 -  -  - DIS