Master of Science / Department of Grain Science and Industry / Sajid Alavi / There is a renewed focus on biodegradable polymers in packaging applications due to environmental concerns associated with conventional plastics. Melt extrusion was used to synthesize nanocomposites from poly (lactic acid) (PLA) or poly (butylene succinate) (PBS) blended with natural nanofillers — chitin whiskers (CHW, 1-5%), nanocrystalline cellulose (NCC, 1-5%) or lignin-coated nanocrystalline cellulose (LNCC, 3%). Transmission electron microscopy and x-ray diffraction indicated that the natural nanofillers were uniformly dispersed in the polymer matrix. For PLA based nanocomposites, differential scanning calorimetry showed a decrease in change of heat capacity at glass transition (ΔCp) with increased nanofiller addition, indicating greater confinement of polymer chains. For PBS based nanocomposites, nanofillers acted as nucleating agents and promoted recrystallization of polymer as reflected in increase of degree of crystallinity (Xc) from 65.9-66.8 to 75.6%. By addition of NCC and CHW, tensile strength (TS) of PLA based films increased from 50.2 MPa to 70.9 MPa and 52.1 MPa, respectively, while TS of PBS increased from 23.2-24.9 MPa to 32.9 MPa and 43.6 MPa, respectively. Elongation at break (E%) of nanocomposite films ranged from 9.1 to 15.3, and in general decreased with addition of nanofillers. LNCC did not significantly improve mechanical properties of PBS and PLA films. Additionally, 3% NCC addition reduced oxygen transmission rate (OTR) of PLA from 209.9 to 180.8 cc/m[superscript]2/day, which further reduced to 109.3 cc/m[superscript]2/day by adding compatibilizer methylene diphenyl diisocyanate (MDI, 4%). Water vapor transmission rate (WVTR) of PLA also reduced from 44.4 to 28.6 g/m[superscript]2/day with 3% NCC and 4% MDI addition. Similarly OTR and WVTR of PBS decreased from 737.7 to 280 cc/m[superscript]2/day and 83.8 to 49.4 g/m[superscript]2/day, respectively with 3% NCC. Use of 4% MDI further reduced OTR and WVTR to 23.8 cc/m[superscript]2/day and 30.8 g/m[superscript]2/day, respectively. Use of starch can potentially reduce the costs of bio-based nanocomposites films. Up to 40% starch was incorporated during synthesis of PLA and NCC nanocomposites using solution mixing method. Addition of starch decreased TS from 35.8 MPa to 18.4 MPa and E% from 8.3% to 6.0%. Use of NCC (1%) and MDI (4%) improved the mechanical properties to a certain extent.

Master of Agribusiness / Department of Agricultural Economics / Allen Featherstone / For the past 25 years, Free Trade Agreements (FTA) in Asia have been increasing. This allows for a potential expansion of exports into Asia for a variety of goods. However usually these agreements have not covered agricultural products. The most recent multilateral agreement currently includes agricultural products and agricultural trade. U.S. pork exports have been on the rise with Asian countries. Trade openness with Asian countries allows U.S. pork companies to gain a market in the region. This thesis estimates the economic impact that FTA’s and multilateral agreements have on pork exports, through the level of open markets measured by Freedom House. Using regression analysis, this research examines the determinants to U.S. pork exports, where trade openness is a major independent variable. Pork is a popular meat preference in East Asia. A regression analysis was estimated to determine the shift along the demand curve of U.S. pork exports to three East Asian countries, China, Japan, and South Korea. Overall all three countries showed their trade openness being weakly associated with the U.S. pork export demand to that particular country during the years of 1995–2013.

