Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is an invasive worldwide pest of many agricultural, horticultural and ornamental crops. They are difficult to control because of their small size and high resistance to chemical insecticides. The aggregation pheromone of this species is currently used for monitoring, but the full potential for use of this and other pheromones has not yet been explored. Two male-specific headspace volatiles have been previously identified: neryl (S)-2-methylbutanoate which acts as an aggregation pheromone and (R)-lavandulyl acetate, for which the role is unclear. The roles of these compounds were studied to understand how they can be used in pest management. Laboratory bioassays showed that the aggregation pheromone, apart from being an attractant, also increased the activity level of adult F. occidentalis. This could be utilized to activate the thrips out of their concealed spaces within the crop and enhance pickup of chemical insecticides. (R)-lavandulyl acetate reduced the walking and take-off activity of adult females but increased the activity level of adult males. The possible role of this compound as a mating pheromone is discussed. The chemical analysis of male-exposed filter paper discs showed the presence of another compound, 7-methyltricosane, which was shown to act as a contact pheromone for species recognition. Adult females respond by raising their abdomen showing mating rejection towards adult males while abdominal wagging sideways was observed in adult males, a behaviour used in aggressive male-male interactions. This is the first identification of a contact pheromone in the order Thysanoptera.

This research is concerned with the dynamic relationship between agricultural advisers, knowledge and soil in England. On the basis that agricultural advisers have always played a central role in linking research and farming practice and implementing policy on the farm, the thesis explores the role of the adviser in facilitating a shift towards sustainable soil management (which encompasses a range of complex and knowledge intensive practices) and to the realisation of policy objectives in this domain. Specifically it aims to provide detailed empirical evidence of the role that agricultural advisers play in the acquisition, utilisation, generation and transfer of knowledge about soil best management practice and to elicit the factors that enable and constrain these knowledge processes. Conceptually, the research draws on approaches to knowledge and knowledge processes in agriculture from the allied disciplines of rural geography, rural sociology and extension science. An actor-oriented Agricultural Knowledge and Information System (AKIS) approach provides the basis for examining adviser interactions with both the research and farming communities. While the AKIS describes the factors that enable and constrain how advisers engage in knowledge processes in terms of connections across institutional interfaces between research, advice and farming, an actororiented approach, which understands knowledge processes as social processes operating across social interfaces, enables exploration of how individual advisers behaving as autonomous agents resolve these constraining and enabling factors. The- study, combining quantitative and qualitative methods, employs an extensive postal questionnaire survey of a 163 agricultural advisers from across England and three detailed case studies where sustainable soil management is a central theme, namely: the Landcare Project; the UK Soil Management Initiative; and the SUNDIAL Fertiliser Recommendation System. The data describe an advisory community with a range of involvement, concerns and competence in soil management. Patterns of acquisition and utilisation of knowledge about soil best management practice revealed by the questionnaire data suggest that advisers are actively seeking and using knowledge about soil management, although some are more constrained than others in accessing it. These patterns, however, only provide a partial understanding of the complex knowledge processes in which advisers engage as they operate at the boundaries between science and practice. As such, qualitative data from the case studies are used to reveal that, in bridging the different institutional cultures and life worlds of research and practice, advisers encounter different understandings and expectations of soil best management practices. Rather than simply acquiring, utilising and transferring knowledge, the data reveal that advisers negotiate, adapt, transform, generate and integrate knowledge about soil as they struggle to reconcile the principles of research-based soil best management practice with the practical and business constraints of the farm. In doing this advisers, and agronomists in particular, tend to closely align themselves with the interests of the farming community and as such are more likely to reject or question soil best management practice. In addition the apparent lack of advisers' competence and skills in certain knowledge intensive soil best management practices and their reliance on experiential knowledge further explains their reluctance to engage in soil best management practices derived from national research. Integration of knowledge through dialogue and understanding emerges as key to overcoming these tensions and providing the basis for facilitating sustainable soil management. Advisers are shown to have a central role in integrating knowledge from research and from farmers. The processes and relationships that enable this integration are identified. The thesis concludes with some policy relevant suggestions to improve the effectiveness of advisers' participation in the transition to sustainable soil management in England. These include: exploiting a diverse and flexible advisory community; improving advisers' skills and expertise; instilling in them confidence to provide credible and practical soil best management practice; and improving the quality of communication between the advisers, researchers and farmers. Future research directions are reviewed in the context of the proposed implementation of Soil Management Plans on all farms in England as a component of cross compliance within CAP reforms.

