967 resultados para Rice -- Diseases and pests


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The paper highlights the methodological development of identifying and characterizing rice (Oryza sativa L.) ecosystems and the varietal deployment process through participatory approaches. Farmers have intricate knowledge of their rice ecosystems. Evidence from Begnas (mid-hill) and Kachorwa (plain) sites in Nepal suggests that farmers distinguish ecosystems for rice primarily on the basis of moisture and fertility of soils. Farmers also differentiate the number, relative size and specific characteristics of each ecosystem within a given geographic area. They allocate individual varieties to each ecosystem, based on the principle of ‘best fit’ between ecosystem characteristics and varietal traits, indicating that competition between varieties mainly occurs within the ecosystems. Land use and ecosystems determine rice genetic diversity, with marginal land having fewer options for varieties than more productive areas. Modern varieties are mostly confined to productive land, whereas landraces are adapted to marginal ecosystems. Researchers need to understand the ecosystems and varietal distribution within ecosystems better in order to plan and execute programmes on agrobiodiversity conservation on-farm, diversity deployment, repatriation of landraces and monitoring varietal diversity. Simple and practical ways to elicit information on rice ecosystems and associated varieties through farmers’ group discussion at village level are suggested.

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Since the conclusion of its 14-year civil war in 2003, Liberia has struggled economically. Jobs are in short supply and operational infrastructural services, such as electricity and running water, are virtually nonexistent. The situation has proved especially challenging for the scores of people who fled the country in the 1990s to escape the violence and who have since returned to re-enter their lives. With few economic prospects on hand, many have elected to enter the artisanal diamond mining sector, which has earned notoriety for perpetuating the country's civil war. This article critically reflects on the fate of these Liberians, many of whom, because of a lack of government support, finances, manpower and technological resources, have forged deals with hired labourers to work artisanal diamond fields. Specifically, in exchange for meals containing locally grown rice and a Maggi (soup) cube, hired hands mine diamondiferous territories, splitting the revenues accrued from the sales of recovered stones amongst themselves and the individual ‘claimholder’ who hired them. Although this cycle—referred to here as ‘diamond mining, rice farming and a Maggi cube’—helps to buffer against poverty, few of the parties involved will ever progress beyond a subsistence level

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Transition to diets that are high in saturated fat and sugar has caused a global public health concern as the pattern of food consumption is a mayor modifiable risk factor for chronic non-communicable diseases Although agri food systems are intimately associated with this transition, agriculture and health sectors are largely disconnected in their priorities policy, and analysis with neither side considering the complex inter relation between agri trade patterns of food consumption health, and development We show the importance of connection of these perspectives through estimation of the effect of adopting a healthy diet on population health, agricultural production trade the economy and livelihoods, with a computable general equilibrium approach On the basis of case studies from the UK and Brazil we suggest that benefits of a healthy diet policy will vary substantially between different populations, not only because of population dietary intake but also because of agricultural production trade and other economic factors

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Arsenic contaminated water from tube wells has become the major health problem threatening millions of people in Bangladesh. However, the arsenic (As) contaminated water is not just used for drinking, it is used to irrigate crops, and to wash and prepare food. Contamination of agricultural soils by long-term irrigation with As contaminated water can lead to contamination and phyto-accumulation of the food crops with As and other toxic metals. As a consequence, dietary exposure to As and other toxic metals may contribute substantially to the adverse health effects caused by the contaminated tube wells in Bangladesh. Various vegetables, rice, pulses and the grass pea were sampled in Samta village in the Jessore district of Bangladesh and screened for As, Cd, Cu, Pb and Zn by inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. These local food crops provide the majority of the nutritional intake of the people in this area and are of great importance to their overall health. In general, our data show the potential for some vegetables to accumulate heavy metals with concentrations of Pb greater than Cd. The concentrations of As and Cd were higher in vegetables than in rice and pulses. The concentration of Pb was generally higher in rice than in pulses and vegetables. However, some vegetables such as bottle ground leaf, ghotkol, taro, eddoe and elephant foot had much higher concentrations of Pb. Other leafy and root vegetables contained higher concentrations oJ2n and Cu. Rice grown at Samta had increased Pb and As, but, considering an average daily intake of only 260 g rice per person per day, only the Pb is at concentrations which would be a health hazard/or human consumption.

