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Dissertations / Theses on the topic 'Tobacco Diseases and pests Control'

Author: Grafiati

Published: 4 June 2021

Last updated: 19 February 2022

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1

Parsons, Stephen H. "Comparing orchid transformation using agrobacterium tumefaciens and particle bombardment." Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/941350.

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The Wheeler Orchid Collection is home to some of the most endangered species of orchids in the world. This fantastic reservoir of endangered species has been enhanced and broadened by its function as a plant rescue station for the U.S. customs service. Unfortunately, this responsibility increases the risk of bringing orchids, which harbor contageous diseases, into the greenhouse where sap transmitted diseases such as the Tobacco Mosaic Virus (TMV), can run rampant. Although manipulation of orchid characteristics is typically done by classical plant breeding techniques, genetic engineering is e

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2

Hutchinson, Chad M. "Agrobacterium tumefaciens mediated transformation of orchid tissue with the sense and antisense coat protein genes from the odontoglossum ringspot virus." Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/834608.

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This research was an attempt to use a dicot transformation vector to transform a monocot. The initial purpose of this thesis was to transform orchids with the sense and antisense coat protein genes from the Odontoglossum ringspot virus (ORSV) in an effort to mitigate viral symptoms in transgenic plants using the transformation vector, Agrobacterium tumefaciens. However, it soon became apparent that much time would be needed to develop a transformation protocol. The transformation vectors used included the Agrobacterium tumefaciens disarmed strain LBA4404 with the binary plasmid pB1121, the dis

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3

De, Beer Abre. "Overexpression and evaluation of an antimicrobial peptide from Heuchera sanguinea (Hs-AFP1) for inhibition of fungal pathogens in transgenic tabacco." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52983.

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Thesis (MSc)--University of Stellenbosch, 2002.<br>ENGLISH ABSTRACT: Seed germination is the most vulnerable time in a plant's life cycle, since the thick protective seed coat ruptures and the moist and humid soil environment not only favours seed germination, but also the growth and development of plant pathogens. Infection of plant seeds during germination, however, is the exception rather than the rule. Plant seeds have - - -developed a--cemplex preformed defense mechanism that includes anttfungal agents thatdiffuse into the surrounding environment to form a protective layer around th

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4

Tuncer, Taner. "Transformation Of Tobacco (nicotiana Tabaccum) With Antimicrobial Pflp Gene And Analysis Of Transgenic Plants." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607007/index.pdf.

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The objective of this study was to transform sweet pepper ferredoxin-like protein (PFLP) gene, which has antimicrobial properties, to tobacco and investigate the disease resistance abilities of transgenic tobacco. This protein interacts with another protein, harpin that is produced by the bacteria which is invading the plant tissues, and stimulates hypersensitivity response in plants, thus the spreading of disease is limited. Gene transfer was achieved to tobacco by Agrobacterium- mediated method and with indirect organogenesis<br>the explants were grown on selective media and then transferr

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5

Terry, Alan J. "Control of pests and diseases." Thesis, University of Surrey, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505965.

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6

Reed, T. David. "Quantification of tobacco aphid, Myzus nicotianae Blackman, injury to flue-cured tobacco, Nicotiana tabacum (L.)." Diss., Virginia Tech, 1990. http://hdl.handle.net/10919/38956.

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A two year study was conducted to measure the impact of tobacco aphid, Myzus nicotianae Blackman, colonization and cumulative aphid-days on flue-cured tobacco, Nicotiana tabacum (L.). The objectives of the study included quantifying the response of tobacco production variables, cured leaf quality, and cured leaf chemical analysis to the level of cumulative aphid-days. Aphid populations and tobacco plant responses were recorded on an individual plant basis. A gradient in cumulative aphid-days was obtained through the use of temporally distributed aphid colonizations and selective insecticide us

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7

Ploeg, Antoon Teunis. "Associations between tobacco rattle virus serotypes and vector species of Paratrichodorus and Trichodorus nematodes." Thesis, University of St Andrews, 1992. http://hdl.handle.net/10023/13566.

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Tobacco rattle virus (TRY) and trichodorid vector nematodes were found to be widespread in bulb growing areas in The Netherlands. Indications, obtained from pot bait tests, that associations between serotypes of tobacco rattle virus and Paratrichodorus and Trichodorus vector species occurred were confirmed in bait tests using individual trichodorid nematodes. Whereas different Paratrichodorus vector species each transmitted a serologically distinct TRV-isolate, different Trichodorus vector species transmitted serologically indistinguishable TRV-isolates. It remains to be studied whether a part

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8

Denman, Sandra. "Botryosphaeria diseases of proteaceae." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52721.

