Nutrition management is the most important for high yield production but it may affect the response of rice plants to pest and diseases due to the change of microclimate under rice plant canopy. The knowledge of nutri...Nutrition management is the most important for high yield production but it may affect the response of rice plants to pest and diseases due to the change of microclimate under rice plant canopy. The knowledge of nutrition management and its relation with pest and diseases are basis for setting up a high yield production system. Most of the pest and disease control procedures used by farmers can be considered as soil fertility management and these nutrition practices can have impact on the physiological susceptibility of crop plants to pest and diseases by affecting the plant resistance. Silicon content of plants is particularly effective against pest and diseases in rice and certain rice genotypes are more efficient accumulators of silicon, thus making them more resistant. In the absence of natural heritable resistance in rice varieties, resistance could be induced by altemate strategies to suppress certain pest and pathogens. Hence experiments were carried out in two stages during kharif 2010 and 2011 to assess the concentration of silicon in the index leaves of rice plant utilizing 133 varieties in four locations. The silica content of promising varieties ranged from 1.50% to 3.20%, 1.60% to 3.15%, 1.49% to 3.20% and 1.55% to 3.06% with a mean values of 2.50%, 2.48%, 2.51% and 2.43% at Jagtial, Warangal, Rajendranagar and Rudrur centres of Telangana region and not much variation in mean silica content in index leaves at different places. The overall yield from four locations ranged from 2,653 kg/ha to 6,860 kg/ha with a mean of 5,624 kg/ha. The yields recorded at Jagtial, Warangal, Rajendranagar and Rudrur centres ranged from 2,886 to 7,198, 2,653 to 6,831, 2,653 to 6,860 and 4,399 to 5,950 kg/ha, respectively. The lowest mean yield 5,069 kg/ha was noticed at Rudrur and the highest yield 5,940 kg/ha was found at Warangal. The variations in yields might be due to genotypic variations and also due to variations in climatic conditions of different locations.展开更多
This paper describes how aquatic insect diversity in major natural habitats of Agusan marsh relates with nearby ricefields to determine the interdependence between them for sustainable rice production through natural ...This paper describes how aquatic insect diversity in major natural habitats of Agusan marsh relates with nearby ricefields to determine the interdependence between them for sustainable rice production through natural pest control and for conservation of aquatic fauna in the marsh. Sampling for one year including two cropping seasons of rice production was conducted in various natural habitats of the marsh and in the adjoining rice fields. Both the natural habitats and rice fields were characterized in relation to determining habitat suitability for aquatic insects. The sedge-dominated swamp had the highest diversity among the natural habitats, while the fern-dominated swamp had the lowest. In the adjacent ricefields, diversity was similarly highest in the site near the sedge-dominated swamp, while the lowest was in the ricefields adjoining the Sago forest. Species composition of aquatic insects among the habitats differed between the wet and dry seasons. However, similarity patterns exist between natural habitats and rice fields. The closer similarity in species composition between natural habitats and ricefields indicates habitat connectivity which is an important consideration in planning and effective pest management and ecologically sound rice farming in the marsh.展开更多
Sustaining rice （Oryza sativa L.） productivity at high level is a great challenge, particularly in areas where rice productivity declines in spite of following recommended nutrient management practices. Nutrient man...Sustaining rice （Oryza sativa L.） productivity at high level is a great challenge, particularly in areas where rice productivity declines in spite of following recommended nutrient management practices. Nutrient management by integrating organic manures, inorganic fertilizers and biofertilizers may play an important role in improving and sustaining rice productivity. In this study, the authors tried to evaluate the suitable proportion of organic manures and inorganic fertilizers along with biofertilizer to maximize growth and productivity of hybrid rice on sandy-loam lateritic soils of West Bengal, India. The crop having 50% recommended dose of fertilizer （RDF） ＋ 50% recommended dose of nitrogen （RDN） through mustard oil cake （MOC） and 75% RDF ＋ 25% RDN through MOC ＋ biofertilizer significantly increased plant height, number of tillers/m2, leaf area index （LAI）, dry matter accumulation （DMA） and crop growth rate （CGR） at initial and vital period of grain growth over those of 25% RDF ＋ 75% RDN through MOC and 100% RDN through MOC. The former two treatments also increased number of panicles/m2 and number of grains/panicle over those of only organic manuring （100% RDN） or only chemical fertilization （100% RDF） or 25% RDF ＋ 75% RDN through MOC. Crop with 75% RDF ＋ 25% RDN through MOC ＋ biofertilizer or 50% RDF ＋ 50% RDN through MOC produced 20.2%-33.8% higher grain yield and 11.0%-33.3% greater straw yield, and paid higher gross and net returns over other treatments. This study suggests growing hybrid rice with 75% RDF ＋ 25% RDN through MOC ＋ biofertilizer or 50% RDF ＋ 50% RDN through MOC for better growth, higher productivity and greater profit.展开更多