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Diseases in natural ecosystems are often assumed to be less severe than those observed in domestic cropping systems due to the extensive biodiversity exhibited in wild vegetation communities. In Australia, it is this natural biodiversity that is now under threat from Phytophthora cinnamomi. The soilborne Oomycete causes severe decline of native vegetation communities in south-western Victoria, Australia, disrupting the ecological balance of native forest and heathland communities. While the effect of disease caused by P. cinnamomi on native vegetation communities in Victoria has been extensively investigated, little work has focused on the Anglesea healthlands in south-western Victoria. Nothing is known about the population structure of P. cinnamomi at Anglesea. This project was divided into two main components to investigate fundamental issues affecting the management of P. cinnamomi in the Anglesea heathlands. The first component examined the phenotypic characteristics of P. cinnamomi isolates sampled from the population at Anglesea, and compared these with isolates from other regions in Victoria, and also from Western Australia. The second component of the project investigated the effect of the fungicide phosphonate on the host response following infection by P. cinnamomi. Following soil sampling in the Anglesea heathlands, a collection of P, cinnamomi isolates was established. Morphological and physiological traits of each isolate were examined. All isolates were found to be of the A2 mating type. Variation was demonstrated among isolates in the following characteristics: radial growth rate on various nutrient media, sporangial production, and sporangial dimensions. Oogonial dimensions did not differ significantly between isolates. Morphological and physiological variation was rarely dependant on isolate origin. To examine the genetic diversity among isolates and to determine whether phenotypic variation observed was genetically based, Random Amplified Polymorphic DNA (RAPD) analyses were conducted. No significant variation was observed among isolates based on an analysis of molecular variance (AMQVA). The results are discussed in relation to population biology, and the effect of genetic variation on population structure and population dynamics. X australis, an arborescent monocotyledon indigenous to Australia, is highly susceptible to infection by P. cinnamomi. It forms an important component of the heathland vegetation community, providing habitat for native flora and fauna, A cell suspension culture system was developed to investigate the effect of the fungicide phosphonate on the host-pathogen interaction between X. australis and P. cinnamomi. This allowed the interaction between the host and the pathogen to be examined at a cellular level. Subsequently, histological studies using X. australis seedlings were undertaken to support the cellular study. Observations in the cell culture system correlated well with those in the plant. The anatomical structure of X australis roots was examined to assist in the interpretation of results of histopathological studies. The infection of single cells and roots of X. australis, and the effect of phosphonate on the interaction are described. Phosphonate application prior to inoculation with P. cinnamomi reduced the infection of cells in culture and of cells in planta. In particular, phosphonate was found to stimulate the production of phenolic material in roots of X australis seedlings and in cells in suspension cultures. In phosphonate-treated roots of X australis seedlings, the deposition of electron dense material, possibly lignin or cellulose, was observed following infection with P. cinnamomi. It is proposed that this is a significant consequence of the stimulation of plant defence pathways by the fungicide. Results of the study are discussed in terms of the implications of the findings on management of the Anglesea heathlands in Victoria, taking into account variation in pathogen morphology, pathogenicity and genotype. The mode of action of phosphonate in the plant is discussed in relation to plant physiology and biochemistry.

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This research project was a response to the outbreak of white blister rust disease and its spread to Brassica oleracea crops in Australia. Disease management strategies based on the understanding of the Albugo - Brassica pathosystem, epidemiology, and the use of chemical control measures were developed for the Australian Brassica industry.

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Improved and traditional rice varieties grown in Sri Lanka namely, Bg 300, Bg 352, Bg 358, Bg 406, LD 356, Rathkaral, Wedaheenati and Heendikwel were studied for their in vivo glycemic response. Proximate compositions and amylose content of rice were determined according to standard methods and available carbohydrate content was calculated using the difference method. The in vivo glycemic response of selected improved and traditional rice varieties was assessed by determining the glycemic index (GI) using ten healthy subjects. Further, the effect of parboiling of rice on glycemic response was also assessed. The crude protein content was higher in parboiled rice as compared to nonparboiled rice. According to the amylose content, rice varieties studied were classified as intermediate and high amylose rice. The amylose content of Bg 406 was the lowest (20.18% ±0.17) while Rathkaral showed the highest (29%±0.07). The Glycemic index of rice varieties studied ranged from 57±1 to 73± 2. The Wedaheenati variety exhibited the lowest GI while Bg 406 exhibited the highest GI value. Unparboiled Bg 406, LD 356 and parboiled Bg 406 were classified as high GI foods while the rest of the rice varieties studied were categorized as intermediate GI foods. Parboiled rice brought about a reduction in glycemic response in healthy subjects. The maximum reduction of 10% in glycemic index upon parboiling was observed with Bg 352. The traditional rice produced significantly lower (p<0.05) postprandial glycemic effect than did the improved rice. By their low post-prandial glycemic response they could be potentially useful in low GI diets.

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Provides a systematic analysis of the health system use and costs associated with specific disease and injury groups in Australia in 1993-94. The estimates are presented in a consistent format and are derived using a methodology that ensures the results add across disease, age and sex groups to total Australian health expenditures for 1993-94.

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Transition to diets that are high in saturated fat and sugar has caused a global public health concern as the pattern of food consumption is a mayor modifiable risk factor for chronic non-communicable diseases Although agri food systems are intimately associated with this transition, agriculture and health sectors are largely disconnected in their priorities policy, and analysis with neither side considering the complex inter relation between agri trade patterns of food consumption health, and development We show the importance of connection of these perspectives through estimation of the effect of adopting a healthy diet on population health, agricultural production trade the economy and livelihoods, with a computable general equilibrium approach on the basis of case studies from the UK and Brazil we suggest that benefits of a healthy diet policy will vary substantially between different populations, not only because of population dietary intake but also because of agricultural production trade and other economic factors

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)