This thesis explores how, in the wake of momentous agrarian reforms implemented during the 1980s and 1990s, Vietnam succeeded in generating both a strong increase in agricultural growth, and remarkable trends in poverty reduction. Three specific channels of transmission between agricultural growth and rural poverty reduction are explored and evaluated empirically using the Vietnamese Living Standard Survey. Chapter 2 investigates the impact on agricultural investments of the strengthening in tenure security induced by Vietnam's 1993 Land Law, which set up a new land tenure system based on de jure private property rights. Idiosyncratic characteristics of Vietnam's land reform and the panel nature of the VLSS are taken advantage of to capture the exogenous changes in tenure security brought by the 1993 Land Law. By interpreting the results in the light of Vietnam's agrarian history, I shed light on the role of formal institutions during the process of establishing a new private property right system. Chapter 3 explores the role of education in promoting agricultural growth and documents how, in the 1980s, Vietnam emerged from thirty years of war with literacy levels that are normally achieved by middle-income countries. The differential in educational attainment between North and South Vietnam is used to devise an instrumental variable strategy and to evaluate the contribution of Vietnam's high initial education levels to rice yields. The results confirm the importance of literacy and numeracy skills as pre-conditions for agricultural growth but highlight the importance of non-linearities in the impact of schooling, and of factoring in information on the quality in education in order to better understand the processes through which education affects economic efficiency. Finally, Chapter 4 showed that growth in the agricultural sector had been remarkably pro-poor as it benefited even the poorest of the poor, probably because of favourable initial conditions for pro-poor agricultural growth.

Dairy calves in the U.K. are currently reared on ‘least cost’ principles, with minimal milk feeding and early weaning to solid foods. This has been described as maintaining the calf in ‘a state of chronic hunger’. As well as repercussions on calf health, growth and welfare, human studies suggest that underfeeding the newborn is a major risk factor for metabolic disease in the adult. The aims of this study were to determine current dairy calf rearing practices across the U.K., to investigate the performance of Holstein heifer calves fed increased milk replacer (MR) compared to restricted volumes, and to determine the impact of this on key performance indicators (KPIs) of these animals as calves and growing heifers. A postal questionnaire was offered to one thousand U.K. dairy farmers to determine current calf rearing practices. The response rate was 72% and revealed that housing and feeding practices were variable between farms. The majority of farmers (93%) fed restricted volumes of milk or milk replacer to their pre-weaned calves. The body weight, withers and loin height, heart and belly girth, crown to rump length, hock-fetlock length and body condition score (BCS) were recorded weekly from birth to 12 weeks and monthly from 12 weeks until conception in two groups of Holstein heifer calves on one commercial dairy farm in the north-west of England, U.K. Calves were assigned to a restricted, Group R (n = 50) or ad libitum, Group A (n = 50) MR feeding strategy from birth until weaning. Growth rates were greater for Group A (0.72kg/day) from birth until 3 weeks than Group R (0.17kg/day). Body condition score increased for Group A during this period (0.1 points) while it decreased for Group R (0.3 points). Thereafter, growth rates were similar between dietary groups although no catch-up growth was observed for Group R animals. Changes in morphometric measures were greater for Group A calves than Group R from birth to 12 weeks. From 12 weeks of age onwards, dietary group differences in morphometric measures disappeared but body weight differences remained until conception. The glucose metabolism and insulin sensitivity of a subset of heifer calves (n = 6 Group A, n = 6 Group R) was investigated at 3, 12 and 39 weeks of age and was shown not to be affected by dietary group. The carcass composition of Holstein bull calves assigned to one of the two dietary groups was assessed. Calves were studied at birth (n = 3), 3 weeks, 9 weeks or 12 weeks (n = 3 per dietary group at each age). Carcass composition was assessed using spiral CT technologies. Group A calves had greater internal adipose deposition at all ages but there was no difference in carcass associated adipose tissue. The age at puberty, first service and conception was between 2 and 3 weeks lower for Group A animals than for Group R. Increased MR feeding of Holstein heifers allows for greater growth rates and earlier entry into the milking herd.