Master of Science / Department of Agricultural Economics / Timothy J. Dalton / In Kenya, agriculture governs the country’s fiscal economy, and this reliance on agriculture can cause both economic and hunger problems, a result of the country’s dependence upon rainfall for agricultural production. Kenyans must find ways to combat severe drought conditions; this can be accomplished through the adoption of inputs that decrease the probability of crop failure. The objective of this research is to determine whether variability exists in Kenyan maize yields, and whether or not specific inputs, specifically hybrid varieties, are either variance/skewness increasing or decreasing. The data used for this study was collected from a survey, designed by Egerton University’s Tegemeo Institute of Agricultural Policy and Development and Michigan State University, and administered in Kenya in the following years: 1997, 2000, 2004, and 2007. The survey identified factors of crop and field level production, such as inputs, crop mix, marketing data, and demographic information. This research makes use of only the 2007 data, comprising 1,397 households in total. The objectives of this thesis aim to go beyond the scope of typical production function regressions where yield is a function of a set of inputs, by examining further moments of yield, variance, and skewness to determine whether variability exists in Kenyan maize yields. Results indicate that variability does exist within Kenyan maize yields, often a result of differing input levels among households. In terms of overall impact of each variable on mean, variance, and skewness of maize yields, seed quantity, nitrogen use, and hybrid seed contribute the most to influencing these factors. In contrast, years of experience with hybrid maize, land tenure, terraced land and labor have the least influence on mean, variance and skewness within this research. Results also bring to light the popular debate against hybrid varieties versus open pollinated (OPV) or traditional varieties, and identify hybrid varieties as a source of variability in mean, variance and skewness of yields. Hybrid varieties should be paired with the knowledge of how to maximize yield in conjunction with other inputs, to give Kenya the opportunity to see substantial productivity gains throughout the country, especially in arid and semi-arid regions.

Master of Agribusiness / Department of Agricultural Economics / Arlo Biere / In the world of fast paced competition with a focus on profits, small businesses are always looking for ways to stay ahead of their competition. One way to maintain the competitive advantage is to join forces with another small business that sells and services similar products. Mergers and acquisitions have been very common in agribusiness since the farm economy collapse in the early 1980s. Farms have been increasing in size, equipment has been growing in complexity with new technologies and size to keep up with growing farm size and equipment manufacturers are merging to create larger corporations that offer more solutions to the end user. Additionally, fewer machines are being purchased by growers and producers each year and the machines that are being purchased are able to do more than previous models. The new complexities require highly trained and skilled technicians to make repairs and service these machines. Farming practices continue to evolve with more limited- and no-till crop production. These factors are contributing to dealers forming larger multi-store operations with trade areas large enough to provide an adequate return on investment to attract the resources required to sell and support technologically advanced agricultural equipment. Large multi-store organizations support the requirement of customers by providing higher levels of customer service. As these large organizations increase in size they ensure a more sustainable business model with reduced fixed expenses leading to higher returns on sales and increased total sales. This study will examine two multi-store farm equipment farm equipment dealerships with a total of a total of eleven locations and make recommendations to create a merger of equals. The analysis will include a review of current sales data at each location and make recommendations for any new locations strategy using industry data as well. This information will help determine which locations should be eliminated or combined into single locations to reduce expenses. The study will also provide data to support implementing standard job pricing in the new organization. A new functional management structure will also be recommended to guide the new company towards increased sales revenues and position the organization for long term growth and sustainability.