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Dissertation (PhD (Agric))--University of Stellenbosch, 2002.<br>ENGLISH ABSTRACT: Fungi belonging to the genus Botryosphaeria are heterotrophic micromycetes that can be pathogens on woody plants. They cause serious, and in some cases devastating losses to crops through leaf necrosis, stem cankers and plant death. The Proteaceae cut-flower industry in South Africa accounts for 70% of the national cut-flower enterprise. Botryosphaeria diseases are a major impediment to production and trade of Proteaceae and there is an urgent need to investigate the etiology, epidemiology and control of t

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9

Wakgari, Waktola (Waktola Muleta). "Biology, ecology and management of white wax scale, Ceroplastes destructor Newstead (Hemiptera: Coccidae), on citrus and syzygium." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51637.

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Thesis (PhD)--University of Stellenbosch, 2000.<br>ENGLISH ABSTRACT: The population density of the white wax scale, Ceroplastes destructor Newstead, has increased since 1994 in certain areas of Western and parts of Eastern Cape Provinces of South Africa where citrus is grown, particularly on Citrus reticulata (Blanco). A study was conducted to investigate its morphology, biology and ecology as contributions to the development of a sound integrated management programme. Characteristics of the immature stages and adult females were described and illustrated from field-collected and slide-

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10

Specht, Lawrence P. "Inoculum densities of Thielaviopsis basicola in tobacco fields in Virginia, and the relationship of inoculum density to the severity of black root rot and growth of tobacco." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/49854.

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A new selective medium (TB-CEN) was developed for isolating Thielaviopsis basicola, cause of black root rot of tobacco, from soil. TB-CEN medium contains etridiazol and nystatin to inhibit the growth of undesired fungi, and unautoclaved extract from carrot to selectively enhance for the growth of T. basicola. Inoculum and/or population densities of T. basicola in five burley tobacco fields were 74-166 propagules per g of soil, and 0-12 propagules per g of soil in three other burley fields. Inoculum and/or population densities of T. basicola in 12 flue-cured and 2 sun-cured tobacco fields were

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11

Barnes, Martha Letcher. "The relationship of time of year, geographic location, insecticide exposure and the genotype of red and green morphs of the tobacco aphid, myzus nicotianae Blackman, in Virginia." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-06102009-063011/.

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12

Greiner, Blake William. "Inoculation and Spread of Dickeya in Potatoes." Thesis, North Dakota State University, 2019. https://hdl.handle.net/10365/29461.

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Field experiments were conducted in two different growing environments to evaluate the spread and movement of Dickeya dadantii. A procedure to inoculate seed potatoes with Dickeya dadantii was developed to use during this study. Spread of Dickeya dadantii from inoculated potato seed to healthy potato seed during the handling, cutting and planting procedures was not detected at either location. Spread of Dickeya dadantii from inoculated seed to surrounding progeny tubers in the field was documented in both locations. In Florida, 33% of progeny tubers tested positive for Dickeya using PCR, and i

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13

Schuck, Heather A. "Differentially expressed genes of Sophrolaeliacattleya Ginny Champion "Riverbend" in response to the odontoglossum ringspot virus." Virtual Press, 2000. http://liblink.bsu.edu/uhtbin/catkey/1164841.

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Due to the rapid destruction of native orchid habitats it has become necessary to house many endangered orchid species in greenhouse environments where enhanced spread of viral disease occurs due to the close contact between plants. This research was concerned with the construction of a library of genes whose expression is induced in response to viral challenge. In uncovering the genes that are activated during plant-pathogen interactions, it may be possible to manipulate these pathways to develop virus resistant orchids. Furthermore, this research will contribute additional information for th

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14

Windell, Nicole Elizabeth. "Leaf blackening and the control thereof in selected Protea species and cultivars." Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20396.

