Motivations behind farmers’ pesticide use in Bangladesh rice farming     

Elizabeth J. Z. Robinson  Sumona Rani Das  Tim B. C. Chancellor 《Agriculture and Human Values》2007,24(3):323-332

This paper addresses the motivations behind farmers’ pesticide use in two regions of Bangladesh. The paper considers farmers’ knowledge of arthropods and their perceptions about pests and pest damage, and identifies why many farmers do not use recommended pest management practices. We propose that using the novel approach of classifying farmers according to their motivations and constraints rather than observed pesticide use can improve training approaches and increase farmers’ uptake and retention of more appropriate integrated pest management technologies. Elizabeth J. Z. Robinson divides her time between Tanzania and the UK and is a research associate with the Centre for the Study of African Economies at the University of Oxford in the UK. She is an economist specializing in agriculture, natural resources, and the environment. She has over ten years of experience undertaking applied research in South Asia and sub-Saharan Africa as a fellow and lecturer in the Economics Department at the University of Oxford; at the Natural Resources Institute at the University of Greenwich in the UK; and with the World Bank and Rockefeller Foundation in the US. Sumona Rani Das is an agriculture economist who has been working for eight years with a non-government organization in Bangladesh named PROSHIKA. She is involved with monitoring and evaluation of PROSHIKA’s ongoing activities in agriculture, and is working as a team leader with an agriculture network to promote sustainable agriculture. She has special responsibility for motivation, training, project management, and documentation of different programs. Tim B. C. Chancellor is a crop protection specialist and currently is the leader of the Natural Resources Institute’s Plant, Animal and Human Health Group at the University of Greenwich in the UK. He has 17 years research and consultancy experience in vector ecology and in pest and disease management. Other skills include project management, monitoring and evaluation, and public-private partnerships. He is also Adviser to the UK government’s Department for International Development (DFID) Crop Protection Programme. His commodity experience includes rice, banana, groundnut and vegetables.  相似文献   

Salinity Induced Accumulation of Free Amino Acids in Germinating Rice Seeds Differing in Salt Tolerance   总被引：2，自引：0，他引：2  

R. S. Dubey  Manju  Rani 《Journal of Agronomy and Crop Science》1989,163(4):236-247

Metabolic status of total and individual free amino acids were studied in endosperms and embryoaxes of four rice cultivars differing in salt tolerance, growing under increasing levels of saline stress. At all saline treatment levels and in controls salt tolerant cultivars had higher levels of total free amino acids in germinating seed parts than sensitives. Individual free amino acids which always maintained higher levels in germinating tolerant seeds over sensitives were aspartic acid, arginine, glycine and leucine. Salinity caused accumulation of free amino acids in germinating seed parts in all cultivars. Maximum accumulation was of arginine followed by leucine, alanine, valine, glutamine and proline. Individual amino acids accumulated greatly in tolerant cultivars than sensitives. Increased salinity caused decrease in the levels of aspartic acid, serine, glutamic acid, glycine, lysine and histidine in growing embryoaxes. Results suggest possible relationship between levels of free amino acids arginine, leucine, alanine, valine, glutamine and proline and degree of salt tolerance in rice. These all amino acids should be considered in combination as indices for salt tolerance in rice.  相似文献   

Effects of the pesticides thiotox,dichlorvos and carbofuran on the test fishMystus vittatus     

S. R. Verma  Sarita Rani  S. K. Bansal  R. C. Dalela 《Water, air, and soil pollution》1980,13(2):229-234

A quantitative index of synergism, antagonism and additivity has been measured experimentally in the fishMystus vittatus for three pesticides viz. Thiotox (Endosulfan) (T), Dichlorvos (D) and Carbofuran (C). For a combination of two pesticides, the dose of the one pesticide of a pair was fixed at the no-effect level while the dose of the second pesticide was increased until the entire dose response curve was obtained. To evaluate interactions of three pesticides, the previous pair of pesticides was kept fixed at their combined TL_O level, and the third pesticide was increased and again a dose-response curve was obtained. From the results obtained, it is shown that a particular combination could be synergistic, antagonistic or additive, depending on the relative doses employed. In the present study (T + D)/C combination was most synergistic (toxic) in nature while D/T and C/T were least toxic or antagonistic in their effects. However, T/D, (C + T)/D, C/D and D/C combinations were additive in nature. (D + T)/C, (D + C)/T, (T + C)/D and (C + D)/T combinations were found less synergistic in nature than (T + D)/C.  相似文献   

Stem and leaf rust resistance in wild relatives of wheat with D genome (Aegilops spp.)     