The legume podborer, Maruca vitrata (Lepidoptera: Crambidae) is a serious pest of legumes throughout Asia and Africa. Previous workers identified (E,E)-10,12-hexadecadienal (EE10,12-6:Ald), (E,E)-10,12-hexadecadienol (EE10,12-16:OH) and (E)-10-hexadecenal (E10-16:Ald) as sex pheromone components of female M. vitrata. They developed a lure that attracts male moths in the field in Benin but they failed to attract male moths in the laboratory, or to develop a lure that attracts male moths in Asia or the rest of Africa. Synthetic lures also attracted significant number of female moths. The objectives of this study were to re-examine the sex pheromone of female M. vitrata with the aim of developing synthetic lures that attracted male moths in a wind-tunnel and in the field in both Africa and Asia and determining the reason for attraction of female moths to synthetic pheromone lure. Procedures were developed for mass rearing M. vitrata of African and Indian strains using synthetic diet without loss of vigour and reproductive potential. The female sex pheromone was re-examined using gas chromatography linked to mass spectrometry (GC-MS) and gas chromatography coupled with electroantennography (GC-EAG). In this study two new components, (E)-10-hexadecenol E10-16:OH and (Z,Z,Z,Z,Z)-3,6,9,12,15-tricosapentaene (ZZZZZ3,6,9,12,15-23:H), were identified as a part of the M. vitrata pheromone blend along with (E,E)-10,12-hexadecadienol (EE10,12-16:Ald). Laboratory windtunnel tests showed attraction of male moths to EE10,12-16:Ald and blends with E10-16:OH or ZZZZZ3,6,9,12,15-23:H equal to that of natural female extract for the first time. Field trials were conducted in West Africa in Burkina Faso, Ghana, Nigeria, Benin and at two locations in India. Although variable trapping results were obtained, in Burkina Faso the major component, EE10,12-16:Ald alone, caught significantly more moths than other synthetic blends consisting major and minor components. A similar result was found in India and the trap catch was significantly increased when E10-16:OH was added to the major component in a ratio of 10:90. Synthetic blends also captured female moths in West Africa but not in India. The role of the newly identified pheromone components and possible reasons for the female moth capture are discussed.

Master of Agribusiness / Department of Agricultural Economics / Michael Boland / The Western Sugar Cooperative is a 135,000 acre sugar beet processing cooperative headquartered in Denver, Colorado with sugar beet processing factories located in Ft. Morgan CO, Torrington WY, Scottsbluff NE, Lovell WY, and Billings MT. The objective of the thesis is to analyze alternatives for maximizing the net revenue of co-products at Western Sugar. The ethanol policies of the U.S. government have had many unintended consequences including increasing the price of corn which is a key ingredient in animal feed production. Sugar beet co-products are produced in fixed proportions. That is, for every unit of sugar produced a corresponding unit of sugar beet pulp is created which is mostly water. Historically this has been dried into an animal feed pellets, however removing water from any high volume and high speed manufacturing process is energy intensive. Natural gas prices have increased dramatically and are projected to stay that way for a long time. As a result, the cost of manufacturing pellets is very high. The research shows that we are able to significantly increase our net income by increasing the percentage and price of pressed feed pulp rather than drying the pulp into pellets. This equals 20 million dollars of revenue in our pulp product line for the 2008-2009 sugar beet campaign. The thesis contains various analyses for changes in critical costs and prices. More importantly it details the subsequent management decisions implemented to maximize net income in the co-products business.

Master of Science / Department of Grain Science and Industry / Sajid Alavi / Extrusion is a popular technology for production of expanded products. However, variability in multiple input parameters can lead to significant variations in the end product which becomes a concern for process control and efficiency in industries. This study was focused on understanding the uncertainty in input parameters during extrusion and their impact on variability in output. A mechanistic model was developed for bubble growth dynamics in starch based melts at microscopic and macroscopic levels using heat, mass and momentum transfer equations. This model was used for uncertainty simulations using the Monte-Carlo method by integrating it with a stochastic interface for input of randomly generated process data based on experimentally obtained distributions and output of simulated distributions of end-product properties such as expansion ratio (ER). A pilot-scale twin screw extruder was used for processing of corn-based expanded products, which was used as a model system for experimental validation of the mathematical model. A 4x2 factorial design was used with different in-barrel moisture contents (19, 23, 28 and 33% dry basis) and extruder screw speeds (250 and 350 rpm) to measure process data (such as moisture injection rate and T[subscript]d[subscript]i[subscript]e) and product characteristics (such as ER). Average experimental ER ranged from 2.33-10.88 and simulated ER ranged from 1.16-12.86, where both had similar trends with respect to in-barrel moisture (MC) and die temperature (T[subscript]d[subscript]i[subscript]e = 108.8-145.4˚C) although conditions for optimum expansion differed possibly due to non-correspondence of material properties. Experimental coefficient of variation (CV) for MC (0.6-1.6%) and T[subscript]d[subscript]i[subscript]e (0.29-0.91%) and an assumed CV of 2% for a material constant (k[subscript]f) that controls the consistency index of starch-based melt were used for simulations. The stochastic model was used to carry out sensitivity analysis for CV of ER with respect to CV of MC, T[subscript]d[subscript]i[subscript]e and k[subscript]f. Variability in ER was impacted the most by variation in T[subscript]d[subscript]i[subscript]e, followed by MC with k[subscript]f having relatively lower impact on it. Since there are fundamental flaws in modeling approach as reflected by the thermodynamically infeasible parameter dynamics, the results from these mechanistic or stochastic simulations cannot be used as a basis for scientific analysis.