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Thesis (MScAgric)--Stellenbosch University, 2012.<br>ENGLISH ABSTRACT: Leaf blackening, a postharvest disorder which is characterized by a dark brown to black discoloration, is found in most commercially important Protea cut flower species and cultivars. As this disorder is known to increase with storage time, it is a major concern to the South African industry as the use of sea freight is increasingly preferred due to lower transport costs and a more favourable carbon footprint. The cause of leaf blackening has been strongly linked to a carbohydrate stress exerted by the large infloresce

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15

Groenewald, Michelle. "Characterization and control of Phaeomoniella chlamydospora in grapevines." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51650.

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Thesis (MScAgric)--University of Stellenbosch, 2000.<br>ENGLISH ABSTRACT: Petri grapevme decline, also known as black goo, slow die-back and Phaeoacremonium grapevine decline, causes significant losses of young vines worldwide. Species of Phaeoacremonium, Phaeomoniella chlamydospora and related genera are associated with this grapevine disease. This study investigates the Phaeoacremonium-complex and Phaeomoniella chlamydospora, focussing on the species isolated from grapevines. Fungicide sensitivity of Pa. chlamydospora and the possibility of employing molecular techniques for the detec

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16

Heunis, J. M. (Juanita Maria). "The influence of synthetic pyrethroids on phytophagous mites and their natural enemies in apple orchards." Thesis, Stellenbosch : Stellenbosch University, 1992. http://hdl.handle.net/10019.1/69805.

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Thesis (MSc)--Stellenbosch University, 1992.<br>One copy microfiche.<br>ENGLISH ABSTRACT: The effects of synthetic pyrethroids on the spider mite, Tetranychus urticae Koch, and its natural enemies was investigated. The pyrethroid cyfluthrin, sprayed for the control of fruit weevil Phlyctinus callosus, did not cause mite outbreaks and was not harmful to the predators when sprayed before they appeared on the apple trees. This spray also gave good control of thrips, bollworm (Heliothis armigera) and fruit weevil (P. callosus). A late season spray of deltamethrin against codling moth, cause

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17

Sassi, Giovanna. "Relative quantification of host gene expression and protein accumulation upon turnip mosaic potyvirus infection in tobacco." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81433.

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Turnip mosaic virus (TuMV) infects a variety of crops, worldwide, including the economically relevant Brassicacea family. It was previously demonstrated that TuMV infection in tobacco protoplasts leads to an overall decrease of host protein. However, it remains unclear whether this phenomenon is due to the repression of plant gene transcription during the infection period or due to viral inhibition of host translation. In this study, quantification of various transcripts and protein products from infected tobacco was performed via real-time RT-PCR and ELISA. In comparison to the gamma-t

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18

Odendaal, Deidre. "Orchard and bin treatment with entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) for the control of the codling moth (Cydia pomonella)." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97962.

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Thesis (MSc)--Stellenbosch University, 2015.<br>ENGLISH ABSTRACT: The codling moth, Cydia pomonella (Lepidoptera: Tortricidae), is the key pest of apples and pears worldwide. The withdrawal of certain fundamental chemicals from codling moth management spray programmes, due to concerns about human, environmental and ecosystem health, has resulted in the search for softer, more environmentally friendly, and safer control measures. Entomopathogenic nematodes (EPNs), naturally occur in the soil, and actively search for hosts. The interest in using EPNs from the families Heterorhabditidae and Stein

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19

Ceballo, Flor Angel Aquino. "An investigation into why coccidoxenoides peregrinus (timberlake) (hymenoptera:encyrtidae) is an effective biological control agent in Queensland citrus /." St. Lucia, Qld, 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16498.pdf.

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20

Mostert, Lizel. "The characterization and control of Phomopsis cane and leaf spot on vine." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51945.

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Thesis (MScAgric.)--Stellenbosch University, 2000.<br>ENGLISH ABSTRACT: Phomopsis cane and leaf spot disease of grapevine is an economically important disease in many of the vine-growing areas of the world. Four different Phomopsis spp. have previously been associated with this disease. The present study investigates the taxonomic significance of the different taxa found on grapevines in South Africa, as well as the endophytic growth and fungicide sensitivity of Phomopsis viticola isolates. The thesis is compiled of several different parts, which deal with specific, but related topics, a

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21

Rodas, Pelaez C. A. (Carlos Alberto). "Important pests and diseases of plantation grown Pinus and Eucalyptus in Colombia and their control." Thesis, University of Pretoria, 2013. http://hdl.handle.net/2263/32968.

