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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Use of the egg parasitoid, Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) as a biological control agent of the European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae): An approach to integrated pest management in bell pepper

Barlow, Vonny M. 05 May 2006 (has links)
Four to six separate inundative releases of ~30,000 to 50,000 T. ostriniae per 0.02 ha significantly reduced damage by O. nubilalis in bell pepper. Egg parasitization averaged 48.7% in T. ostriniae release plots, which was significantly higher than non-release plots (1.9%). Also, cumulative green pepper fruit damage averaged 8.7% in release plots, which was significantly less than non-release plots (27.3%). Pesticides tested against T. ostriniae were spinosad and methoxyfenozide. Spinosad adversely affected adult T. ostriniae producing 100% mortality at the field rate of 498 mg [AI]/L for both the preimaginal and adult toxicity tests. Use of T. ostriniae can provide effective control of O. nubilalis in pepper compared to conventional and organic spray regimes (Spinosad and methoxyfenozide respectively). Augmentative releases of T. ostriniae integrated with methoxyfenozide with its limited toxicity to both preimaginal and adult stages indicate that it is a superior candidate for control O. nubilalis. To determine the behavioral differences of T. ostriniae and its response to O. nubilalis in green bell peppers, experiments were carried out to classify likely areas of O. nubilalis oviposition within the green pepper plant canopy. A total of 426 O. nubilalis egg masses were found on pepper plants during our study. Over 92% of egg masses were found on the lower surface of the leaf compared with the upper surface indicating a significant ovipositional preference for the undersides of leaves in 2002 ( x2 = 9.68; df = 1; P < 0.05) followed by similar results in 2004 (x2 = 4.34; df = 1; P < 0.05). No significant differences were found in the observed spatial distribution of egg masses among the three vertical strata in either 2002 or 2004 (x2 = 1.75; df = 2; P < 0.05 and x2 = 5.69; df = 2; P < 0.05 respectively). Field release rates of 17.0 foraging T. ostriniae females can achieve 80.0% parasitism of O. nubilalis egg masses distributed throughout the pepper plant canopy found primarily on the undersides of leaves. These data demonstrate that T. ostriniae has potential as a biocontrol agent for O. nubilalis in solanaceous crops. / Ph. D.
42

Protocols for the Assessment of Economic and Environmental Effects of Integrated Pest Management Programs

Beddow, Jason Michael 04 October 2000 (has links)
State Integrated Pest Management (IPM) programs are often called on to demonstrate their impacts. While many studies demonstrate techniques for assessing various economic and environmental effects of IPM, the literature provides little guidance on incorporating the techniques to perform complete assessments of IPM programs. This thesis begins with a discussion of relevant economic and environmental techniques for IPM impact assessment. Next, impact assessment techniques that are widely accepted and analytically feasible are identified. These techniques are incorporated into comprehensive impact assessment frameworks for use by individuals charged with the assessment of state level IPM programs. The study concludes with case studies which show how the assessment protocols were applied to estimate and describe the impacts of the Pennsylvania and Massachusetts sweet corn IPM programs. / Master of Science
43

Assessing the Economic Impacts of Tomato Integrated Pest Management in Mali and Senegal

Nouhoheflin, Theodore 06 August 2010 (has links)
This study assesses the research benefits of IPM technologies and management practices aimed at reducing the virus problem in tomatoes in West Africa. Surveys are conducted with producers, extension agents, scientists, and other experts to obtain information and economic surplus analysis is used to project benefits over time. The determinants of adoption are assessed using a probit model. Results show that adoption of the host-free period reduced the amount of insecticide sprays by 71% and the production cost by $200/ha in Mali. The cost-benefit analysis indicated that the use of virus-tolerant seeds generated profits ranging from $1,188 to $2,116/ha in Mali and from $1,789 to $4,806/ha in Senegal. The likely factors influencing adoption of the technologies in both countries are the frequency of extension visits, farmer's field school training, gender, education, seed cost, tomato area, and experience in tomato losses. The benefits in the closed economy market vary from $3.4 million to $14.8 million for the host-free period, $0.5 million to $3 million for the virus-tolerant seeds, and $4.8 million to $21.6 million for the overall IPM program. In the same order, the benefits under the open economy market range from $3.5 million to $15.4 million, $0.5 million to $3million, and $5 million to $24 million. The distribution pattern indicates that producers gain one-third and consumers two-thirds of the benefits. Our results support policies aiming to increase the adoption rate or the expected change in yield. / Master of Science
44

