Call number: LD2668 .T4 1956 A43 / Master of Science

Doctor of Philosophy / Department of Physics / Thomas W. Phillips / The emergence of heritable high-level resistance to the fumigant gas phosphine in stored-product insects is of grave concern to many grain growing countries around the world. The research reported in this dissertation was designed to determine the presence of phosphine resistance in 34 field collected populations of Rhyzopertha dominica (F.) from the United States and Canada, the potential to control resistant R. dominica populations utilizing high dose and longer exposure time strategies, and to develop a rapid assay for phosphine resistance detection. Using a discriminatory dose assay called the FAO number 16 method, adult R. dominica were sampled and subjected to a phosphine dose of 20 ppm for a fumigation exposure period of 20 h to distinguish a susceptible R. dominica adult by death from a resistant beetle that survives the treatment. Results from the study showed that 32 out of the 34 geographic populations surveyed had beetles resistant to phosphine, and the frequency of resistance varied from 97% in a population from Parlier, California to 0% in beetles from both Carnduff, Saskatchewan and Starbuck, Manitoba. A 20-hour dose response assay was used to characterize the level of resistance by calculating the resistance ratio factors using beetles from a laboratory susceptible strain and those from five of the populations sampled. This resistance ratio (RR) was based on the ratio of LC50 (estimate for the concentration to kill 50% of a test group) in the sampled population to the LC50 for the susceptible strain. The highest RR for the five resistant populations was nearly 596-fold in beetles from Belle Glade, Florida, which represented the “strong” resistance phenotype, whereas the lowest RR in that group was 9-fold in Wamego, Kansas, representing the “weak” resistance phenotype. Manipulation of concentration and exposure periods can be utilized to manage strongly resistant R. dominica populations. The effect of several phosphine concentrations and fumigation exposure periods were assessed on progeny of mixed life stage colonies of the strongly resistant R. dominica. A 48 hours dose response assay was carried out on these two strongly resistant populations to re-characterize their levels of resistance. Results from this assay showed that a phosphine dose of 730-870 ppm could control all resistant adult R. dominica. Additionally, phosphine concentrations ranging from 400-800 ppm phosphine for 96 hours completely killed mixed life stage colonies of strongly resistant lesser grain borers from the two populations studied. Lastly, fumigations done beyond 4 days at phosphine concentrations between 450-700 ppm controlled all phosphine resistant populations of lesser grain identified from our previous work. Phosphine applied at high concentrations is known to elicit a knockdown effect that can vary between susceptible and resistance grain insects. Using 18 of the 34 R. dominica populations this study sought to determine among three knockdown time (KT) techniques which method had potential to be utilized in an effective rapid assay for phosphine resistance in R. dominica. Adult R. dominica were exposed to a high concentration of phosphine (3000 ppm) to assess the time to knockdown 50%, 100% of a group of ten insects and that of single insects from the 18 geographically distinct populations vis a vis the resistance frequencies using the FAO method. KT100 quick test was better than the KT50 and Ktsingle, because bioassays were able to clearly distinguish among susceptible, weak and strong resistant individuals. Time for KT100 from susceptible populations did not exceed 30 minutes, while resistant populations had KT100 times above 30 min, with strong-resistant populations times longer than 100 min.

