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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.
1

Management of insect pests of farmed-stored maize in Kenya, with particular reference to Prostephanus truncatus (Horn)

Giles, Peter H. January 1998 (has links)
No description available.
2

Effects of Defoliation in Soybeans and Susceptibility of Soybean Loopers to Reduced Risk Insecticides

Owen, Lucas Neil 12 May 2012 (has links)
Insect defoliation thresholds were reevaluated to determine their effectiveness during vegetative and reproductive stages of soybean. Field experiments were planted with maturity group IV soybeans and subjected 17, 33, 66, and 100% defoliation during R3, R5, and R6 growth stages. In addition to different amounts of defoliation for each growth stage, defoliation occurring within different portions of the plant canopy was also evaluated. Results of this experiment confirmed that soybeans during R3 and R5 stages are more susceptible to yield loss at high levels (>57%) of defoliation than R6 growth stage. However, yield loss was not significantly different below 57% defoliation. No significant yield difference was observed from defoliation occurring in the top or bottom part of the canopy. Yield loss from various levels of defoliation during the vegetative stages was significant at V6. No yield loss was observed from defoliation during the V3 growth stage. Both maturity group IV and V soybeans behaved similarly to each level of defoliation. Results from these experiments were used to determine dynamic economic injury levels for each growth stage based on yield loss equations, value of the crop, and cost of control and can be used to make insecticide application recommendations based on the amount of defoliation at a particular reproductive growth stage. Soybean looper, Chrysodeixis includens (Walker), is an economic pest of soybeans that has developed resistance to several insecticide classes. New insecticides have recently been labeled for control of lepidopteran pests in soybeans, including soybean loopers. Field reference strains were collected in 2010 and 2011 from soybean fields in Mississippi and Louisiana and subjected to insecticide incorporated diet treated with flubendiamide, chlorantraniliprole, and methoxyfenozide. Susceptibility of soybean loopers to flubendiamide and chlorantraniliprole did not differ. However the overall susceptibility to methoxyfenozide was greater than chlorantraniliprole. Diet incorporated assays determined a 9.4 fold variation in susceptibility to flubendiamide among the seven soybean looper populations tested. Variation to chlorantraniliprole was 6.25 fold and variation for methoxyfenozide was 5.37 fold. These data can be used as a benchmark for referencing future soybean looper populations in Mississippi and Lousiana.
3

Possible tritrophic consequences of high levels of host plant resistance (as in transgenic resistance) to aphids in Brassicaceae

Ganguly, Subhendu January 1999 (has links)
No description available.
4

Fungus Gnat Integrated Pest Management

Bealmear, Stacey 12 1900 (has links)
4 pp. / This publication will explain what fungus gnats are and how to manage them.
5

How to Bug Proof your Home

Gouge, Dawn 07 1900 (has links)
32 pp. / Bugs @ Home series; Revised / How to keep bugs out and reduce your utility costs!
6

Practical Methods of Controlling Bed Bugs at Home

Li, Shujuan, Gouge, Dawn, Fournier, Al 09 1900 (has links)
4 pp. / Bed bugs can cause anxiety, bite reactions, and financial hardship. The University of Arizona Community IPM Program and partnering research institutions are working to battle the recent bed bug resurgence. Researchers hope to determine the real social cost of bed bugs, as well as the significant causes of infestations. Integrated Pest Management (IPM) approach is the most likely strategy to result in successful elimination of bed bugs.
7

Integrated pest management of the banana weevil, Cosmopolites sordidus (Germar), in South Africa

