Integrated pest management (IPM) is an approach to pest control which emphasizes the Integration of biological, cultural, and chemical control methods for optimal pest management. The purpose of this thesis is to empirically examine the level and distribution of net economic benefits of Extension IPM, and to assess the relative importance of socioeconomic factors in affecting the adoption of IPM in the states of Indiana, Virginia, Georgia, New York, North Carolina, Texas, Massachusetts, Mississippi and the Northwest region. Budgeting and hypothesis testing procedures are used to conduct a net returns analysis. Consumer-producer surplus analysis is used to assess IPM benefits to producers and consumers. Finally, a polychotomous logit model is used to assess the importance of socioeconomic factors affecting IPM adoption. The results of these analyses show significantly higher returns and less variability of returns per acre for users of IPM as compared to non-users. Moreover, consumers receive significant positive economic gains. However, pesticide cost and the variance of pesticide cost per acre increase with increasing levels of IPM use in several states but decrease in a few others. Gross farm income, percent family income from farming, frequency of contacts with Extension agents, and the education level of respondents are the most important factors related to adoption of IPM. A typical user of IPM is white, male, with at least some college education, has frequent contacts with Extension agents, has a relatively large farm, higher gross farm income, and a higher percent family income from farming. / Master of Science

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Sclerotinia sclerotiorum is a pathogen of crops grown in the muck soil regions of Quebec. Soil baiting tests indicated that the sclerotia of S. sclerotiorum are attacked and destroyed by the larvae of Bradysia coprophila and mycoparasites. Sclerotia with rinds partially damaged by the larvae were found to be more susceptible to mycoparasitism by Trichoderma viride. Increasing the organic matter content and porosity of soils resulted in increased damage to sclerotia when larvae were present. Studies conducted to determine if larvae could be reared on diets of various fungi and plant tissue showed that mycelia and sclerotia of S. sclerotiorum were the most successful food sources, followed by mycelia and sclerotia of Botrytis porri and Rhizoctonia solani. Adults produced on mycelia and sclerotia of Sclerotinia minor, Fusarium solani f. sp. pisi, and Botrytis cinerea seldom were fertile. Larvae generally failed to survive when reared on cultures of Trichoderma viride. Larval development occurred on all plants inoculated with the above pathogens but failed to occur on noninoculated healthy plants. Salivary gland secretions of the larvae were found to inhibit the germination of sclerotia. Analyses of the secretion determined that it contains 4.3% protein and had chitinase activity. Mechanically damaged and undamaged sclerotia exhibited an increase in eruptive mycelial germination when treated with 1.5 $ mu$g ml$ sp{-1}$ chitinase but germination decreased at 50, 100 and 150 $ mu$g ml$ sp{-1}$ chitinase concentrations. Noneruptive mycelial germination and carpogenic germination occurred when sclerotia were treated with acetate buffer and distilled water.

A four-year (1988 to 1991 inclusive) field and laboratory study was undertaken to determine and select the components that could be integrated to control the sorghum shoot fly, Atherigona soccata Rondani (Diptera: Muscidae), in Burkina Faso, West Africa. Nine approaches were investigated: (1) monitoring adult shoot flies; (2) sequential sampling based on egg and dead heart counting; (3) cultural practices (sowing dates and plant densities, intercropping sorghum-cowpea); (4) use of resistant cultivars; (5) use of natural insecticide from the neem tree Azadirachta indica A. Juss. (Meliaceae); (6) effects of intercropping sorghum-cowpea on the natural enemies of the shoot fly; (7) spider fauna in pure sorghum and intercropped sorghum-cowpea; (8) parasitism of the shoot fly by a larval parasitoid, Neotrichoporoides nyemitawus Rohwer; and (9) the biology of an egg parasitoid, Trichogrammatoidea simmondsi Nagaraja. These nine approaches were divided into four main components: (1) monitoring populations, (2) cultural practices, (3) natural and chemical pesticides, and (4) biological control that could be integrated to control the shoot fly. Among these components, monitoring populations (egg sampling), cultural practices, and use of natural pesticides could be utilised at the farmer level.

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Please read the Summary/Samevatting on pp 138-141 in chapter 6 of this document / Thesis (PhD (Plant Pathology))--University of Pretoria, 2006. / Microbiology and Plant Pathology / unrestricted

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The biology of Anisota senatoria J. E. Smith (Lepidoptera: Saturniidae) was examined through ecological studies of within-tree distribution and dispersion, and the influence of a tree growth regulator on development and survival. Biological characteristics examined egg mass size and development, pheromone attraction, response to blacklight traps, adult emergence, laboratory development, pupal mortality and comparison of first versus second generation development time, fecundity and amount of infestation. Within-tree distribution of life stages showed significant differences between low (1.7-3.6 min height), middle (3.7-5.5 m) and high (5.6-7.6 m) strata. Dispersion indices generated from Taylor’s power law showed aggregation was greatest among early instars, followed by third instars and late instars. A fixed level precision sampling plan was developed based on the number of eggs and early instars present in low strata. The tree growth regulator paclobutrazol significantly reduced Q. Phellos L., willow oak, growth, especially one and two years posttreatment. One year posttreatment, paclobutrazol treatments significantly slowed development and decreased survival of early instars, but the opposite relationship was found with late instars. Behavior studies showed that increased A. senatoria survival occurred with increased group size. Laboratory and field experiments revealed critical group sizes for survival of 1-3 larvae and between 25-50 larvae. Anisota senatoria defoliation impact and frass were measured. Growth and root starch were significantly reduced with increased defoliation in Quercus palustris Muench., pin oak, but Q. phellos root starch was not reduced. Reduction in starch content in Q. palustris may have been related to additional stress factors. Landscape fabrics were a reliable sampling method for frass. Frass was used as a method for differentiating larval instars and predicted defoliatioonf Q. palustris. An integrated pest management (IPM) program was developed that included information on native parasites, host plant preference, a citizen survey, and aesthetic indicators. Four egg parasite species including an Aprostocetus new species, five larval parasites and eight hyperparasites were collected. Host plant preference experiments indicated that Q. alba L., white oak, was least preferred by A. senatoria. A citizen survey provided a framework for designing an IPM program. Monitoring and establishing an aesthetic injury level of 25% defoliation decreased pesticide volume without an attendant increase in damage. The number of egg masses (threshold) that caused 25% defoliation ranged from one to nine. / Ph. D.