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Colombia covers an area of approximately 114 million hectares (ha) of which the potential forestly land has been estimated at 60.7 million ha, about 53% of the total area. Only 54 million ha are considered as natural forest, leaving approximately 29 million ha to be used for livestock and agriculture. In order to provide an alternative source of timber, Colombian groups have planted approximately 327 000 ha to different species of Pinus, Eucalyptus and native species. This clearly represents only a small proportion of the total area that might be used for forestry, which is set to grow

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22

Kirkman, Wayne. "Understanding and improving the residual efficacy of the cryptophlebia leucotreta granulovirus (Cryptogran)." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1005482.

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False codling moth (FCM), Thaumatotibia (=Cryptophlebia) leucotreta (Meyr) (Lepidoptera: Tortricidae), is one of the most important pests on citrus. The Cryptophlebia leucotreta granulovirus (CrleGV) has been developed into a successful biological control agent, registered under the name Cryptogran, and is currently the preferred product for the control of FCM on citrus in South Africa. A prerequisite to the continued success of Cryptogran as a means of controlling false codling moth is to understand the factors affecting field persistence of the virus, and to find ways to improve it. The aim

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23

Moore, Sean Douglas. "The development and evaluation of Cryptophlebia Leucotreta granulovirus (CrleGV) as a biological control agent for the management of false codling moth, Cryptophlebia Leucotreta, on citrus." Thesis, Rhodes University, 2003. http://hdl.handle.net/10962/d1004001.

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A granulovirus isolated from Cryptophlebia leucotreta larvae was shown through restriction endonuclease analysis to be a novel strain (CrleGV-SA). No more than one isolate could be identified from a laboratory culture of C. leucotreta. However, a preliminary examination of restricted DNA profiles of isolates from different geographical regions indicated some minor differences. In surface dose bioassays on artificial diet, LC50 and LC90 values with neonate larvae were estimated to be 4.095 x 103 OBs/ml and 1.185 x 105 OBs/ml respectively. LT50 and LT90 values with neonate larvae were estimated

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24

Opoku-Debrah, John Kwadwo. "Geographic variation in the susceptibility of false colding Moth, Thaumatotibia Leucotreta, populations to a granulovirus (CrleGV-SA)." Thesis, Nelson Mandela Metropolitan University, 2008. http://hdl.handle.net/10948/984.

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The false codling moth (FCM), Thaumatotibia (=Cryptophlebia) leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a serious pest of citrus and other crops in Sub-Saharan Africa. The introduction of the Cryptophlebia leucotreta granulovirus (CrleGV-SA) Cryptogran and Cryptex (biopesticides) has proven to be very effective in the control of FCM. However, markedly lower susceptibility of some codling moth (CM), Cydia pomonella (L.) populations to Cydia pomonella granulovirus (CpGV-M), another granulovirus product used in the control of CM’s in Europe have been reported. Genetic differences between

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25

Ferguson, Kaye. "The biology, ecology and management of the Quandong moth, Paraepermenia santaliella (Lepidoptera: Epermeniidae)." Title page, contents and summary only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phf3523.pdf.

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Includes bibliographical references (leaves 217-230). Details the biology and life history of the Quandong moth and investigates management strategies that would enable growers to manage the pest in an economically and environmentally sustainable program.

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26

Prud'homme, Anne-Marie. "Studies on relative fitness of two races of Puccinia helianthi, in mixture, on sunflower." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66173.

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27

Tilly, Gaoh Abdouramane. "Potential of selected natural products as repellents against vertebrate pests of crops." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ50896.pdf.

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28

Neethling, Jacob van der Westhuizen. "Biologiese beheer van plantparasitiese nematodes met die swam Paecilomyces lilacinus by aartappels, sitrus en wingerd." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53311.

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Thesis (MSc)--Stellenbosch University, 2003.<br>ENGLISH ABSTRACT: Paecilomyces Ii/acinus, ras 251 (geregistreer in terme van wet 36 van 1947 as Suid-Afrika se eerste natuurlike nematisiede en kommersieel beskikbaar as PI Plus) is as biologiese beheer agent getoets by aartappels en in geïntegreerde beheer programme by sitrus en wingerd teen respektiewelik Me/oidogyne species, Ty/enchu/us semipenetrans en verskeie ektoparasitiese nematodes. Die swam toon belofte vir die beheer van hierdie nematodes en het terselfdertyd nie 'n nadelige effek op nie-teiken, voordelige organismes in die grond

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29

Birdwhistell, Amie J. "Movement patterns and phenology of the tobacco thrips, Frankliniella fusca (Hinds), in Virginia peanuts." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-06102009-063051/.

