xx, 271 leaves, 28 leaves of plates (3 col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.) Dept. of Agronomy, University of Adelaide, 1981

Thesis (M.A.)--Carleton University, 2002. / Includes bibliographical references (p. 72-78). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1944. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 165-167).

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.

Phenolics in finger millet (FM) grain, including tannins, may impact significantly on its antimicrobial properties, functionality and health-promoting potential. Unfortunately, the location of tannins in the grain is unknown and there is limited information on the influence of variety on grain phenolic composition and antioxidant activity (AA). The effect of phenolics in FM grain on its malt fungal load and on the functional quality of its food products, including baked goods, is barely known. Twenty two FM grain types of varied visual kernel colour were analysed to determine the influence of grain type on phenolic composition, AA, and tannin localisation in the grain. Condensed tannins, anthocyanins and flavan-4-ols were detected. Light coloured grain types had no tannins and had much lower total phenolics (TP) relative to the pigmented types, and types that stained black with the Bleach test had much higher tannin content and much higher AA. The grains that stained black with the Bleach test and had high tannin content (0.60 to 2.08 mg catechin eqivalents/100 mg, db) had a dark coloured testa layer, indicating that the tannins were located in that layer. The results indicate that occurrence of tannins in FM is a varietal property and the tannins are predominantly responsible for the AA of the grain. Germinative energy (GE), enzymic activity, and total fungal count [TFC], and infection levels of 12 FM grain types of varied phenolic content were measured to determine the impact of phenolics in FM grain on its malt quality. The malt quality of high-phenol FM types was much higher than that of the low-phenol types, with respect to enzymic activity. TFC was negatively correlated with grain total phenolics (TP) and amount of phenolic type (APT) and there were some negative correlations between fungal species infection levels and TP and APT (p<0.05). GE and enzymic activity were positively correlated with TP and APT (p<0.05) and negatively correlated with TFC (p<0.01). The data indicate that phenolics in FM grain impact positively on its malt quality by contributing to its antifungal activity. Cookies in which wheat cake flour was substituted with 15, 35 and 55% (w/w) of either a non-tannin or a high-tannin FM flour were analysed to assess the impact of FM phenolics on cookie quality and AA (health-promoting potential). FM-substituted cookies, particularly those with high levels of the high-tannin FM, were inferior to cake flour cookies (control), with respect to spread, texture and integrity and their dark colour decreased their acceptance by a consumer panel. However, the acceptability of cookies containing up to 35% of either FM type was similar to that of control cookies. Cookies containing the high-tannin FM had antioxidant activities that were similar to or higher than the antioxidant activities of several plant products on the market. Thus, potentially health-promoting cookies can be made by substituting up to approximately 35% wheat with a high-tannin FM. The study indicates that high-phenol FM grain types have good malt quality, which is partly due to the antifungal activity of their phenolics. Although FM phenolics, particularly tannins, seem to affect cookie quality negatively, they contribute significantly to their health-promoting potential. / Thesis (PhD)--University of Pretoria, 2009. / Food Science / unrestricted

Grain is the single most important export commodity shipped through four important Canadian ports on the Pacific Coast. Recent rapid growth in these exports have strained present facilities close to capacity. Therefore the necessity has arisen to study the problem of future requirements for grain handling facilities in British Columbia. Furthermore the over-all development of British Columbia ports has been widely discussed in recent years and because grain is such an important export, the problem of port development requires specific study of grain handling facilities. Investigation of future grain handling requirements relied on both library and field sources. Field work, mainly in the form of interviews with people in port administration and grain handling and selling were especially useful in gaining first-hand knowledge of the actual problems of grain exporting. Facts and opinions gained from field work were also invaluable to interpretation of a large mass of statistics that were available from various library sources. The results of the research have led to several conclusions. The most important is that the Pacific Coast of Canada requires new grain handling facilities in the near future. In addition improvements in handling are possible within existing facilities and throughout the extensive system of grain gathering which begins on the farms, hundreds of miles from the export point. In addition to the above findings there are several important secondary conclusions. First, the markets for grain are likely to continue growing in the foreseeable future. Because the markets of greatest growth are near the Pacific Ocean, Canada's West Coast ports are well situated to serve them. Second, the United States Pacific ports are also well situated to provide direct competition with Canada. If and when this competition becomes more direct, Canada will require the best facilities to keep its customers. Third, Canadian ports have definite advantages to ship operators over the United States ports in the form of lower charges for port use, but maintenance of efficiency in Canadian ports is essential to maintaining this advantage. Finally, the main Canadian Pacific ports are physically suitable for the expansion of grain handling facilities. / Business, Sauder School of / Graduate

The objective of this study is to evaluate the configuration of China's grain production pattern and the implications for agricultural trade. A spatial equilibrium model is developed to optimize grain production and distribution in China and its trade relationship with its trade partners. This study focuses on four grain crops: rice, wheat, com, and soybeans. The model divides China into 31 producing regions and 31 consuming regions. The model also includes seven exporting countries and six Asian importing regions. Results indicate that China can improve its grain production and social welfare through production specialization under a free-trade environment. China could become a major wheat and soybean importer, and a com and rice exporter to Asian countries. The study also provides perspectives on U.S. exports to China and other Asian countries.

An investigation of austenite grain growth of two bearing steel grades; 100Cr6 and100CrMnMoSi8-4-6 is performed. Austenitization treatments were performed between 860°C and 1200 °C for 5 minutes to 5 hours and the grain size was determined for each sample.Grain boundary etching was carried out using a water based, picric-acid etchant. Generally,100CrMnMoSi8-4-6 was harder to etch than 100Cr6. Therefore, a precipitation heattreatment was performed in order to facilitate etching of prior austenite grain boundaries in100CrMnMoSi8-4-6. The precipitation treatment was found to be effective. However, theprecipitation heat treatment was not suitable for 100Cr6 as the grain size increased duringthe precipitation heat treatment.Light optical microscope equipped with a camera was utilized to take micrographs for grainsize evaluation. Jeffries' standard procedure according to ASTM E112-96 was used tomeasure the grain size. The results shows that the austenite grain size increases withtemperature and time as expected. The experimental data was fitted to a well-known graingrowth model. The model only worked for the temperatures investigated and could not bemade to fit different temperatures.Local grain size variation was studied and its influence on fatigue properties was evaluated.The result showed that variation in local grain size can significantly alter the fatigueproperties. The findings are only theoretical and have not been tested practically.Two different spheroidization heat treatments and one homogenization heat treatmentwere performed. Both spheroidization heat treatments investigated exhibited similar grainsize. The homogenization heat treatment reduced the local grain size variation.Homogenization treatment prior to the spheroidization treatments did not increase ordecrease the grain size. The long heating, holding and cooling times in the secondspheroidization heat treatment is probably the reason for the lack of grain refinementcompared to the first spheroidization heat treatment. The grains had time to grow to theinitial austenite grain size during each cycle.

No description available.

Cash grain producers of Virginia’s Northern Neck region face considerable yield and price uncertainty resulting in substantial income risk. This study evaluated several alternative production and marketing strategies in a portfolio analysis using the Target MOTAD framework. The alternative risk management strategies evaluated included hedging using options and futures, cash contracting, and participation in government commodity programs and crop insurance programs. Unlike most previous studies which have treated the decision-making process as a single period process, this study formulates the problem as a recursive two-stage model. The mean forecast deviation approach was used to model activity risk. The results suggest that even though government program participation is the most risk efficient strategy, a great deal of complementarity in risk management exists between the government programs and marketing strategies using commodity futures and options. Crop insurance was found to be ineffective for the representative farm under consideration. / Master of Science