Absorption of heavy metals and contaminants through a rice-based diet may have serious consequences for human health. The present study determined the levels of arsenic (As), cadmium (Cd), lead (Pb) and chromium (Cr) in 71 irrigated and rain-fed rice and assessed dietary (rice) exposure to the heavy metals. The concentration in rice grains were generally higher in the irrigated season which may...

Introduction One of the tragic consequences of rice policies in The Gambia over the past twenty years is how severely they undermined the domestic rice sector. Between 1966-1984, international development assistance had promoted irrigation projects on the country's abundant alluvial swamps. The objective was to create surpluses for national demand by growing the second crop by irrigation. Doubl...

Increasing yield potential of lowland rice remains to be the top priority in rice geneticimprovement programmes, because rice farmers’ primary concern is still grain yield and world rice production has to increase by 1% annually in the next 20 years to meet the demand of the growing population. Improvements in yield potential of irrigated lowland rice were achieved under ample supply of water a...

The transfer of arsenic to rice grains is a human health issue of growing relevance in regions of southern Asia where shallow groundwater used for irrigation of paddy fields is elevated in As. In the present study, As and Fe concentrations in soil water and in the roots of rice plants, primarily the Fe plaque surrounding the roots, were monitored during the 4-month growing season at two sites i...

The objectives of this work were estimate the reaction rates of hydrolysis of carbosulfan to carbofuran and subsequent degradation of this last compound in irrigated rice fields, and the respective half life, in aquatic environment and soil solution, by mean of numerical solution of differential ordinary linear equations system that describes the kinetics of insecticide concentrations. The resu...

BACKGROUND Continuous land cover modification is an important part of spatial epidemiology because it can help identify environmental factors and Culex mosquitoes associated with arbovirus transmission and thus guide control intervention. The aim of this study was to determine whether remotely sensed data could be used to identify rice-related Culex quinquefasciatus breeding habitats in three r...

Experiments were conducted to determine methane emission from a rainfed lowland rice field (water depth about 3–30 cm) and an irrigated shallow rice field (4–6 cm), both planted to the same cultivar, cv. ‘Gayatri,’ as influenced by fertilizer management practices. Methane emission peaked from 100 to 125 days after transplanting followed by a decline in rainfed lowland field plots. Application o...

Japanese encephalitis (JE) is a disease caused by an arbovirus that is spread by marsh birds, amplified by pigs, and mainly transmitted by the bite of infected Culex tritaeniorhynchus mosquitoes. The estimated annual incidence and mortality rates are 30,000--50,000 and 10,000, respectively, and the estimated global burden of JE in 2002 was 709,000 disability-adjusted life years lost. Here, we d...

During the last 90 years, the breeding of rice has delivered cultivars with improved agronomic and economic characteristics. Crossing of different lines and successive artificial selection of progeny based on their phenotypes have changed the chromosomal constitution of the ancestors of modern rice; however, the nature of these changes is unclear. The recent accumulation of data for genome-wide...

Biodiversity relevant to pest management of tropical irrigated rice pests is discussed in terms of variation within rice plants, rice fields, groups of rice fields and rice associated ecosystems. It is concluded that, in the unique cropping conditions and stable water supply of tropical irrigated rice, the manipulation of a relatively few manageable components of diversity can confer stability ...