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30

Ferreira, Anton. "Further studies on leaf blackening of proteas." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/2879.

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Thesis (MscAgric (Horticulture))--University of Stellenbosch, 2005.<br>The occurrence of both pre- and postharvest leaf blackening in certain Protea species and cultivars is a problem that severely limits their marketability, vase life and transport options. This research focuses on : (I) The distribution of carbohydrates in inflorescence bearing stems of certain Protea cultivars from harvest, following pulsing with a 10 g.L-1 glucose solution until four weeks postharvest. Stems were held under a variety of postharvest conditions, and (II) The suppression of Protea postharvest leaf blackening

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31

Uaciquete, Americo. "Epidemiology and control of powdery mildew (Oidium anacardii Noack) on cashew (Anacardium occidentale L.) in Mozambique." Diss., University of Pretoria, 2003. http://hdl.handle.net/2263/24486.

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For a successful and economical integrated control program aimed at a particular disease, pertinent information, regarding the environmental conditions prevailing in the growing area, the crop itself and the pathogen, must be available. Recently, the control of powdery mildew disease on cashew has moved from the use of non-systemic fungicides with a wide range of action, to highly specific systemic ones. Such a shift requires a more effective integrated control system, whereby tolerant varieties in combination with fungicide unaffected biocontrol agents are timely used to ensure disease contro

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32

Abraham, Varghese. "Evaluation of a forecaster and establishment of action thresholds to begin fungicide applications against cercospora blight of carrot." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69674.

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Forecasts for the first fungicide application to manage cercospora blight of carrot (Daucus carota L. subsp. sativus (Hoffim) Arcang) caused by Cercospora carotae (Passerini) Solheim were evaluated during the summers of 1991 and 1992. In the forecast based on infection, the blight severity values (BSV) were calculated for each day using duration of leaf wetness, relative humidity and temperature. The first fungicide was applied when the cumulative blight severity value reached 14 (CBSV 14) and 18 (CBSV 18). The forecasts were compared with the 50% disease incidence threshold method where the f

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33

Martinez, Granja Edgar. "Factors influencing the development of septoria blight in celery." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=70363.

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Septoria blight of celery (Apium graveolens) caused by Septoria apiicola is a common disease. This work dealt with the development of a simple forecast model to time fungicide application to manage the blight. Two studies were conducted to examine the effect of relative humidity (65, 88, 92, 96%, and wet) temperature (15, 20, 25, and 28 C) and exposure period (6, 12, 24, 48, 72, and 96 hr) on spore production. Spores were produced at all levels of relative humidity and temperature tested. Overall spore production increased with increasing relative humidity. The greatest and the least were prod

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Smith, Risa Barbara. "Plant size, resource concentration and natural enemies : a comparison of four herbivores in monocultures of brussels sprouts and dicultures of brussels sprouts/peppermint." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30791.

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This thesis was designed to address three seldom studied aspects of the relationship between herbivores and vegetational diversity. 1. Interactions between vegetational diversity and herbivore mortality due to predation were assessed by experimentally manipulating both the species diversity of plants and the densities of a common generalist predator, the spider Enoplagnatha ovata. 2. The importance of plant size to herbivore densities was examined by quantifying plant size (measured as plant height, width, leaf area and growth rates) and adjusting for it through covariate analysis. 3. Differen

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Mathewson, Johanna. "Die insekplaagkompleks op sitrus te Vaalharts." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51706.

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Thesis (MSc)--Stellenbosch University, 2000.<br>Full text to be digitised and attached to bibliographic record.<br>ENGLISH ABSTRACT: The cultivation of citrus in the Vaalharts region is a fairly recent development. With the introduction of this crop, an insect pest complex has also developed in this region. The presence of these pests was studied in eleven orchards, planted with three citrus cultivars and of varying ages, distributed in the 300 square kilometer cultivation area. Each orchard was inspected for the presence of pests by making use of two weekly sampling techniques. Ten of

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Rogers, Richard E. L. "Insect and mite monitoring in commercial apple orchards in Nova Scotia (1979-1985)." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65368.

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Borth, Paul William. "Traditional and geostatistical modeling of pink bollworm spatial dynamics in Arizona cotton with application to sampling and computer mapping." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184253.