文摘Nutrition management is the most important for high yield production but it may affect the response of rice plants to pest and diseases due to the change of microclimate under rice plant canopy. The knowledge of nutrition management and its relation with pest and diseases are basis for setting up a high yield production system. Most of the pest and disease control procedures used by farmers can be considered as soil fertility management and these nutrition practices can have impact on the physiological susceptibility of crop plants to pest and diseases by affecting the plant resistance. Silicon content of plants is particularly effective against pest and diseases in rice and certain rice genotypes are more efficient accumulators of silicon, thus making them more resistant. In the absence of natural heritable resistance in rice varieties, resistance could be induced by altemate strategies to suppress certain pest and pathogens. Hence experiments were carried out in two stages during kharif 2010 and 2011 to assess the concentration of silicon in the index leaves of rice plant utilizing 133 varieties in four locations. The silica content of promising varieties ranged from 1.50% to 3.20%, 1.60% to 3.15%, 1.49% to 3.20% and 1.55% to 3.06% with a mean values of 2.50%, 2.48%, 2.51% and 2.43% at Jagtial, Warangal, Rajendranagar and Rudrur centres of Telangana region and not much variation in mean silica content in index leaves at different places. The overall yield from four locations ranged from 2,653 kg/ha to 6,860 kg/ha with a mean of 5,624 kg/ha. The yields recorded at Jagtial, Warangal, Rajendranagar and Rudrur centres ranged from 2,886 to 7,198, 2,653 to 6,831, 2,653 to 6,860 and 4,399 to 5,950 kg/ha, respectively. The lowest mean yield 5,069 kg/ha was noticed at Rudrur and the highest yield 5,940 kg/ha was found at Warangal. The variations in yields might be due to genotypic variations and also due to variations in climatic conditions of different locations.
文摘This paper describes how aquatic insect diversity in major natural habitats of Agusan marsh relates with nearby ricefields to determine the interdependence between them for sustainable rice production through natural pest control and for conservation of aquatic fauna in the marsh. Sampling for one year including two cropping seasons of rice production was conducted in various natural habitats of the marsh and in the adjoining rice fields. Both the natural habitats and rice fields were characterized in relation to determining habitat suitability for aquatic insects. The sedge-dominated swamp had the highest diversity among the natural habitats, while the fern-dominated swamp had the lowest. In the adjacent ricefields, diversity was similarly highest in the site near the sedge-dominated swamp, while the lowest was in the ricefields adjoining the Sago forest. Species composition of aquatic insects among the habitats differed between the wet and dry seasons. However, similarity patterns exist between natural habitats and rice fields. The closer similarity in species composition between natural habitats and ricefields indicates habitat connectivity which is an important consideration in planning and effective pest management and ecologically sound rice farming in the marsh.
文摘Sustaining rice （Oryza sativa L.） productivity at high level is a great challenge, particularly in areas where rice productivity declines in spite of following recommended nutrient management practices. Nutrient management by integrating organic manures, inorganic fertilizers and biofertilizers may play an important role in improving and sustaining rice productivity. In this study, the authors tried to evaluate the suitable proportion of organic manures and inorganic fertilizers along with biofertilizer to maximize growth and productivity of hybrid rice on sandy-loam lateritic soils of West Bengal, India. The crop having 50% recommended dose of fertilizer （RDF） ＋ 50% recommended dose of nitrogen （RDN） through mustard oil cake （MOC） and 75% RDF ＋ 25% RDN through MOC ＋ biofertilizer significantly increased plant height, number of tillers/m2, leaf area index （LAI）, dry matter accumulation （DMA） and crop growth rate （CGR） at initial and vital period of grain growth over those of 25% RDF ＋ 75% RDN through MOC and 100% RDN through MOC. The former two treatments also increased number of panicles/m2 and number of grains/panicle over those of only organic manuring （100% RDN） or only chemical fertilization （100% RDF） or 25% RDF ＋ 75% RDN through MOC. Crop with 75% RDF ＋ 25% RDN through MOC ＋ biofertilizer or 50% RDF ＋ 50% RDN through MOC produced 20.2%-33.8% higher grain yield and 11.0%-33.3% greater straw yield, and paid higher gross and net returns over other treatments. This study suggests growing hybrid rice with 75% RDF ＋ 25% RDN through MOC ＋ biofertilizer or 50% RDF ＋ 50% RDN through MOC for better growth, higher productivity and greater profit.