Doctor of Philosophy / Department of Grain Science and Industry / X. Susan Sun / With continued population growth, more food production will be required with lower resource inputs. A significant drain on resources is post-harvest loss due to insects, which results in loss of product, quality and market access, and increased grain spoilage. Aeration and fumigation are key tools to control insect growth in stored grains and grain foods. The implementation of aeration strategies in Australia is made difficult by the warm subtropical climate, meanwhile the success of fumigation is being threatened by the spread of insect resistance to the fumigant phosphine. This dissertation project seeks to improve the understanding of aeration and fumigation by modifying the Maier-Lawrence (M-L) 3D ecosystem model by adding insect growth equations and quantifying fumigant loss from sealed bulk grain silos. The improved model was used to examine aeration under Australian conditions, validate its capability to accurately describe fumigant concentrations during silo fumigation, determine the extent to which fumigations are influenced by operational variables and environmental conditions, and validate its capability to describe fumigant concentrations post-fumigation in order to investigate the time needed to clear a grain storage silo of fumigant in order to assure worker safety. Six aeration strategies were evaluated under Australian conditions. Of these strategies, two were found to be effective in lowering temperatures, i.e., fans were turned on when ambient temperature was less than 20oC, and less than internal grain temperature. The strategy based on temperature differential was the most effective because it cooled the interior of the grain mass with the least amount of energy (using the fewest fan run hours, and reaching 15oC an average of 11 days after than the fastest strategy). Using a 0oC temperature differential was the most effective strategy in terms of reducing insect growth. The expanded (M-L-P) model was then validated based on experimental fumigant concentrations. The model was effective in reproducing average fumigant concentrations and fumigant trends vertically through the grain mass, but was not able to reproduce lateral fumigant variations. Verifications of the model with two different periods of phosphine release (i.e., 24h and 30h) were tested. Based on a 24h phosphine release period the predicted Ct-product differed from the experimental value by 0.9%. A 30h release period predicted a Ct-product that differed by 4.3% from the experimental value but it was more accurate during the times of highest concentration. Increases in leakage reduced fumigant concentrations, but the size of the effect decreased as leakage grew. Increasing temperature and wind speed in the model led to decreased phosphine concentrations, with temperature changes having a more significant impact overall than wind speed changes for the conditions investigated. Decreasing silo surface area to volume ratio dampened the impact of changing weather conditions on phosphine concentrations. A fumigant venting experiment was conducted in a silo at Lake Grace, Australia, to investigate full scale desorption. Two equations estimating fumigant desorption were tested, with an average of 65.5% and -86.3% error. The length of venting periods was simulated to quantify hours needed to mitigate hazardous conditions. For the scenarios investigated 10 to 24 h of venting were needed to reduce residual fumigant concentration below 0.3 ppm depending on simulation assumptions.

Dry-cured hams often become infested with ham mites (Tyrophagus putrescentiae) during the aging process. Methyl bromide has been used to fumigate dry cured ham processing plants and is the only known fumigant that is effective at controlling ham mite infestations. However, methyl bromide will be phased out of all industries by 2015. This research was designed to 1) determine the efficacy of phosphine fumigation at controlling ham mites and red-legged beetles and its impact on the sensory quality and safety of dry cured hams, and 2) to develop and evaluate the potential of using food-grade film coatings to control mite infestations without affecting the aging process or sensory properties of dry-cured hams. Fumigation trials were conducted in simulated ham aging houses and commercial ham aging houses. Mite postembryonic mortality was 99.8% in the simulated aging houses and >99.9% in commercial aging houses two weeks post fumigation. Sensory tests with trained panelists indicated that there were no detectable differences (P>0.05) between phosphine fumigated and control hams. An analytical method was developed to determine phosphine concentration in ham. In addition, residual phosphine concentration was below the legal limit of 0.01 ppm in ham slices taken from phosphine fumigated hams. Coating trials were conducted on ham cubes and slices. Cubes coated with xanthan gum+20% propylene glycol and carrageenan/propylene glycol alginate+10% propylene glycol were effective at controlling mite infestations under laboratory conditions. Barrier properties (water vapor permeability and oxygen permeability) were measured to estimate the impact of coatings during the aging process. It was evident that carrageenan/propylene glycol alginate were permeable to moisture and therefore could potentially be applied to the hams during the aging process.