V. K. Vikas  M. Sivasamy  J. Kumar  P. Jayaprakash  Sundeep Kumar  R. Parimalan  Arun Kumar  Kalyani Srinivasan  J. Radhamani  Sherry Rachel Jacob  Mamata Yadav  Jyotisna Rani  I. S. Bisht  D. C. Bhandari  Sunil Archak  M. Dutta  R. K. Tyagi  K. C. Bansal 《Genetic Resources and Crop Evolution》2014,61(4):861-874

Resistance to stem rust and leaf rust in five D genome species of wheat viz., 267 accessions of Aegilops tauschii Coss., 39 of Ae. cylindrica Host, 17 of Ae. ventricosa Tausch, 4 of Ae. crassa Boiss. and 8 of Ae. juvenalis (Thell.) Eig were evaluated at adult plant stage. Two hundred and thirty nine (90 %) accessions of Ae. tauschii, 30 (77 %) of Ae. cylindrica, 16 (94 %) of Ae. ventricosa, 3 (75 %) of Ae. crassa Boiss. and 5 (62.5 %) of Ae. juvenalis were resistant to stem rust pathotypes prevalent in South India at Wellington under field condition. Invariably, all the accessions of the five species were resistant to leaf rust pathotypes. Quantitative measurement of disease using area under the disease progress curve revealed the slow progress of disease in the resistant accessions compared to susceptible check (Agra Local). Since all the five species have D genome, it could be concluded that the genes present in D genome might play a vital role in leaf rust resistance, but in case of stem rust resistance wide range of differential response was noticed. Among the species evaluated, Ae. tauschii was exploited to a larger extent, followed by Ae. ventricosa and Ae. cylindrica for leaf and stem rust resistance because of the homology of D genome with hexaploid bread wheat. While, Ae. crassa and Ae. juvenalis could not be utilized so far, possibly due to partial homology which makes the transfer of traits difficult. So, these species have considerable potential as a source of rust resistance and may enhance the existing gene pool of resistance to stem and leaf rusts.  相似文献   

Growth Hormone Receptors in the Porcine Testis During Prepuberty     

MR N'Diaye  SS Sun  SP Fanua  KJ Loseth  EF Shaw Wilgis  BG Crabo 《Reproduction in domestic animals》2002,37(5):305-309

Supplementation of exogenous growth hormone (GH) during prepuberty advances onset of spermatogenesis in boars, but the mechanism of action is unknown. The present study is an investigation of the presence and characteristics of testicular growth hormone receptors (GHR). A total of 36 boars were castrated, three boars every 10 days, between the ages of 10 and 120 days. Testicular membrane preparations of 10, 20, 30, 50, 70, 100 and 120‐day‐old boars were used to determine ¹²⁵I‐bGH binding and Scatchard analysis. Liver from a 60‐kg barrow was used for comparison. Specific ¹²⁵I‐bGH binding to testicular membrane preparations occurred in all age groups with the exception of 20‐day‐old boars at levels of 30–40% of liver binding. At 30 days of age the unlabelled bGH at 1.1 ng/tube achieved half maximal inhibition (ID₅₀). Results of Scatchard analysis indicated a single class of binding sites. Binding affinity was 2.89 × 10⁹m with a binding capacity of 12 fmole/mg membrane protein. The results from this study suggest that GH may act directly on the cells of the prepubertal boar testis.  相似文献   

Geographical variation of total alkaloid and reserpine content in Rauwolfia serpentina (L.) Benth. ex. Kurz     

Gufran Usmani  Pravin H. Chawhaan  Yogeshwar Mishra  Abha Rani  Asim Kumar Mandal 《Euphytica》2015,202(3):427-434

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Effects of pesticides and their combinations on three serum phosphatases of Mystus vittatus     