Master of Science / Department of Grain Science & Industry / Yong-Cheng Shi / The objective of this study was to systematically understand the changes of rice during the parboiling process. Isolated rice starch, milled rice and paddy rice kernels of the same variety (18% amylose) were examined after steeping at temperatures (60-75 oC) below and above the onset of rice starch gelatinization temperature for different durations in 66.7% water. Changes in gelatinization temperatures were greater for isolated starch ˃> milled rice ˃ paddy rice. Annealing above samples’ original To caused partial gelatinization, loss of crystallinity, and birefringence as determined by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and light microscopy. However, starch granules in milled rice and paddy rice, which were surrounded by non-starch components, maintained their granule integrity. Scanning electron microscopy (SEM) revealed morphological differences between starch granules within native and steeped rice kernels. Steeped kernels had denser structures than native kernels, as determined by high resolution X-ray microtomography. Rice starch granules and kernel characteristics were altered significantly during steeping and changes in isolated starch differed from those inside the rice kernels. To study the changes during the steaming process, the morphology of the rice kernel and starch granules within the kernel were examined immediately after heating at110oC for 20 min. Starch was completely gelatinized as determined by DSC and XRD, indicating the disruption of all short-range crystallinity of starch in parboiled rice. However, SEM showed intact starch granules and light microscopic images showed starch granules embedded in the rice kernel. Interestingly, these granules displayed Maltese cross patterns. For the first time, we demonstrated that starch granules were birefringent and showed the Maltese cross but were not crystalline.

Master of Science / Department of Grain Science and Industry / Yong-Cheng Shi / Jon M. Faubion / One long-term goal of cereal science research is to increase the shelf life of baked products and one approach to that goal has been the use of emulsifiers. Emulsifiers are surface-active agents, some of which improve specific properties of baked products. Two emulsifiers, sodium stearoyl lactylate (SSL) and oleyl lactylic acid (OLA) are similar in structure, the difference being the acid moiety: stearic versus oleic acid. Widely researched, SSL has found many uses in baked products. However, how OLA interacts with starch/flour in baked products or how that interaction affects product quality is not well understood. The objective of this study was to understand the interactions between normal wheat starch and these emulsifiers, as well as the differences between SSL and OLA in those regards. The effects of the two emulsifiers on the pasting properties of wheat starch and wheat flour were determined using a MicroViscoAmylograph. Heating at 6oC/min with increased emulsifier concentration (0-2%) resulted in increased hot paste viscosity and apparent interaction of both emulsifiers with wheat starch. Solid content affected both maximum hot and final viscosity. OLA produced increased maximum hot and final viscosities with increased starch concentration and emulsifier concentrations. For wheat flour, higher concentrations of SSL reduced both maximum hot paste and final viscosities. OLA behaves differently with wheat flour. At lower flour concentrations, higher concentrations of OLA reduced maximum hot viscosity. The effects of SSL on starch were affected by an increased heating and cooling rate (10oC/min). Heating stage microscopic analysis revealed that the presence of emulsifiers inhibited granular swelling beyond the normal gelatinization temperature (65oC) in both starch and flour systems. OLA’s effect in this respect was greater than that of SSL. Complex formation between emulsifiers and wheat starch and wheat flour was determined using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). For isolated wheat starch and hard wheat flour, DSC and XRD indicated that OLA complexes to a greater extent than does SSL. For flour, XRD indicated no difference exhibited in the interaction of the emulsifiers with the flours. KEYWORDS: Emulsifiers, Starch, Wheat flour

Morpho-physiological characterization and whole genome transcript profiling of rice genotypes that belongs to sub-species Indica, Japonica and wild relatives were carried out under salt stress. The existence of qualitatively different mechanisms of salt tolerance across the genotypes was identified. Multivariate analysis was applied to categorize the genotypes according to their level of tolerance. Modified SAM analysis elucidated the trait specific expression of genome wide transcripts. Gene ontology enrichment analysis identified the genes involved in different molecular functions such as signal transduction, transcription factor and ion homeostasis etc. Gene network analysis identified the regulatory network of genes that are active in different tissues. The differential expression of transcripts of four tolerant and two susceptible Indica genotypes under stress were further analysed. The candidate genes for different biological processes and molecular functions are identified and discussed. Highly induced stimulus responsive gene Os01g0159600 (OsLEA1a) and Os05g0382200 (Nhx) can be mentioned for instance. The differentially expressed genes that are located within the salt stress related QTLs were also identified. The transcriptomics data were also used to predict the salinity tolerance of genotypes using OSC-PLSDA model. The combined physiological and transcriptomic approach of this study gives a complementary whole organism assessment of plants responses to salt stress.