Field screening of diverse rice genotypes for weed competitiveness in irrigated lowland ecosystems

摘要: Abstract Weeds cause considerable yield losses in irrigated rice West Africa, particularly where sub-optimal crop management or limited resources hamper production. Because of the recent focus regional breeding programs Africa on a wide diversity interspecific (O. sativa indica×O. glaberrima) and intraspecific sativa×O. sativa) crosses for lowland systems, new genotypes with promising potential putatively improved weed competitiveness are now available. Our study intended to establish screening methodology lowlands, evaluate competitive abilities diverse genotypes, relate several morphological plant characteristics abilities. A selection 25 cultivars advanced lines was grown under conditions during 2000 wet season (WS) 2001 dry (DS) at Ndiaye (Senegal), their reaction four different competition levels assessed. Competition greatest test were mixture an O. indica cultivar natural growth. Average across 36% WS 31% DS, but differences between highly significant both seasons ranged from 0 84%. Competitive not related yields without competition. In combined high good outperformed currently widely used check variety. Height, tiller density, specific leaf area (SLA), index (LAI), growth duration mostly negatively loss. Plant measured monoculture had no explanatory value ability tested lines, indicating that weeds is preferable. stable sites, years, seasons; others, they strongly influenced by season. The simplified experimental layout can be screen established moderate (e.g., space, seed, labour). Including such process would enable more identified likely contribute increased resource-use efficiency, reduced losses, lower costs, less reliance herbicides rice-based systems.