De Graaf, Johan 10 July 2008 (has links)
The banana weevil, Cosmopolites sordidus, is an economical pest of Musa, distributed to most areas where the crop is grown. The beetle larvae produce feeding tunnels in the pseudostem and rhizome, reducing bunch weight and causing toppling or snapping of plants. In developing an integrated pest management system for South Africa, specific aims of the study were to quantify the genetic diversity of the species around the world, investigate the population dynamics of the insect, determine the potential of semiochemical mass trapping, elucidate the efficacy of cultural and chemical control methods and establish economic thresholds for the banana weevil on Cavendish bananas in South Africa. Pest status of the insect is variable around the world, and may be influenced by genetically distinct populations of the weevil. Six populations from four countries were sampled: Australia, Costa Rica, South Africa (South Coast, North Coast and Tzaneen) and Uganda. DNA was isolated from 12 individuals per population and subjected to amplified fragment length polymorphism (AFLP) analysis. The AFLP analysis involved DNA restriction with EcoRI and PstI enzymes, ligation of adapters, and a pre-selective and five selective PCR amplifications. Empirical analysis of the AFLP fingerprints showed that, within populations, genetic diversity varied from 16-53%, with the South Coast and Tzaneen/Australian populations the least and most variable, respectively. The coefficient of gene differentiation showed that the Tzaneen population were the most differentiated from the South Coast population, while the South and North Coast populations were the most similar. All the populations showed statistically distinct marker frequencies, except for the Costa Rican and South and North Coast populations, which were similar. Based on the simple mismatch coefficient, a neighbour-joining tree showed the Australian, Ugandan and South African coastal populations produced monophyletic groups, while the South African Tzaneen population were removed from the other populations and presented an ancestral state. The population dynamics of the insect was investigated over two seasons and at three locations in the South Coast of KwaZulu-Natal. Adult activity was monitored with semiochemical (Cosmolure®) baited pitfall traps. Traps were moved monthly to a random independent location, or left in situ for the duration of the experiment. The ontogeny was determined by dissecting felled plants and toppled plants (up to 2-week-old fresh residues), and harvested plants visually classified as an early and a late rotting stage (decayed residues). Replicated, randomised block designs were used in the experiments. The adult beetles were sexed and the percentage females with eggs and the number of eggs per female were recorded. Larval head capsule widths were measured with an electronic caliper. Ambient temperature and precipitation (rainfall + irrigation) were measured on site. Weevils were active throughout the year and mainly collected in stationary traps, with a collection peak in May and high numbers in early spring and late autumn/early winter. The activity was usually a negative and a positive function of ambient temperature and corrected rainfall, respectively. Eggs per female and percentage females with eggs were reduced during winter and a positive function of ambient temperature. The beetles sampled from plant material represented an equal sex ratio, while the pheromone traps collected a female biased sex ratio during spring and autumn/early winter. The beetle had overlapping generations with a peak of adults and larvae in autumn and late summer, respectively. Adults were mainly associated with decayed residues while larvae were mostly found in freshly toppled plants. Adults were the main over-wintering stage. The earliest larval instars were usually sampled during autumn. The data suggested that the beetle is multivoltine in the study areas and provided valuable information for the optimal management of the insect pest. Semiochemical adult trapping methods were compared in field trials using a randomised block design. Pseudostem traps, pitfall traps containing a pheromone (either Cosmolure® (Pheromone A) or Cosmolure+® (Pheromone B)), and unbaited pitfall traps (control), were compared over 5 weeks during all seasons along the Southeast coast of South Africa. Pseudostem traps treated with an insecticide, and rhizome traps were included as additional treatments in autumn. In summer two treatments were also added: individual suspension of both pheromones above a pitfall trap either in combination with or without a pseudostem trap. The adult beetles were sexed, and the number of internal eggs noted. Pheromone A proved to be the most effective of the different traps. Grouping of the pheromones resulted in a synergistic response, while combining the pseudostem did not enhance trap efficacy. The different plant material traps and the control were usually equally effective in catching weevils. Plant material traps caught greater numbers of fecund females, but pheromone traps captured a higher proportion of females. Treatment effects were much less pronounced in summer, and compared to a pseudostem trap, pitfall traps were the most efficacious during spring. Compared to conventional pseudostem trapping, Pheromone A pitfall traps should be optimally applied during spring in South Africa. Cultural control methods were investigated over 2 years at an ongoing trial in the Southern KwaZulu Natal, South Africa. Harvesting at ground level and dissection of remnants, and covering of the mat with soil and moving debris to the inter-row, were compared to a positive control that involved treatment of plants with a registered pesticide, and a negative control that involved harvesting at approximately 150 cm with no soil or sanitation amendments. Yield, weevil damage and pseudostem girth of plants were measured from August to November annually, while adult beetle densities were assessed over 4 weeks in October/November and April. Nematode samples were analysed in October/November every year. Damage parameters included the Coefficient of Infestation, the Percentage Coefficient of Infestation (PCI) at two intervals, the summed PCI value, the percentage cross sectional damage of the central cylinder (XI) and cortex, and the mean cross sectional damage percentage (X mean). A replicated block design was used in the experiment. The parameters were similar before the onset of the trial. Fruit yield and plant girth, corrected by nematode densities, were not significantly different in any treatment, nor were the nematodes controlled. Soil cover and recession of remnants was the only effective treatment, significantly reducing the Coefficient of Infestation, but not the adult density or any other damage parameter. The former showed promise as a cultural control method because it only needs to be applied seasonally and reduced the XI, the damage parameter most closely related to yield, by 14.18%. The weevil is difficult to control, and chemical control arguably provides the best opportunity to manage the pest. The efficacy of injecting bifenthrin, chlorpyrifos, fipronil, imidacloprid, oxamyl and water (control) into residual banana plants was determined. The chemicals were administered every even numbered month over 2 years at two locations in Southern KwaZulu-Natal, South Africa. Yield, weevil damage and pseudostem girth of plants felled from August to October were measured, while adult beetle densities were assessed over 4 weeks in October and April. Nematode samples were analysed in October every year. Damage parameters included were similar to that of the cultural control trial. Replicated block designs were used in the experiments. The parameters were similar before the onset of the trial. Fruit yield and plant girth, corrected by nematode densities, were not significantly increased after chemical applications, nor were the nematodes controlled. Fipronil and imidacloprid were highly effective against C. sordidus, minimising damage to the periphery, cortex and central cylinder of the rhizome and significantly reduced adult density. Fipronil caused a 95% and imidacloprid a 100% reduction in the XI. Injection of fipronil and imidacloprid provides an optimal chemical strategy in an integrated pest management programme for the banana weevil. Economic thresholds of the insect were investigated on bananas at four locations in the South Coast of KwaZulu-Natal. Yield (bunch weights) and larval damage to felled plants were measured from August to October in 2003, while adult densities were assessed over 4 weeks in October 2003. Nematode samples were collected and analysed in October 2003. Damage parameters included were similar to that of the cultural control trial. Replicated block designs were used in the experiments. The economic-injury level (EIL) for chemical and cultural control was calculated. Nematode densities did not influence the yield of plants. The XI was the best predictor of yield, but under certain conditions X mean was the most important. Chemical control showed the lowest EIL, with more than 1 and 7% damage to the central cylinder when applying fipronil and imidacloprid, respectively. The EIL for cultural control was more than 11% damage to the central cylinder. A recommendation algorithm, considering all the findings of the individual studies, is provided for IPM of the banana weevil in the South Africa. The potential use of microbial and invertebrate (especially parasitoids) biological control and semiochemical mass trapping of the weevil requires further research. Long-term research should focus on host resistance, and weevil damage to the central cylinder can serve as indicator of susceptibility of Cavendish bananas. / Thesis (PhD (Entomology))--University of Pretoria, 2008. / Zoology and Entomology / unrestricted
8