S. R. Verma  Sarita Rani  R. C. Dalela 《Water, air, and soil pollution》1984,21(1-4):9-14

The effects of thiotox (T), dichlorvos (D), carbofuran (C) and their three combinations C/T (highly antagonistic), T/D (Additive) and (T+D)/C (highly synergistic) on the activities of acid, alkaline and glucose-6-phosphatases in the serum of Mystus vittatus have been determined after 30 days exposure. The three subacute concentrations selected were 1/5th, 1/10th, and 1/15th fractions of 96 hr LC₅₀ values of these pesticides and combinations. In general, the elevation in three phosphatases was observed except at a few places where inhibition was observed at 1/15th fraction. Elevation in alkaline phosphatase was more than acid and glucose-6-phosphatases.  相似文献   

Distribution of vesicular-arbuscular mycorrhizal fungi in coal,lignite, and calcite mine spoils of India     

V. Ganesan  S. Ragupathy  B. Parthipan  D. B. Rajini Rani  A. Mahadevan 《Biology and Fertility of Soils》1991,12(2):131-136

Summary We assessed vesicular-arbuscular mycorrhizal (VAM) fungi in coal, lignite, and calcite mine spoils. The level of VAM fungal infection and the population of VAM species in plants on the coal-waste sites were similar to those in plants on the calcite mine spoil. The plants on the coal-waste sites and their associated VAM fungi included Tephrosia purpurea (L.) Pers. with Glomus heterosporum and Sclerocystis microcarpus and Euphorbia hirta L. with G. botryoides and G. ambisporum. The recently revegetated lignite mine spoil supported Eragrostis sp. with G. globiferum, while the oldest revegetated lignite mine spoil supported Cocos nucifera L. with Scutellospora aurigloba and G. aggregatum, and Albizia lebbeck (L.) Benth. with Scutellospora dipapillosa and G. tenue. In the calcite mine spoil, roots of Mukia maderaspatana (L.) M. Romer with Sclerocystis sinuosa, G. dimorphicum, G. heterosporum and G. ambisporum and Datura metal L. with G. pustulatum and G. pulvinatum were found. The level of VAM infection and the population of VAM species in the oldest revegetated site (lignite mine spoil) were comparable with those in the coal-waste and calcite mine-spoil sites.  相似文献   

DIE AUFNAHME VON ADSORBIERTEM MONOLINURON IM BODEN DURCH SENFPFLANZEN     

A. SÜSS  B. GRAMPP 《Weed Research》1973,13(3):254-266

Zusammenfassung. Um den Einfluß verschiedener Bodenmischungen auf die Aufnahme von adsorbiertem [¹⁴C]-markíertem Monolinuron zu verfolgen, wurden jeweils 30, 45, 60, 73 und 90 g Monolinuron-behandelter Boden (0,42-0,53 μg Monolinuron/g Boden) mit unbehandeltem auf 100 g aufgefüllt und damit 15.4–67.1 μg adsorbiertes Monolinuron eingesetzt. Die Aufnahme durch Senipflanzen wurde in Neubauerversuchen während 24 Tagen verfolgt. In 3 Anbauperioden wurden 1.17–9.74 μg aufgenommen. Der überwiegende Teil blieb jedoch an den Boden adsorbiert. Bei einer Bilanzerstellung konnten 99% der zu Versuchsbeginn eingesetzten Monolinuronmenge wieder gefunden werden, Durch den Sorptionsprozeß wurde Monolinuron chemisch nicht vcerändert. Ebenso kann das Ausgangsmolekül in der Pflanze nachgewiesen werden. Die nachweisbare Monolinuronmenge in der Pflanzensubstariz wird umso geringer, je weiter die Aufnahmeintensität zurürkgeht. Über eine Isotopen-Austauschreaktion wurde versucht, das pflanzenverfügbare Monolinuron zu messen.
The uptake of adsorbed monolinuron in the soil by mustard plants  相似文献   

Oxygen reservoirs in the early solar nebula inferred from an allende CAI     

ED Young  SS Russell 《Science (New York, N.Y.)》1998,282(5388):452-455

Ultraviolet laser microprobe analyses of a calcium-aluminum-rich inclusion (CAI) from the Allende meteorite suggest that a line with a slope of exactly 1.00 on a plot of delta17O against delta18O represents the primitive oxygen isotope reservoir of the early solar nebula. Most meteorites are enriched in 17O and 18O relative to this line, and their oxygen isotope ratios can be explained by mass fractionation or isotope exchange initiating from the primitive reservoir. These data establish a link between the oxygen isotopic composition of the abundant ordinary chondrites and the primitive 16O-rich component of CAIs.  相似文献