Doctor of Philosophy / Department of Grain Science and Industry / Yong-Cheng Shi and Jeff D. Wilson / Sorghum (Sorghum bicolor [L.] Moench) is the fifth most important cereal grain grown in the world. Sorghum is an important cereal crop for both animal feed and biofuel production in the United States. The genetic, environmental, and agronomic management influences on sorghum starch and protein chemistry and functionality were evaluated. A method was developed to determine amylose content in cereal starches that achieved the same level of accuracy and precision as traditional methods, but had the capability of analyzing 50 samples per day or approximately a 10-fold increase in throughput. The effect of kernel maturity on sorghum starch properties was conducted by collecting grain from two hybrids at various stages throughout kernel development. The samples ranged from 16.3% amylose in 10 days after anthesis (DAA) to 23.3% amylose in 35 DAA. Starch thermal properties were also altered due to DAA, most notably the ΔH was 16.1 J/g at 14 DAA and 9.45 J/g at 56 DAA. In a separate study using the same developmental samples the protein and starch digestibility was analyzed. The kernel maturity had a notable effect on digestibility with the maximum digestibility occurring at 17 DAA with 82.44% digestible protein. In another study a diverse set of 19 sorghums was grown in three locations in Kansas to evaluate the genetic, location, and genetic x location effect on grain quality attributes. The physical and chemical properties of the sorghums were greatly affected by the genotype, environment, and the GxE interaction. Protein content ranged from 11.09% to 15.17% and digestibility ranged from 45.58% to 62.05% due to genotype. The final study investigates the role of agronomic management on sorghum grain quality. A sorghum hybrid was grown on plots with varying nitrogen fertilization rates and cover cropping systems that are currently used by Kansas producers. Grain attributes such as hardness and size were variable due to the treatments but negative impacts to protein digestibility were not seen due to cropping system. Sorghum grain quality is affected by many variables and a better understanding of the variables will lead to a higher quality product.

Master of Science / Department of Grain Science and Industry / Bhadriraju Subramanyam / Heat treatment of grain-processing facilities involves using elevated temperatures of 50- 60˚C for 24 h or less to manage stored-product insects. Heat is an alternative to a non-ozone depleting fumigant sulfuryl fluoride, which was registered in the United States in 2004 for disinfestation of grain-processing facilities. In this study, life history traits of the warehouse beetle, Trogoderma variabile Ballion, were characterized on ground cat food at 28°C and 65% RH to facilitate harvesting life stages of a specific age for bioassays with heat. Eggs laid by females were observed for daily eclosion. Eggs hatched on days 6 through 10, and the mean proportion for egg hatching was 87%. Larvae hatching from eggs (first instars) were reared on ground cat food and their head capsule widths were measured every 2 d until all larvae became pupae. Head capsule widths indicated six instars and the total larval duration ranged from 28-40 d. Pupae became adults in 3-9 d. Newly eclosed unmated female adults lived 7 d longer than unmated males (16 d), whereas mated males lived 2 d longer than mated females (8 d). Eggs were not observed when food was not provided to male and female pairs. Females started laying eggs 2 d after pairing until the fifth day. The total number of eggs laid by mating pairs in the presence of food ranged from 30 to 135. Exposure of eggs, young larvae, old larvae, pupae, and adults of T. variabile at 46, 50, and 54°C and 15-20% RH for four fixed time periods showed pupae to be generally more heat tolerant than other life stages. At 46, 50, and 54°C, complete mortality of all stages occurred at 1440, 120, and 30 min, respectively. Pupae also were generally more heat tolerant than other life stages during tests in pilot flour and feed mills at Kansas State University and in a commercial grain-processing facility. However, results from pilot and commercial mills were not as conclusive as the results at fixed temperatures in the laboratory.