Analyzing the Impacts of an IPM Vegetable Technology Transfer in Bangladesh

McCarthy, Evan Tyler 09 September 2015 (has links)
This study evaluates the effectiveness and impacts of USAID's IPM IL vegetable technology transfer subproject in Bangladesh. The effectiveness of the technology transfer is evaluated in four ways: IPM adoption rates and determinants of IPM adoption, measuring the impact of IPM adoption on vegetable yields, pest management costs, and the number of pesticide applications used, estimation of the economic impacts of IPM adoption and the technology transfer, and analysis of the relative efficiency of the various technology transfer methods used to transfer the IPM practices to farmers. Adoption determinants were identified using traditional and ordered probit regression analysis. Difference-in-difference models were used to identify the impacts of IPM adoption on yields, pest management costs, and the number of pesticide applications applied. Economic impacts of IPM technology adoption were measured using economic surplus analysis. Finally, to compare the relative efficiency of different technology transfer methods, adoption rates were identified for each transfer method and combined with the training cost per farmer to identify the cost per farmer adopting IPM practices. The results from the adoption analysis suggest the number of years of agricultural experience of the household head, the number of IPM adopters known by the household, and learning agricultural information from media sources and/or farm training events such as field days significantly increase the likelihood of IPM adoption. The impacts of IPM adoption on vegetable yields, pest management costs, and the number of pesticide applications were non-significant for vegetable crops. Analysis of the cost efficiency of the different IPM technology transfer methods suggests that media sources such as television, radio, and newspapers have the lowest cost per farmer. / Master of Science
45

Using Pheromone Lures, Insecticide Netting, and a Novel Food-Grade Repellent to Develop BMSB IPM Strategies

Bush, Hayley Grace 21 August 2018 (has links)
The invasive brown marmorated stink bug (BMSB), Halyomorpha halys (Stål), has resulted in increased use of insecticides on horticultural crops in the Mid-Atlantic US, which has diminished integrated pest management (IPM) programs that worked well otherwise. The research herein explored the use of three new tools in the development of BMSB management strategies. In one study, a BMSB pheromone lure was placed on insecticide-incorporated mesh netting to be used in an attract-and-kill strategy to protect bell peppers. The pheromone and netting deployed within a pepper field resulted in more BMSB feeding on plants within 6.1 m to the attract-and-kill screen than in further peppers or peppers in the weekly insecticide treatment. In another study, the insecticidal netting used as a row cover reduced stink bug damage to peppers, but also caused significant yield losses, possibly due to lack of light and/or pollination. The BMSB pheromone lure was also utilized in a sticky trap-based action threshold for insecticide application decisions. The trap and lure predicted densities of bugs on pepper plants and the use of an action threshold of 5 bugs per trap per week to trigger an insecticide spray reduced insecticide applications by 50% at one location, however population densities were lower at the other two locations and significance was not found among treatments. Lastly, BMSB is a nuisance pest to homeowners so we tested the exclusion efficacy of repellents on overwintering shelters and found an 8-fold reduction in BMSB that entered shelters treated with geranyl cyclopentanone (apritone). The use of BMSB pheromones paired with insecticide netting for attract-and-kill of BMSB, the development of action thresholds using captures in pheromone-baited sticky cards, and the use of apritone as a repellent are all promising IPM strategies worth refining in future studies. / MSLFS / The brown marmorated stink bug (BMSB) has become a serious household nuisance and agricultural pest in the US. BMSB feeds on and damages a large variety of crops including, fruits, vegetables, and field crops. Most growers of high value crops have increased their insecticide usage to battle this bug; thus, more sustainable integrated pest management (IPM) approaches need to be established. One main vegetable crop that BMSB damages is bell peppers. One study tested the efficacy of an attract-and-kill approach involving a BMSB pheromone lure paired with insecticide-impregnated mesh netting. When deployed in pepper fields, it was found that BMSB stayed on plants rather than receiving a lethal dose from the netting. Another study tested the netting as a row cover or as a fence between peppers and found that it did little at preventing damage. Furthermore, pepper yields were significantly lower under the row cover treatment. In another study, a clear sticky panel placed on a stake and paired with a BMSB pheromone lure was used to assist in making management decisions based on relative densities of bugs in plots. This can help determine if insecticide applications are needed. Not only is BMSB a pest of agriculture, but it is also a nuisance pest to homeowners when adults seek winter shelter during their fall dispersal period, sometimes entering homes by the thousands. The tactile repellent, geranyl cyclopentanone (apritone), was found to elicit an 8-fold reduction in the number of overwintering BMSB in overwintering shelters.
46

