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Search Results: 1 - 10 of 4779 matches for " rice pest "
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Plantas infestantes hospedeiras de Rhopalosiphum rufiabdominalis (Sasaki) (Hemiptera: Aphididae) em áreas de cultivo de arroz irrigado
Maziero, Heleno;Guedes, Jerson V.C.;Kruse, Nelson D.;Farias, Juliano R.;
Neotropical Entomology , 2007, DOI: 10.1590/S1519-566X2007000300017
Abstract: rhopalosiphum rufiabdominalis (sasaki) is an insect of world-wide distribution that damages irrigated rice. from september, 2004 to february, 2005, nymphs and adults of this aphid were collected in several host weeds of rice farms in alegrete, quaraí and uruguaiana, located in western of state of rio grande do sul, and restinga seca, in central region of this state, brazil. the insect was found in the root of andropogon bicornis (west indian foxtail), echinochloa colona (jungle rice), oryza sativa (volunteer rice and red-rice), paspalum sp. (paspalum) and soliva pterosperma (lawn burweed).
Isolation and Characterization of Microsatellite Loci in the Asian Rice Gall Midge (Orseolia oryzae) (Diptera: Cecidomyiidae)
Jagadish S. Bentur,Deepak Kumar Sinha,Ch. Padmavathy,Charagonda Revathy,Mayandi Muthulakshmi,Javaregowda Nagaraju
International Journal of Molecular Sciences , 2011, DOI: 10.3390/ijms12010755
Abstract: Microsatellite loci were isolated from the genomic DNA of the Asian rice gall midge, Orseolia oryzae (Wood-Mason) using a hybridization capture approach. A total of 90 non-redundant primer pairs, representing unique loci, were designed. These simple sequence repeat (SSR) markers represented di (72%), tri (15.3%), and complex repeats?(12.7%). Three biotypes of gall midge (20 individuals for each biotype) were screened using these SSRs. The results revealed that 15 loci were hyper variable and showed polymorphism among different biotypes of this pest. The number of alleles ranged from two to 11 and expected heterozygosity was above 0.5. Inheritance studies with three markers (observed to be polymorphic between sexes) revealed sex linked inheritance of two SSRs (Oosat55 and Oosat59) and autosomal inheritance of one marker (Oosat43). These markers will prove to be a useful tool to devise strategies for integrated pest management and in the study of biotype evolution in this important rice pest.
Seletividade de agrotóxicos utilizados na cultura do arroz irrigado ao fungo Metarhizium anisopliae, agente de controle microbiano de Tibraca limbativentris
Rampelotti-Ferreira, Fátima Teresinha;Ferreira, Anderson;Prando, Honório Francisco;Tcacenco, Fernando Adami;Grützmacher, Anderson Dionei;Martins, José Francisco da Silva;
Ciência Rural , 2010, DOI: 10.1590/S0103-84782010005000062
Abstract: searching for integrated control strategies for the insect-pest tibraca limbativentris, the in vitro compatibility between isolated cg 891 of metarhizium anisopliae and several pesticides used in the culture of irrigated rice was evaluated. the followings parameters were studied: vegetative growth, sporulation and the germination viability in pre- and post-contact of the fungus for two concentrations of fipronil, thiametoxan, fenitrothion, carbofuran, pyrazosulfuron-ethyl, bentazon, clomazone, glyfosate and quinclorac and one concentration of tricyclazole and azoxystrobin. significant reductions in the vegetative growth and sporulation of m. anisopliae were observed for fenitrothion, carbofuran and azoxystrobin. the germination in pre-contact was affected by azoxystrobin. the percentage of germination changed the classification of pesticides in relation to its selectivity on the fungus. however, the results show that in vitro, the pesticides fenitrothion, carbofuran, glyfosate and azoxystrobin are harmful to isolated cg 891 of m. anisopliae.