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The within-field spatial distribution of F₁, F₂, and F₃ pink bollworm (PBW) (Pectinophora gossypiella Saunders) generations were modeled with Taylor's power law (TPL), Iwao's patchiness regression (IPR), and the geostatistical semivariogram. Kriging interpolation was used to grid data for the generation of isarithmic maps. Distributional patterns and movements within a field are displayed in a time series of three maps depicting density across the field. The sampling protocol was replicated in eight commercial cotton fields in south-central Arizona during 1985 and 1986. Permanent sample statio

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38

Carroll, Audra L. "Sense and antisense oligonucleotide inhibition of the Odontoglossum ringspot virus (ORSV) coat protein gene via microprojectile bombardment of orchid callus tissue." Virtual Press, 1999. http://liblink.bsu.edu/uhtbin/catkey/1210536.

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A major goal of our laboratory is to confer resistence specifically to the Odontoglossum ringspot virus [ORSV; sometimes referred to as tobacco mosaic virus strain O (TMV-O)] in orchids. The chosen strategy may also provide cross-protection to other pathogens. The experimental design for the entire project is presented here along with the results obtained in several preliminary experiments performed in this research. Our approach involved RT-PCR amplification of the viral coat protein gene with gene-specific primers and digestion of the cDNAs into oligonucleotides. These fragments were cl

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Brew, Tasha Marie 1961. "INTEGRATED PEST MANAGEMENT PROGRAMS IN COOPERATIVE EXTENSION." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276525.

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The purpose of this study was to assess the adoption response of cotton growers to Integrated Pest Management (IPM) programs, identify the extension strategies used to promote IPM, and provide descriptive comparison of IPM programs between the foremost eleven cotton-producing states in the United States. Integrated pest management is presented as an alternative agricultural production strategy referred to as sustainable agriculture. IPM programs for cotton were evaluated by use of a survey instrument and telephone interviews with the IPM coordinators for the eleven cotton-producing states. The

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Sishuba, Nomahlubi. "Investigation of the larval parasitoids of the false codling moth, Cryptophlebia Leucotreta (Meyrick) (Lepidoptera: Tortricidae), on citrus in South Africa." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1016267.

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The study examined the larval parasitoids of Cryptophlebia leucotreta (Meyrick) on citrus in South Africa and aimed to improve the existing rearing techniques of C. leucotreta with a view to mass rearing of biological control agents. The biological characteristics of Agathis bishopi Nixon (Hymenoptera: Braconidae) were studied, with an emphasis on parasitism rates in the field, host stage preference, developmental rate, life span and offspring sex ratios. Two larval parasitoids, A. bishopi and Apophua leucotretae (Wilkinson) (Hymenoptera: Ichneumonidae), and an egg parasitoid, Trichogrammatoid

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Van, Rooi Cicelia. "Infection by dry, airborne Botrytis cinerea conidia and fungicide efficacy on different parts of grape bunches and vinelets." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52888.

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Thesis (MScAgric)--University of Stellenbosch, 2002.<br>ENGLISH ABSTRACT: The evaluation of fungicide efficacy in commercial vineyards can be influenced by the sporadic occurrence of Botrytis cinerea at various positions on vines, differences in bunch structure during bunch development and the phenomenon that symptom expression in shoots and bunches is governed by the resistance reaction of the various shoot and bunch parts. It has been postulated that, following air and water dispersal, infection by solitary conidia should playa prominent role in the epidemiology of B. cinerea on grapev

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Lovering, Nancy. "Collection and evaluation of bacteria for the biological control of late blight of celery : (Septoria apiicola Speg.)." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23914.

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Late blight, caused by Septoria apiicola Speg., is the most important disease affecting celery in Quebec. Biological control was investigated as an alternative to conventional chemical control of late blight. Two hundred and four bacterial isolates were collected from celery leaves, and muck and mineral soils of celery fields in south-western Quebec. Two experiments were conducted to screen the bacteria for antagonism toward Septoria apiicola: one on agar to test for inhibition of pycnidial formation, and the other on leaf disks to test for inhibition of germination of conidia. From these two

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Gendall, Kierryn Leigh. "Agathis bishopi (Nixon) (Hymenoptera: braconidae) its biology and usefulness as a biological control agent for false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: tortricidae), on citrus bishopi (Nixon) (Hymenoptera: braconidae) its biology and usefulness as a biological control agent for false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: tortricidae), on citrus." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1005317.