Successive cropping of two vegetable crops grown on the same site in one season utilizing trickle irrigation, plastic mulch, and soil fumigation was performed in two separate experiments. In 1980, cabbage (Brassicae olericea L. var capitata cv. Market Prize) was followed by tomato (Lycopersicon esculentum Mill cv. Pik Red). In 1981, cabbage was followed by broccoli (Brassicae oleracea L. var italica cv. Green Duke). Double cropping increased the annual productivity of the research plots both years and decreased production costs by 35% compared to conventional single cropping systems. Early spring planting of the first crop was essential for economic production of the second crop. Trickle irrigation increased yields of all crops grown and was the factor most responsible for yield response both years. Black plastic mulch increased yields of tomato and total yields in 1980 but cole crops showed no significant yield response to mulch either year. No difference in crop yield resulted from soil fumigation either year. Increased production costs have caused growers to seek improved methods to offset risks and costs involved. Trickle irrigation can reduce the risks involved in producing vegetables and is particularly suited to multiple cropping on plastic mulch. / Master of Science

Orientador: Carlos Roberto Espindola / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-11T10:34:14Z (GMT). No. of bitstreams: 1 BrandaoJunior_Osvaldino_D.pdf: 9518735 bytes, checksum: f14c2b7993a0c94d6d3b6f2034ef17a3 (MD5) Previous issue date: 2005 / Resumo: Os teores de carbono e nitrogênio da biomassa microbiana (CBM e NBM), a respiração basal e o quociente metabólico (qCO2) da microbiota do solo foram avaliados em um LATOSSOLO VERMELHO Distroférrico da Região Norte do Estado do Paraná, sob diferentes sistemas de manejo de solo e das culturas. A área experimental foi instalada em 1988/1989, na Fazenda Experimental da Embrapa Soja, em Londrina, e é constituída de parcelas de mesmo tamanho (7,5m x 30,0m), que se diferenciam pelos diferentes sistemas de manejo do solo e das culturas; o delineamento experimental do ensaio foi em blocos ao acaso com quatro repetições. As coletas do solo, da camada de 0-10 cm, entre linhas de plantas, foram realizadas sempre pela manhã e o material foi coletado das parcelas sob três sistemas de manejo do solo, plantio direto (PD), preparo com cruzador (C) e plantio convencional (PC), sendo que todas as parcelas possuíam os seguintes sistemas de manejo das culturas: rotação (R - tremoço - Lupinus albus/milho - Zea mays/aveia preta - Avena strigosa/soja- Glycine max/trigo - Triticum aestivum/soja/trigo/soja) e sucessão (S - soja/trigo); desse modo, foram coletadas amostras de solo de seis tratamentos: PD (R e S), PC (R e S) e C (R e S). As amostras foram submetidas à análise da biomassa microbiana do solo pelos métodos de fumigação-incubação e fumigação-extração e os dados submetidos à análise de variância com o teste de Tukey (p<0.05). Pode se concluir que, em relação aos teores CBM e NBM avaliados pelo método de fumigação-extração, os maiores valores foram obtidos sob PD, seguidos do sistema de manejo com cruzador e pelo PC; resultados semelhantes foram obtidos pelo método de fumigação-incubação. Em relação aos resultados da respiração basal, os valores encontrados seguiram a seguinte ordem: PD > PC > C. Os qCO2 com e sem a indução por açúcar apresentaram comportamentos semelhantes, sendo que o sistema de PC apresentou maiores valores do que o sistema de PD e com cruzador. O menor qCO2 no PD indica a maior eficiência da microbiota do solo, implicando menor perda de carbono do solo e, conseqüentemente, maior acúmulo de carbono na matéria orgânica ao longo do tempo, nesse sistema. Não houve diferença estatística relacionada aos diferentes sistemas de manejo das culturas (R e S) / Abstract: The microbial biomass carbon (MB-C) and nitrogen (MB-N), basal respiration and metabolic quotient (qCO2) were evaluated in a Rhodic Eutrudox of the North Region of the State of Paraná under different soil and crop management systems. The experimental area was established in 1988/1989 at the experimental station of Embrapa Soja, Londrina, Paraná, and consisted of 7.5m X 30.0m plots under different soil and crop managements; the experimental design was in completely randomized blocks with four replicates. Soil samplings of the 0-10 cm superficial layer, between plant lines were always realized in the morning, from plots under three soil managements, no-tillage (NT), field cultivator (C) and conventional tillage (CT) each with either a crop rotation (R) (lupin - Lupinus albus/maize - Zea mays/black oat - Avena strigosa/soybean - Glycine max/wheat - Triticum aestivum/soybean/wheat/soybean) or crop sequence (S - soybean/wheat); therefore samples were taken from six treatments: NT (R and S), C (R and S) and CT (R and S). Soil samples were analyzed for microbial biomass using two methods, fumigation-incubation and fumigation-extraction and the data were submitted to the analysis of variance and the Tukey test (p<0.05). In relation to the MBC and MBN evaluated by the fumigationextraction method, the higher values were obtained with the NT followed by the management with the field cultivator and the CT; similar results were obtained with the fumigation-incubation method. In relation to the basal respiration, the values obtained followed the order NT > CT > M. The qCO2 with and without sugar induction were higher under CT, followed by the NT and the M managements. The lower qCO2 under NT indicates higher efficiency of the soil microbes, as well as lower losses of soil carbon resulting in higher accumulation of carbon in the soil organic matter with time. No statistical differences were observed related to the different crop systems / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola

44 pp. / Updated December 15, 2003

Master of Science / Department of Grain Science and Industry / Dirk E. Maier / Fumigation of stored grain is a common way to kill stored-grain insect pests. However, fumigating in unsealed structures is the leading cause of control failures and subsequent development of insect resistance. Sealing the storage structure is the only practical way to ensure a complete kill of all insects at all life stages. The cost, effort, and feasibility of sealing a U.S. corrugated steel silo during construction was evaluated and compared against an Australian sealed silo designed for fumigation. Gas monitoring and thermosiphon recirculation equipment was installed on both silos. Fumigation efficacy was evaluated using pressure half-life decay times, fumigant concentrations, insect bioassays, and grain quality data. Three fumigations with phosphine (PH₃) pellets or tablets and two with VAPORPH₃OS® cylinderized PH₃ and ProFume® cylinderized sulfuryl fluoride (SF) were performed in each silo for a total of ten experimental treatments. The Australian silo required 266 man-hours to construct and cost $180 for additional sealing, compared to 359 man-hours and $3,284 for constructing and sealing the U.S. silo. The Australian silo had a maximum pressure half-life decay time of 163 s versus 50 s for the U.S. silo. At application rates of 1.5 g/mᶟ of PH₃ both silos maintained an average concentration of approximately 0.28 g/mᶟ for 14 days. With thermosiphon recirculation the average minimum-to-maximum PH₃ concentration ratio in the U.S. silo was 0.52, compared to a ratio of 0.17 when fumigating without thermosiphon recirculation. Greater than 99% adult mortality was observed in all insect bioassays which included PH₃ resistant strains of R. dominica and T. castaneum. The average emergence from fumigated bioassays was 7 adult insects, compared to an average of 383 adults for the non-fumigated controls. Grain stored for 10 months in the sealed silos increased from approximately 11.5% to 17% m.c. in the top 0.3 m of grain, and decreased in test weight from approximately 77 to 65 kg/hL. Although the Australian silo retained higher fumigant concentrations than the U.S. silo, fumigations were successful in both. Long-term storage in sealed silos is a concern because grain quality can deteriorate due to condensation and mold in the top grain layer.

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The aim of this study is to experimentally measure performance characteristics of a compression ignition (CI) internal combustion engine using superheated ethanol vapor. The engine is a 1.3L inline 4 cylinder direct injection (DI) turbocharged compression ignition (CI) engine. While the engine will be fed with superheated ethanol as homogeneous fuel-air mixture through intake manifold, the amount of diesel fuel that the engine requires to run at idle will also be supplied in order to initiate combustion. Ethanol will be superheated using a new patented double heat exchanger has been manufactured by Prof. Dr. Demir Bayka, Dr. Anil Karel and Deniz &Ccedil / akar. The results will indicate if the suggested concept can be applicable.