Respuesta de 18 Líneas de arroz (Oryza sativa L.) ante la piriculariosis en la época poco lluviosa
Echevarría,Anayza; Cruz,A; Rivero,Deyanira; Pérez,Noraida; Fabré,Leonila; Cárdenas,Regla M;
Cultivos Tropicales , 2010,
Abstract: blast (pyricularia grisea sacc.) occurrence was evaluated by taking into account the affected leaf area (afa) and infection percentages on rice plant panicle neck during seedling and paniculation stages. thus, 18 rice lines were sown in p. grisea-infected beds using a randomized complete experimental design with three replications and six parental varieties of those lines as control. data were processed and analyzed through comparing correlations and tukey’s multiple range test. results showed that all rice lines were susceptible to blast during seedling stage whereas the opposite happened to panicle neck, since 10 lines (1, 4, 7, 8, 9, 10, 12, 13, 14, and 15) were tolerant. there was not any significant correlation between leaf infection and disease occurrence on panicle neck
Uma importante revis?o sobre o impacto de agroquímicos da cultura de arroz em peixes
Copatti, Carlos Eduardo;Garcia, Luciano de Oliveira;Baldisserotto, Bernardo;
Biota Neotropica , 2009, DOI: 10.1590/S1676-06032009000400023
Abstract: in the rice field, the use of agrochemicals to control rice weeds and pests is recommended to improve yield. however, their use may affect non-target organisms, as the fishes. therefore, this review has like objective to analyze data regarding the effects of agrochemicals used in the rice field in fishes to propose strategies to minimize their impact. there is a large variation in the agrochemicals toxicity, and the determination of the medium lethal concentration in 96 hours is only an initial approach for additional studies, because many of them can provoke changes in biochemical parameters in fish tissues at lower concentrations. these biochemical parameters are more appropriate as biomarkers for agrochemicals. it is suggested to use the minimum recommended dose to minimize the impact of the agrochemicals, as well as to keep the water layer of the rice field for at least two weeks after the application to decompose the active principle and reduce toxicity. besides, the integrated pest management is recommended, even as the rice-fish culture, which avoids the use of agrochemicals and in some situations, may give similar yields.
Monitoreo de Tagosodes Orizicolus M. e incidencia del virus de la hoja blanca "VHB" en el cultivo de arroz en calabozo, estado guárico, Venezuela
Vivas C,Luis E; Astudillo,Dilcia; Poleo,Judith;
Agronomía Tropical , 2009,
Abstract: the incidence of white leaf virus (wlv) and insect population density of sogata, tagosodes orizicolus (muir) 1926, was studied in 10 commercial plots of rice located in the rio guárico irrigation system (rg.i.s). the area under the study was divided into three (3) sections during the dry season from 2003 to 2007. the incidence of wlv also was registered in three commercial plots of rice, both in the dry and rainy season. the objective of this study was the evaluation of wlv effect on rice plants as well as the effect of sogata population density as a vector of the disease in commercial plantings (r.g.i.s). the percentage of plants affected by the virus was very low, ranging between 0.56% and 1.08%, and the insect population density of sogata averaged 3.90 individuals per insect net (double pass)
Profundidade da amostragem de solo e de raízes e índice de infesta??o de Oryzophagus oryzae (Costa Lima, 1936) (Coleoptera: Curculionidae) em cultivares de arroz
Neves, Márcio Bartz das;Martins, José Francisco da Silva;Grützmacher, Anderson Dionei;Lima, Crislaine Alves Barcellos de;Büttow, Germano Tessmer;
Ciência Rural , 2011, DOI: 10.1590/S0103-84782011001200001
Abstract: oryzophagus oryzae is the key insect pest in flooded rice fields in southern brazil. their larvae, known as rice water weevil cause significant yield losses when they cut the roots of rice plants. for the monitoring and survey of the larval population of o. oryzae, on rice fields and rice trials, respectively, are currently used standard samples of soil and roots, with 8.5cm deep and 10cm wide, blown away by submersion and shaking in a sieve with water for the counting of larvae. the visualization of larvae, especially the 1st and 2nd instars, becomes difficult in the suspension formed by the soil samples with these dimensions and the water inside the sieves. thus, an experiment was conducted in a typic albaqualf soil according to the latin square design to determine a sampling depth of soil and roots that makes possible the capture and display a larger number of larvae in a smallest possible volume of soil, in different rice cultivars. the treatments consisted of six rice cultivars ('brs atalanta'; 'brs firmeza'; 'brs ligeirinho'; 'brs querência'; 'brs sinuelo cl'; 'irga 417') and three depths (3, 6 and 9cm) for removing samples of soil and roots, every 10cm diameter. in the immediate withdrawal of samples, it was announced the number of larvae. subsequently, in periodic evaluations, it was announced the number of adults emerged from samples kept intact in plastic buckets with water depth of 13, 16 and 19cm, covered by screened mesh fabric. it was detected a significant interaction between sampling depths and the rice cultivars 'brs sinuelo cl' and 'brs querência' in the rate of infestation of larvae and adults of o. oryzae, respectively. in the case of both variables the number of insects per sample was significantly higher at 6 cm depth than at 3cm, an intermediate in 9cm. it was concluded that in typic albaqualf soil, samples (soil and rice roots) taken from a depth of 6cm are more effective to capture and visualize larvae of o. oryzae in suspension (soil and wa
A Logistic Regression Analysis: Agro-Technical Factors Impressible from Fish Farming in Rice Fields, North of Iran
Seyyed Ali Noorhosseini-Niyaki,Mohammad Sadegh Allahyari
International Journal of Agricultural Management and Development , 2012,
Abstract: This study was carried out to identify Technical-AgronomicFactors Impressible from Fish Farming in Rice Fields.This investigation carried out by descriptive survey duringJuly-August 2009. Studied cities including Talesh, Rezvanshahrand Masal set in Tavalesh region near to Caspian Sea, Northof Iran. The questionnaire validity and reliability were determinedto enhance the dependability of the results. Data were collectedfrom 184 respondents (61 adopters and 123 non-adopters)randomly sampled from selected villages and analyzed usinglogistic regression analysis. Results showed that there was asignificant positive relationship (p<0.05) between biologicalcontrol of pests in rice fields and the fish farming in ricefields. Also, there was a significant negative relationship(p<0.10) between the fish farming in rice fields and variablesof quantity using pesticide of Diazinon in rice fields andnumber of plows in rice fields.