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The false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is one of the major pests of citrus in South Africa, the others being mealybug, Mediterranean fruit fly, bollworm and some mites. Due to problems such as the expense of pesticides, insects evolving pesticide resistance (Hogsette 1999), chemical residue on the skin of export fruit and the negative impact of pesticides on the environment, it became necessary to find alternative methods for pest control (Viggiani 2000). Agathis bishopi (Nixon) (Hymenoptera: Braconidae), a larval parasitoid of false codling moth

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Teodorczuk, Lucy. "The effect of methyl jasmonate on defense responses in tobacco cells." Thesis, 2012. http://hdl.handle.net/10210/6468.

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M.Sc.<br>in the current study the effect of the addition of methyl Jasmonate (MeJA), chitosan, a cell wall elicitor prepared from Phytophthora nicotlanae to tobacco cells and the subsequent defense responses elicited in these cells were Investigated. The defense responses investigated can be divided into three categories according to the time scale whereby resistance responses in plant cells are induced: early events which included the analysis of lipid peroxidation, the induction of lipoxygenase (L0)0 enzyme activity as well as the changes in phosphoprotein profiles; intermediate to later res

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Van, Jaarsveld Esme. "Phytophthora nicotianae on tobacco and its control in South Africa." Thesis, 2001. http://hdl.handle.net/2263/29953.

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As the causative agent of black shank, Phytophthora nicotianae is a serious threat to tobacco cultivation in South Africa. Research presented in this dissertation describes pathogenicity studies and control measures for P. nicotianae on tobacco. Special attention is given to the population structure of P. nicotianae in South Africa. The implications of these genetic studies in breeding and selection programs against P. nicotianae were also evaluated. The first chapter of this dissertation represents a literature review on black shank and available control measures for P. nicotianae on tobacco.

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Coventry, Helen. "Induced defense responses in plants by bacterial lipopolysaccharides." Thesis, 2012. http://hdl.handle.net/10210/5911.

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M.Sc.<br>Plant disease can be naturally suppressed by plant growth promoting rhizobacteria and endophytic / endorhizosphere bacteria. Apart from direct antagonism against pathogenic organisms, these plant growth promoting bacteria and endophytes can induce a form of systemic resistance (ISR) in plants. The main bacterial inducing component has been suggested to be the outer membrane lipopolysaccharides (LPS), found in the cell walls of Gramnegative bacteria. Burkholderia cepacia (Pseudomonas cepacia) is a bacterial endophyte that has potential as a biocontrol agent. Although a few studies have

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Du, Toit Christiaan Ludolph Neethling. "'n Ekologiese studie van Tetranychus evansi Baker & Pritchard op tabak met spesiale verwysing na die geintegreerde beheer en ekonomiese belangrikheid daarvan." Thesis, 2014. http://hdl.handle.net/10210/11930.

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Van, der Merwe Louise. "Diallel crosses between sources of Black Shank (Phytophthora parasitica var. nicotianae) resistance." Diss., 2002. http://hdl.handle.net/2263/25779.

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The black shank (Phytophthora parasitica var. nicotianae) fungus is a very destructive tobacco disease which is responsible for great losses to farmers worldwide. This disease is also a problem in South Africa, as the most popular South African air-cured tobacco cultivar, CDL28, is very susceptible to black shank. This diallel study focussed on finding the most suitable black shank resistance source to include in a resistance breeding programme with CDL28. Four cultivars were crossed in all possible combinations and planted as an F1 field and greenhouse trial. The F1's were selfed to obtain a

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Calvert-Evers, Jennifer. "Characterization of dsRNA species in tobacco exhibiting non-geminivirus leaf curl symptoms." Thesis, 1996. http://hdl.handle.net/10539/22062.

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A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science. Johannesburg, 1996.<br>Tobacco in Southern Africa has been found to exhibit three forms of leaf curl (class I, II and III) based on symptomology. Class I tobacco leaf curl is a disorder of unknown etiology, appearing as bent or twisted leaves exhibiting frilly enations (leafy outgrowths) along the midrib and secondary veins of severely stunted tobacco plants.[Abbreviated Abstract. Open document to view full version]<b

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Li, Xiao Hua. "Inoculation of apple protoplast with tobacco mosaic virus (TMV) /." 1988. https://scholarworks.umass.edu/theses/3408.

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