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Home > Integrated Control of Yellow Rice Stem Borer Scirpophaga Incertulas Walker Lepidoptera: Pyralidae

Integrated Control of Yellow Rice Stem Borer Scirpophaga Incertulas Walker Lepidoptera: Pyralidae

Thesis Info

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External Link

Author

Dhuyo, Abdul Rehman

Program

PhD

Institute

University of Sindh

City

Jamshoro

Province

Sindh

Country

Pakistan

Thesis Completing Year

2009

Thesis Completion Status

Completed

Subject

Zoology

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1937

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726475749

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Rice is grown on over 145 million hectares in more than 110 countries in the world. It is staple diet of over half of the world’s population and occupies almost one-fifth of the total world crop land under cereals. Rice crop is also staple food of 2.7 billion peoples in developing countries. Almost 90% of the rice is grown and consumed in Asia. Rice plays an important role in the economy of Pakistan. It is major foreign exchange earner and about 18% of the total foreign exchange is shared by rice. It comes next to wheat as the staple diet and second cash crop next to cotton in Pakistan. Rice is exported around 3.1 million tones earning 1125.82 million US Dollars. The rice crop is subjected to attack by more than hundred species of insect pests in the world. More than seventy species of insect pests have been reported to attack rice crop in Pakistan, of which twenty four species of pests have been commonly observed in Sindh. Among the pests, stem borers are major insect pest of rice crop and responsible for economic crop losses. Twenty one species of stem borers are known to attack rice in the world, of which nine different species have been reported in Pakistan. Among the stem borers, the yellow rice stem borer Scirpophaga incertulas (Walker) is one of the most important to cause colossal losses to rice crop. Globally, S. incertulas alone causes yield losses of 10 million tones. In VIPakistan, more than 90 percent damage was recorded by S. incertulas on rice crop in Pakistan. It is a monophagous insect pest. It attacks rice crop from the seedling stage to harvesting stage and thus can cause complete loss to affected tillers. In Pakistan, insecticides are the main tool to control stem borers. Use of insecticides cause environmental hazards besides various others. Keeping in view the pesticide induced problems; present study was designed to integrate various tactics to control rice stem borers. The efficiency of Neem, Clap-trips and Colocynth Tobacco extracts and chemical insecticide Karate 2.5 EC was investigated against yellow rice stem borer, S. incertulas to restrict pest population. Plant extracts significantly suppressed the population of S. incertulas. The average white heads percentage was noted from 30.63 to 44.77 and 3.72 to 4.00 per cent less in the year 2006 and 2007, respectively in the treated plots than the untreated plot (control). All the treatment including chemical insecticide Karate (standard check) gave the lowest dead hearts and white heads percentage and more numbers of productive tillers and filled grain panicles than the untreated plot (control). The plant extracts have equally controlled S. incertulas as with chemical insecticides. Extracts of Neem, Clap-trips and Colocynth extract produced higher yield than the Tobacco extract and Karate. Maximum number of the different predators were found in neem extract treated plots. On the VIIbasis of tiller infestation, high yield and the number of the predators, neem extract can be recommended as alternative insecticide against insect pest of rice crop. Genetic variability of rice varieties to stem borer attack was significantly observed. Scented rice entries: Lateefy, DR-65, Basmati 385, Basmati 370, Shaheen Basmati, DR-66, DR-61, DR-67, IR67017-13-3-3, PARC-228, Ambreen were noted more susceptible than the coarse rice entries for yellow rice stem borer. The aromatic rice entry Lateefy was recorded moderately resistance to S. incertulas under field and green house conditions than the other aromatic entries. The medium maturing coarse rice entries: Tox 3241-21-3, LTPR-4-32-1-1-1, ITR-344, LT9852-5- 2-1-1, CT22048-3, KAJAT-2, IR86949-1, TCX3162-11-1-2-1, IR65077-33-1-3-3, IR68068-99-1-33, DR-58, IR-6 were comparatively more damaged by yellow rice stem borer as compared to the early maturing rice entries: DR-83XDR-92, DR- 83XDR-46, DR-82XS.Kangani, ZHONG-XIANGI, IR72885-1-4-1-4-3-6, JIANG- ZHOU-XIANGNUD, DR-64 and DR-83. Date of rice transplanting also significantly influenced the stem borer attack. The lowest infestation by S. incertulas was recorded to the 10 th July transplanted crop producing highest yield per hectares. The late transplanting of rice crop in (August) helped in increasing population of S. incertulas, consequently reducing the paddy yield. VIIIHarvesting of paddy at certain levels from soil surface also influence the population of hibernating stem borer larvae. As stubbles height increased larval population of S. incertulas increased. Maximum population of the pest was recorded on stubble height 15 cm. Harvesting of the rice crop should be done 15-20 cm above soil surface. Close harvesting and immediate shifting of harvested paddy will decrease larval population of S. incertulas in stubbles. The rice field should not be left fallow or cultivated without ploughing. Mould Board (MB) plough should be used in rice field for severe larval mortality of S. inertulas. The damage by S. incertulas was observed after fifth week of transplanting. So before fifth week of transplanting application of control measures are not beneficial. Two isolates (274 and 373) with concentration ranging from 10 5 to 10 9 spores/ml of the fungus Beauveria bassiana were tested on eggs, larvae and pupae of S. incertulas. The maximum mortality was noted at higher concentrations (spores/ml). The higher concentrations also reduced egg hatching. The isolate No.274 was more pathogenic than the isolate No.373 to control S. incertulas. B. bassiana has a great potential to control the pest. No effect of B. bassiana was recorded on the predators. IXEating response of the predators (Coccinelid beetle, Carabid beetle, Meadow Grass hopper and Damsel fly) increased as density of eggs and larvae of S. incertulas increased. Among the predators, maximum number of the immature stages of S. incertulas were eaten by Coccinelid beetle. Therefore, we can say that Coccinelid beetle Synhamovia octamaculata is a voracious predator of immature stages. The damsel fly ate significantly less number of eggs and larvae of S. inncertulas than did the other predators. If the damage caused by S. incertulas reaches economic threshold level (ETL), besides other control measures introduction, of the predators will be beneficial for the reduction of pest population. The predators are part of biological control: non hazardous way to keep pest populations under ch
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جس دھج سے کوئی مقتل کو گیا۔۔۔