Insight to the Mode of Action of Allium sativum Leaf Agglutinin (ASAL) Expressing in T3 Rice Lines on Brown Planthopper  [PDF]
Arpita Bala, Amit Roy, Niranjana Behura, Daniel Hess, Sampa Das
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.42A052

Brown planthopper, the sap sucking hemipteran pest, is one of the major contributors to the yield loss of rice through the world. To combat the situation researchers are interested identifying genes from plant origin having potentiality to develop hemipteran pest resistance. Interestingly, it was observed that rice plants expressing ASAL, a monocot mannose binding lectin, showed significant resistance to brown planthopper and green leafhopper. Additionally, antibiotic resistant marker gene free ASAL expressing rice lines were developed to overcome the biosafety issues. However, the basis behind the resistance against planthoppers is still not clearly understood. Ligand blot assay was performed with total BBMV protein from BPH and a ~56 kDa receptor protein was detected. LC MS/MS analysis revealed that the receptor protein is NADH quinone oxidoreductase (NQO), a key player in electron transport chain, insect defense response and male/female gametogenesis. Presumably interaction of ASAL with NQO may lead to toxicity and loss of fecundity among BPH feeding on ASAL expressing transgenic rice plants. These findings provide a stable scientific basis for considering these transgenic ASAL expressing rice plants as significant product for combating BPH attack associated yield loss of rice.

Sustainable rice pest management and its economic benefits

LIU Guangjie,Kazushige SOGAWA,CHEN Shigao,PU Zhengguo,SHEN Junhui,SHI Dungui,QIAO Qingchun,LIU Xianggui,

应用生态学报 , 2006,
Abstract: With rice varieties Jiahua 1 (resistant to the white backed plant hopper Sogatella furcifera) and Shanyou 63 (susceptible) as test materials, this paper studied the effects of different insecticide treatments on the pest population and quality and yield of rice grain, and evaluated their actual economic benefits (AEB). The results indicated that in the control plot, the peak density of S. furcifera on Jiahua 1 was only 1/10 of that on Shanyou 63. Throughout the whole rice growth period, the S. furcifera population on Jiahua 1 kept below economic injury level, while Shanyou 63 suffered heavy infestation by S. furcifera. The spider density in the control plot was 3 -7 times higher than that in the plots treated with insecticide following farmers' practice. No application of insecticide decreased the grain yield of Jiahua 1 and Shanyou 63 by 11. 8% and 43.4% , respectively. Compared with the control, spraying with insecticide one time decreased the AEB of Jiahua 1 and Shanyou 63 by 0.9% - 2.6% and 2.6% - 4.7% , respectively. Without insecticide application, the AEB of Shanyou 63 decreased by 32.9% - 36.1% , while that of Jiahua 1 increased by 2.2% - 4.8%. The income of planting Jiahua 1 without insecticide application was 9403 yuan x hm(-2) , which was remarkably higher than that (8632 yuan hm (-2)) of Shanyou 63 protected by spraying insecticide 3 times. It was worthwhile to point out that insecticide treatment did not affect the processing of rice grain and its commercial and edible quality, but decreased its protein content of Jiahua 1 and Shanyou 63.
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