Virginia Integrated Pest Management Expert for Wheat

Warren, Peter Lane 20 July 1999 (has links)
The Virginia Integrated Pest Management Expert for Wheat was designed to combine the best available information regarding wheat pest management of disease pathogens, weeds, and insects into a decision support system that would provide potential outbreak risk and pest control information to the Comprehensive Resource Planning System (CROPS). In addition, the system stands alone as an educational tool for farmers and Extension personnel. This is a rule-based system developed on the Microsoft Windows platform. Knowledge about crops and pest management is represented in the form of IF/THEN rules, demons, and "when-changed" methods. The inference engine analyzes specific crop system information entered by the user to determine potential risks of outbreak for wheat crop pests common to Virginia. These potential outbreak risks are presented as low, medium, and high levels of risk and are presented for each of 15 pests of wheat in Virginia. The system was evaluated using thirty random cropping system scenarios. By comparing expert system output with output from human experts, it was shown that the expert system agreed with human expert opinions in 84 percent of the decisions made. Statistical analysis of the insect pest data showed that there was no significant statistical difference between the distribution of the human expert predictions and the expert system predictions. Statistical analysis of the disease pest data showed that there were some significant statistical differences between the distribution of the human expert predictions and the expert system predictions. / Master of Science
9

Factors Affecting Integrated Pest Management Adoption and Pesticide Use in Kenyan Vegetable Farmers

