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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

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
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

EFFECTS OF ANAEROBIC SOIL DISINFESTATION COMBINED WITH BIOLOGICAL CONTROL ON ROOT-KNOT NEMATODE AND LETTUCE DROP

Sanabria, Andres, SANABRIA January 2018 (has links)
No description available.
44

A comparative study of the population dynamics of four Amaranthaceae species

Schwartz, Lauren Michele 01 August 2015 (has links) (PDF)
Some of the most problematic agricultural weeds found in the Midwest United States are found in the Amaranthaceae family, such as Amaranthus palmeri and A. tuberculatus. These summer annual weeds are troublesome due to their competitive ability, high seed production, and resistance to herbicides from several modes of action which complicates management in field crops and has led to significant yield loss. Achyranthes japonica and Iresine rhizomatosa are two perennial species in the same family as A. palmeri and A. tuberculatus that occur in similar habitats as one another, but differ in invasiveness. Achyranthes japonica is a non-native, invasive species that is becoming a threat to forested areas and has been observed along agricultural field margins. Iresine rhizomatosa also occurs in forest habitats but is an endangered species in Illinois. This research seeks to determine the comparative life history and relative competitiveness of closely related weedy species when challenged with a dominant species. Specifically, select, closely related weedy species in the Amaranthaceae plant family that occur in southern Illinois were compared, i.e., Achyranthes japonica, Amaranthus palmeri, Amaranthus tuberculatus, and Iresine rhizomatosa. The first study examined the life history characteristics of A. japonica in regards to survivorship, growth and fecundity at two sites in southern Illinois (Chapter 2). Achyranthes japonica is a relatively new invasive species that has been poorly studied. This experiment showed that regardless of site, environmental factors had a significant effect on seedling emergence and seed viability, which decreased from 2012 to 2013 during a drought year and rebounded from 2013 to 2014 following flooding. On average, individuals at the driest site had higher performance and fecundity, regardless of year. The second experiment tested the relative competitive effect and response of the Amaranthaceae species to Glycine max, first in a greenhouse study that tested shading and nitrogen resource drawdown for each species, and second in a controlled field experiment that tested intraspecific competition (Chapter 3). In addition, A. japonica seedlings were planted as either unmanipulated seedlings (uncut A. japonica) or as a seedling cut back to the soil surface at the four-node stage (cut A. japonica) at which point seedlings have reached a perennial growth stage. The greenhouse experiment showed that the four species each drew down light significantly, but not nitrogen. Shading decreased the aboveground biomass of the species in comparison to unshaded controls. Supplemental nitrogen, however, increased the aboveground biomass of A. palmeri and A. japonica. The supporting controlled field experiment showed that the competitive response of the weed species to the presence of G. max showed a reduction in height compared to the weed species grown in monocultures. Glycine max and the weed species, except I. rhizomatosa, showed a similar competitive effect and response when aboveground biomass was measured. Achyranthes japonica attained the highest belowground biomass when grown as a monoculture and in the presence of G. max. A competitive effect ranking was determined to be A. palmeri > A. tuberculatus > cut A. japonica = uncut A. japonica = I. rhizomatosa with the competitive response ranking being the inverse. The third study implemented an integral projection model (IPM) to determine the population growth rate of each species and how they compared to one another (Chapter 4). This experiment showed that A. palmeri, A. tuberculatus and A. japonica each had a population growth rate greater than one indicating rapidly growing populations. By contrast, I. rhizomatosa had a population growth rate less than one indicating a declining population. The results suggest that A. japonica has not yet shown the ability to escape management strategies in agricultural fields implemented by farmers, but it is still an aggressive invasive species that farmers and land owners need to be able to identify. This species has many similar characteristics to the Amaranthus species, such as the ability to colonize in areas with limiting resources, continual flushes of germination throughout the growing season, the ability to outcompete other weed species, and high fecundity but, A. japonica also is a perennial species that can withstand removal of shoot material and has a high germination rate. Based on these results, only early detection and rapid response methods should be relied on to keep these species out of areas in and around agricultural fields. Iresine rhizomatosa’s performance in these studies was consistent with its rarity.
45

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
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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