Master of Science / Department of Agronomy / J. Anita Dille / Kraig Roozeboom / Increasing numbers of herbicide-resistant weed species require alternative methods of weed suppression to be examined. This study quantified the interaction between various cover crop or herbicide systems and horseweed [Conyza canadensis (L.)] growth. Fall cover crops of winter wheat [Triticum aestivum (L.)], winter rye [Secale cereal (L.)], barley [Hordeum vulgare (L.)] and annual ryegrass [Lolium multiflorum (L.)] were seeded in November 2012 and 2013. Spring cover crop of oat [Avena sativa (L.)] was seeded in April 2013 or rye was seeded in March 2014. All cover crops were no-till seeded into grain sorghum stubble [Sorghum bicolor (L.) Moench]. Four herbicide treatments were fall or spring applied, with and without residual. The spring non-residual treatment was also applied to plots of winter rye. Cover crop plots were split and terminated with a roller crimper or glyphosate application prior to soybean [Glycine max (L.) Merr.] planting to determine the effect of termination method on treatment performance. Soybean was planted in June 2013 and May 2014 and mechanically harvested in October of both years. Horseweed density, biomass accumulation, and soybean yield data were quantified. Horseweed height, whole plant seed production, and seed subsamples were recorded in the untreated fallow control, winter wheat, and winter rye plots in 2014. Horseweed suppression by winter rye approached 90%, levels similar to suppression by herbicide systems. In both years, herbicide plots had less than half the horseweed biomass than any of the cover crop systems. In 2013, soybean yields in herbicide plots were at least 1,500 kg ha[superscript]-1, nearly more than double yields in cover crop plots. Soybean yields in 2014 were more consistent across treatments; barley and spring rye plots achieved yields equal to or greater than 2,000 kg ha[superscript]-1. Winter rye and winter wheat reduced horseweed seed production by 60% compared to the untreated fallow control, with no effect on individual seed weight. Seed production varied across plants, with the untreated control producing the greatest number of seeds. Cover crops were successful at reducing horseweed biomass, suppressing horseweed pressure, preserving soybean biomass, and protecting soybean yields when compared to a fallow untreated control.

Master of Science / Department of Agricultural Economics / Michael R. Langemeier / This thesis will determine if economies of size are present in production agriculture or the farming sector and if convergence or divergence is occurring. Change in the farming sector was analyzed using five-year moving averages from 1973 to 2007. Six key variables were analyzed; value of farm production, total acres, economic total expense ratio, operating profit margin ratio, asset turnover ratio, and percent of livestock income. Data from the Kansas Farm Management Association were used in this study. To be included in the study, a farm had to have five years of continuous, usable data for a five-year period between 1973 and 2007. Moving five-year averages were calculated for the farms that met this qualification. Data were sorted by value of farm production and broken down by quartiles and deciles. Trend regressions were used to calculate growth rates of the key variables and the difference between the top and bottom quartiles of the variables. Results suggested that acreage per farm is increasing, farms are doing better at covering their total economic costs, profit margin per farm has decreased, farms are utilizing their assets better, and the percent of livestock income per farm has decreased. When regressing the difference between the top and bottom quartiles to determine growth rates, it was evident that the gaps between the top and bottom quartiles of five of the six variables have widened. The differences in the percent of livestock income between farm quartiles and deciles were not significant. Convergence analysis confirmed the results of the trend regressions and suggested that divergence is evident in the Kansas farming sector. Graphical representation supports the findings of this thesis.

Master of Science / Department of Agricultural Economics / Andrew P. Barkley / The objective of this thesis is to determine the factors that impact the location of organic food production and organic food consumption. The models used test to see if organic foods are consumed where they are produced, the characteristics of consumers which influence their organic consumption, and if organic production is located in the same areas as conventional production. The results of this study showed that organic production is not dependent on conventional production. Education was found to be positively correlated to organic production and consumption while income actually had an opposite effect. Organic production and consumption were also linked to the political liberalness of a state. It was found that urban populations had a negative impact on organic production and Whole Foods stores had a positive effect.

Master of Agribusiness / Department of Agricultural Economics / Andrew P. Barkley / The primary purpose of this research was to identify and quantify the determinants of the number of minority farms in the Southern region of the United States during the time period, 1969-1997. A second objective was to determine the impact of globalization and international trade agreements on the number of African-American farmers in the Southern region of the United States. Regression results indicate that minority farm labor was responsive to the returns to agriculture labor relative to nonfarm labor returns, as well as to cotton and rice prices. Increase in the cotton price increased minority farmer income, slowing the rate of agricultural migration from the Southern region of the United States. To the extent that globalization results in lower cotton prices, international agricultural trade agreements are likely to result in further movement of minority farmers out of agriculture in the Southern region of the United States.