Kinetisk validering av den inverterade pendelmodellen för transfemoralt amputerade / Kinetic validation of the Inverted Pendulum Model for transfemoral amputees

Hallstedt, Karin, Runesson, Jessika January 2018 (has links)
Bakgrund: Transfemoralt amputerade har nedsatt balans och ökad fallrisk, men väldigt lite forskning är gjord om detta. Inverted pendulum model (IPM) är en balansmodell för icke-amputerade som bygger på ett känt samband mellan Center of Pressure (CoP) och Center of Mass (CoM). Syftet med denna studie är att kinetiskt validera den inverterade pendelmodellen för transfemoralt amputerade. Metod: I studien deltog amputerade (n=5) och en matchande kontrollgrupp (n=5). Man samlade in data genom att deltagarna fick stå stilla på två stycken kraftplattor under tre styckern villkor; öppna ögon, stängda ögon och weight-bearing feedback. Man undersökte sedan korrelationen mellan avståndet från CoM till CoP och CoMacc i både anterioposterior (A/P) riktning samt medio-lateral (M/L) riktning och analyserade datan med trevägsvariansanalys (ANOVA). Resultat: Resultatet visade att det fanns en signifikant interaktionseffekt mellan villkor och position i M/L-riktning. I A/P-riktning fanns det en signifikant interaktionseffekt mellan grupp och position samt villkor och position. Slutsats: Resultatet innebär att IPM är kinetiskt validerat i A/P-riktning sett till hela kroppen men inte på den amputerade sidan. Hur det intakta benet förhåller sig till IPM för amputerade är tvivelaktigt. / Background: It is known that transfemoral prosthesis users lack normal balance control and are more likely to fall. Research on this topic is insufficient. The Inverted Pendulum Model (IPM) is a commonly used biomechanical model for assessment of balance and postural control for healthy individuals based on an assumption that Center of Pressure (CoP) and Center of Mass (CoM) are inter-dependent. The aim of the study is to validate IPM kinetically for transfemoral prosthesis users. Method: Amputees (n=5) and a control group (n=5) participated. During data collection, participants stood on two force plates with eyes open, eyes closed and with weight-bearing feedback. Correlation of the distance CoP-CoM and CoMacc were calculated for anteroposterior and mediolateral directions and evaluated with three-way ANOVA. Result: Results showed significant interaction effects between condition and position plus group and position in anteroposterior direction and condition and group in mediolateral direction. Conclusion: Results indicate kinetic validity of IPM for transfemoral amputees when looking at the whole body but not at the amputated side in the A/P direction. Kinetic validity of IPM for the intact leg is questionable.
47

Une approche évolutionniste de la réduction des pesticides en viticulture / An evolutionary approach for pesticide reduction in grape growing