 

جس دھج سے کوئی مقتل کو گیا۔۔۔۔

جس دھج سے کوئی مقتل کو گیا وہ شان سلامت رہتی  ہے

یہ جان تو آنی جانی ہے اس جاں کی تو کوئی بات نہیں

                                                                                                                میرا قائد میرا میر

 

Development Discourse and Womens Empowerment in Sindh

This research paper investigates and introduces the idea of development discourse and women empowerment question in Sindh. Based on the investigation and analysis of the writings by Sindhi intelligentsia in the Sindhi print media and book publications that present the discourse of development, progress, prosperity, and social change in Sindh, in this paper we engage with and call attention to the question of women empowerment. By integrating women empowerment and rights in this paper, we aim to set the research agenda and draw attention to gender and development theory and practice. In a way, this paper takes up and supports the gender-sensitive research approach to development discourse, public policy, and planning in Pakistan. It prioritizes gender and women's empowerment framework in research, teaching, and development practice.

Rheological & Release Characteristics of Drugs of Different Solubilities from Semisolid Matrix Filled in Hard Gelatin Capsule

The re-introduced liquid/semisolid matrix technology, in recent past encompasses filling of hard gelatin capsules for thixotropic system at ambient and thermosoftened system at elevated temperature. Formulations in both of the above systems may contain dissolved or dispersed drugs. In the present work thixotropic gels were prepared using a series of hydrophilic poloxamers (Pluronic/Synperonic L31, L43, L62, L64, L92) of different viscosities and composition of polyoxyethhylene and polyoxypropylenein co-polymers thickened with hydrophilic silicon dioxide (Aerosil®A200) to form gel structure. Model drugs of varying solubilities, isoniazid, metronidazole, paracetamol and mefenamic acid were dispersed in gels of above poloxamers. The gel formulations were filled into hard gelatin capsules via syringe. The rheological characteristics, dispersion stability, and FTIR of the gels with and without drugs were investigated. The gels with drugs were additionally characterized for their release pattern. In preliminary studies, twenty separate gels of poloxamers L31, L64 were thickened with concentrations 1 to 10% w/w of Aerosil® A200 to incorporate isoniazid (unsifted, 10% w/w). Different concentration of Aerosil® A200 affected dispersion stability as well as release of the drug incorporated into gels. All gels were thixotropic and shear thinning. A little change in apparent viscosity on storage upto 30 days was noted. Disperse phase sedimentation was not observed with more viscous poloxamer and with higher concentration of silicon dioxide. Higher concentration of Aerosil® A200 resulted into stronger gel structure between silicon dioxide and poloxamers and thereby, hindered release of drug from a gel. Rheograms of poloxamers, L31 and L64 confirmed their Newtonian behaviour, in contrast to the thixotropic behaviour of all gels made with Aerosil® A200 concentrations (1-10% w/w) and 10% w/w isoniazid. Therefore, ii in-vitro release of highly water soluble drug, isoniazid could be controlled by poloxamer/A200 thixotropic gel system which depended upon concentration of Aerosil® A200, viscosity of poloxamer and the aqueous solubility of drug. In the further work, the effect of selected concentration of Aerosil® A200 (8% w/w) and five liquid poloxamers of different viscosities on release of drugs with characterized particle size (180-250 μm) and of different from semi solid matrix/ thixotropic gel filled into hard gelatin capsules was tested by in-vitro dissolution test. The drugs with different solublities used in this study were isoniazid, metronidazole, paracetamol and mefenamic acid. The interaction of drug in gel formulations was also determined by Fourier transform infrared (FTIR) spectroscopy. The release of drugs from different formulations was related to their aqueous solubility, viscosity of poloxamers, and poloxamer’s polyoxyethylene and polyoxypropylene proportions. In most of the formulations drug remains dispersed over a period of one month depending upon the viscosity of gels. Most of the gels showed little change in apparent viscosity on storage. The apparent viscosity for each gel was found to be dependent on the viscosity of poloxamers from which the gel was prepared. Like in preliminary work, rheograms of five pure poloxamers showed Newtonian behaviour whereas each gel exhibited thixotropic and shear thinning. In-vitro dissolution data of drugs from their respective stable gels followed first order kinetics. No chemical interaction or incompatibilities between drugs and polymers were noted by FTIR. Long term stability studies at International conference on harmonization (ICH) recommended conditions of temperature/relative humidity (30°C/65% RH) over one year revealed that almost all the gels retained their rheological, dispersion stability, release profile and chemical integrity. Thus, the hydrophilic semisolid matrix (gels) made by mixing poloxamer and Aerosil® (A200) was suitable for filling into hard gelatin capsules because of their rheological characteristics. The release of drugs with different solubilities could be modified by using iii poloxamers of different viscosity. Overall present research study demonstrates the effect of silicon dioxide on the microstructure of the gel prepared with various poloxamers which is evident from the rheological studies, FTIR and release pattern of the drugs.