Reducing iron toxicity in lowland rice through an integrated use of tolerant genotypes and plant nutrient management

摘要

Field experiments were carried out during 1992-1997 under irrigated condition in the lowlands at two sites in Cote d'Ivoire to evaluate the iron toxicity tolerance of promising rice cultivars available in Africa, and to provide additional information for selecting cultivars and breeding materials. Field experiments were also made to study the effects of other nutrients in reducing iron toxicity in tolerant and susceptible rice cultivars. Performance of selected tolerant and susceptible rice cultivars during 1992-1994 at two sites with and without iron toxicity, showed that the apparent loss in yield due to iron toxicity ranged from 4 to 49 percent. Based on the results of five seasons performance, three promising rice cultivars were identified those appear suitable for growing on iron toxic soils, and have potential of producing grain yields in the range of 4 to 5 t ha~(-1). The results also showed that tolerance to iron toxicity and high yields are physiologically compatible. The application ofN, P, K and Zn increased the yields of iron tolerant and susceptible rice cultivars. Overall, the results suggest that iron toxicity in lowland rice can be reduced by exploiting the synergy between genetic tolerance to iron toxicity and nutrient manageme