Alonso Ugaglia, Adeline 13 December 2011 (has links)
Les atteintes à l’environnement causées par un usage important de pesticides remettent en cause lemodèle productif actuel en viticulture d’appellation. Un cadre d’analyse évolutionniste est mobilisépour comprendre le manque de changement de pratiques phytosanitaires dans ce secteur malgrél’augmentation des pressions réglementaire et sociétale ces dernières années. Après avoir analysé lelock-in des viticulteurs vis-à-vis de l’utilisation des pesticides, nous appréhendons les nouvellespratiques grâce au concept d’innovation environnementale. En nous basant sur une enquête et unmodèle évolutionniste, nous montrons que l’IPM, en tant qu’innovation de processus, permet deréduire de manière significative les quantités de pesticides employées le long de trajectoiresgagnant-gagnant, mais que l’absence de compétences spécifiques dans les exploitations entrave sonadoption. Nous mettons ainsi en évidence l’importance des processus d’apprentissage pour laréduction des pesticides en viticulture. En l’absence de R & D formalisée, les viticulteurs ont besoind’un accompagnement spécifique et d’organismes de conseil agricole structurés localement pourrelever le défi de produire des vins rentables et respectueux de l’environnement. Les politiquespubliques en construction peuvent donc s’appuyer sur ces résultats pour impulser le changementattendu dans un délai raisonnable. / The environmental damage caused by the intensive use of pesticides challenges the current production model in appellation wine growing. We mobilize here an evolutionary framework to understand the lack of change in vineyard phytosanitary protection despite increasing regulatory and social pressure in recent years. After analyzing grape growers’ pesticide lock-in, we consider new protection practices via the concept of environmental innovation. Our case analysis and evolutionary model allow us to show that IPM could significantly reduce pesticide use along win-win trajectories, but also that the lack of specific implementation know-how in farms hampers its adoption. We therefore highlight the importance of learning processes for pesticide reduction in grape growing. In the absence of formal R & D, growers need specialized advice and structured extension services to meet the challenge they face: producing profitable and environmentally friendly wines. Public policies can therefore be based on this result to drive the expected change in a reasonable time.
48

School IPM

Gouge, Dawn H., Smith, Kirk A. 02 1900 (has links)
No description available.
49

Subterranean Termite (Isoptera: Rhinotermitidae) Mortality Due to Entomopathogenic Nematodes (Nematoda:Steinernematidae, Heterorhabditidae)

Weeks, Brian, Baker, Paul 02 1900 (has links)
Two species of entomopathogenic nematode were studied in terms of their survivability, detectability by the subterranean termite Heterotermes aureus, and their ability to induce mortality in H. aureus. Heterorhabdidtis bacteriophora (Poinar) and Steinernema carpocapsae (Weiser) are nematodes sold commercially as a means of biological control for termites. We used a laboratory method to determine how effective these nematode species might be under field conditions. Tests showed a difference in the survivability between nematode species and also ability to kill termites. It was also shown that H. aureus had no ability to detect either nematode species when given a choice between arenas infested with nematodes and not. Though nematodes might have some limited capacity for termite control, those considering using nematodes to control Heterotermes aureus may want to consider the species of nematode before making a purchase.
50

Survivability of the Subterranean Termite Heterotermes aureus When Exposed to Different Temperatures and Relative Humidity

Weeks, Brian, Baker, Paul 10 1900 (has links)
Survivability of Heterotermes aureus (Snyder) was tested under varying temperature and relative humidity regimes in laboratory incubators over seven day periods. Initial tests showed that RH had a strong influence on H. aureus survival. Survival was significantly higher (P<.05) at 90% RH than 50% RH when held at a constant temperature of 29.4°C. Four temperatures were tested at a constant RH of 90%. Survival was highest at temperatures of 19.4°C (91.8%) and 21.1°C (97.3%). Survival was significantly lower for the higher ranger temperatures of 29.4°C (91.2%) and 32.2°C (69.2%).

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