Hasan, S. M. Muntasir 07 September 2017 (has links)
This study identifies the factors influencing adoption of IPM practices and number of pesticide applications in vegetable farmers in Kenya. The sample size for this study includes 263 vegetable farmers. The survey was conducted in four counties of Kenya: Nyeri, Tharka Nithi, Nakuru and Bomet. The vegetables considered in this study are tomato, cabbage and French beans. Different econometric tools are used to analyze adoption of IPM practices and pesticide application for vegetables. It is found that experience in vegetable cultivation and number of livestock owned have a positive impact on the adoption of IPM practices. However, distance to the nearest town has a negative impact on adoption. Moreover, the number of times pesticides are applied to vegetables also declines as distance of the household from the nearest town increases. Farmers whose crops face less stress from insects and disease tend to apply pesticides fewer times as well. Results from this study indicate that being close to town is important for agricultural activities in general. Being farther away not only reduces the probability of IPM adoption but also reduces pesticide application. / Master of Science / This study identifies the factors influencing adoption of IPM practices and number of pesticide applications in vegetable farmers in Kenya. The sample size for this study includes 263 vegetable farmers. The survey was conducted in four counties of Kenya: Nyeri, Tharka Nithi, Nakuru and Bomet. The vegetables considered in this study are tomato, cabbage and French beans. Different econometric tools are used to analyze adoption of IPM practices and pesticide application for vegetables. It is found that experience in vegetable cultivation and number of livestock owned have a positive impact on the adoption of IPM practices. However, distance to the nearest town has a negative impact on adoption. Moreover, the number of times pesticides are applied to vegetables also declines as distance of the household from the nearest town increases. Farmers whose crops face less stress from insects and disease tend to apply pesticides fewer times as well. Results from this study indicate that being close to town is important for agricultural activities in general. Being farther away not only reduces the probability of IPM adoption but also reduces pesticide application.
10

Adoption and Impacts of IPM for Cambodian Rice Farmers

Jackson, Sydni Blaine 15 November 2017 (has links)
This study evaluates the adoption and impacts of Integrated Pest Management (IPM) adoption for rice in Cambodia. Extent of adoption and characteristics of adopters are discovered. Farmers are considered high adopters of IPM if they used two non-pesticide or minimal-pesticide practices to control rice insect, disease, weed, or rodent pests in the last twelve months; farmers are considered low adopters if they used one practice; farmers are considered non-adopters if they used zero practices. IPM practices include pest-resistant variety; stale seedbed (sequential harrowing or harrowing followed by a non-selective herbicide); apply Trichoderma on seeds or seedlings, no insecticide spray for the first 40 days; apply bio-pesticides such as neem, Bt, and metarhizium, and Beauvaria; Sarcocystis bait for rodents; hand weeding at recommended growth stage; and/or another practice specified by the farmer. Out of 394 farmers surveyed, 40 (10.15%) were found to be high adopters, 228 (57.86%) were found to be low adopters, and 126 (31.97%) were found to be non-adopters of IPM. IPM practices currently include mostly hand-weeding and no spray for 40 days; few other practices were adopted. Our study reveals a need for broader education on rice IPM throughout Cambodia. The high frequency of pesticide applications among rice farmers, the finding that adoption of IPM was not found to have a meaningful influence on the number of pesticide applications, and the finding that less than one-quarter of farmers in our study have received training on IPM reveal the need for increased knowledge of IPM in Cambodia, and the need for future education on IPM to focus on reducing pesticide use. / Master of Science / This study evaluates the adoption and impacts of Integrated Pest Management (IPM) for rice in four provinces in Cambodia. IPM is an ecologically-friendly pest management philosophy that offers alternatives to reliance on harmful chemical pesticides. Farmers are divided into groups of high adopters, low adopters, and non-adopters depending on the number of IPM practices used. Proportion and characteristics of adopters, frequency and type of IPM practices, and scope of IPM training in the region are discovered. Determinants of adoption and the effect of adoption on level of pesticide use on rice are analyzed using econometric analysis. Out of 394 farmers surveyed, 40 (10.15%) were found to be high adopters, 228 (57.86%) were found to be low adopters, and 126 (31.97%) were found to be non-adopters of IPM. Adopters primarily use only two types of IPM practices. Less than one-quarter of farmers in our study have received training on IPM. Farmers who have more years of experience in rice cultivation, and farmers who consider agricultural extension a top source of agricultural information are more likely to adopt IPM. Farmers who have more family members who are able to work, and farmers who consider input suppliers a top source of agricultural information are less likely to adopt IPM. Adoption of IPM was not found to meaningfully influence the number of pesticide applications on rice. Our study reveals the need for increased training on rice IPM in Cambodia, and the need for future IPM education to focus on reducing pesticide use.

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