Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Cary L. Rivard / Grafting with inter-specific hybrid rootstock is effective for tomato (Solanum lycopersicum) growers looking to reduce soilborne disease organically and increase fruit yield in the Southeastern US. However, production with grafted tomatoes has not been tested in the Great Plains region of the US. Small-acreage growers would like to produce grafted plants themselves, but many have difficulty with propagation due to water stress in the scion post-grafting and/or high temperatures within healing chambers. Growers may be able to reduce water stress post-grafting by removing the upper portion of the shoot to reduce leaf surface area, but no data exist on the potential effects of this practice on mature plant yield. Five high tunnel and one open-field study were conducted in 2011 and 2012 to investigate yield effects related to the use of two rootstocks and shoot removal during the grafting procedure. Grafting significantly increased fruit yield in five of the six trials (P<0.05). The average yield increases by Maxifort and ‘Trooper Lite’ rootstocks were 53% and 51%, respectively, across all trials. In some trials shoot removal during the grafting process reduced yield and could depend upon rootstock vigor. Another series of experiments were performed testing the efficacy of shoot removal for graft survival during the healing period prior to field planting. Five healing chambers designs were evaluated, and no significant effects of treatment design were observed upon grafted seedling survival. Plants grafted with no chamber had success rates of 81% to 91%. Additionally, three grafting leaf removal techniques were studied, and a partial leaf removal method had significantly higher success rates as compared to fully foliated and defoliated plants (P<0.05). Partial leaf removal may be recommended as a way to reduce water stress in the plant, and could potentially be a way to simplify the grafting process for small-scale producers.

Master of Science / Department of Entomology / C. Michael Smith / The Dectes stem borer, Dectes texanus LeConte, is a pest of soybean, Glycine max (L.) Merrill, in North America. Larval feeding weakens plant stems, triggering lodging of the infested plants and causing significant yield losses. D. texanus infestations in soybean fields are increasing across Kansas and other states, necessitating the development of effective tactics to control this pest. The use of D. texanus -resistant soybean cultivars is a desirable strategy to control this pest since cultural and chemical control options are lacking. In previous studies, the soybean plant introduction PI165673 was identified to be resistant to D. texanus. The objective of this research was to determine the inheritance of resistance to D. texanus in PI165673. F[subscript]2 progeny plants from crosses between the D. texanus susceptible genotypes KS5004N and K07-1544, and the resistant genotype PI165673 were tested in the field for resistance to D. texanus in 2011. Seeds from the cross K07-1544/PI165673 were advanced to the F[subscript]3 generation, and F[subscript]2:3 families were tested in the field for resistance to D. texanus in 2012. At 20 d after infestation with adults, the numbers of oviposition punctures and larvae on each plant were counted to estimate the oviposition puncture per larvae resistance ratio. Segregation for resistance to D. texanus and heritability estimates in the F[subscript]2 and F[subscript]2:3 populations indicated that resistance is controlled by more than one gene. Thirteen F[subscript]2:3 families had a higher (more resistant) resistance ratio than the susceptible parent K07-1544. Mean head capsule widths of larvae collected from K07-1544 and PI165673 plants in 2012 were similar, as was the percentage of larvae per larval instar. According to heritability estimates for each phenotypic trait, progress in breeding for D. texanus resistance using PI165673 will benefit from marker assisted selection. Identification of additional sources of D. texanus resistance besides that in PI165673 is needed to slow larval growth in the stem.

Doctor of Philosophy / Department of Biochemistry / Gerald R. Reeck / Prolamins are the alcohol soluble storage proteins found in the endosperm of seeds from cereals and related grasses. The physical and biochemical properties of prolamins vary between species; and due to their relative abundance can greatly affect the properties and healthfulness of foods from those sources. In this work I investigate peptides from the high molecular weight glutenin of wheat, which is linked to dough elasticity and finished product quality. Using 2D NMR I determined the three-dimensional structure for the repeat peptide Ac- GQQPGQG-Am, which makes up ~50% of the 700 residue central domain. The structure was found to be a flexible β-hairpin with a type II β-turn across residues QPGQ. The NMR structure was later compared to 33 proteins with known three-dimensional structure carrying the exact sequence (backbone RMSD=0.802Å). This finding provides useful insight into the structure of high molecular weight glutenin and the molecular nature gluten elasticity. Alternatively, I studied the kafirin storage prolamins from sorghum, which do not have important physical properties, but are poorly digestible by humans and livestock. Improving digestibility of sorghum could significantly impact human health and nutrition in countries where sorghum is a dietary staple. In this work I devised a unique protocol to isolate kafirins under both non-reducing and reducing conditions. I studied kafirin extracts using SDS-PAGE, HPLC and MALDI-TOF MS, then purified β-kafirin, for the first ever characterization of this single protein. Past studies implicate β-kafirin as a source of poor digestibility due to extensive intermolecular disulfide cross-linking. Contrary to this claim I found more than 50% of β-kafirin was extractable without reducing agents. I used chymotrypsin to digest pure β-kafirin and map 10 cysteine residues to 5 intra-molecular disulfide bonds. Precise pairings have yet to be determined although the protein is largely intact after 12 hours of digestion. This work challenges us to think about sorghum protein body formation and the mechanism that leads to disulfide cross-linking during seed desiccation at maturity.

Master of Agribusiness / Department of Agricultural Economics / Mykel Taylor / The agricultural commodity market has been experiencing previously unseen high prices in recent years. This new era of prices brings with it new challenges within agriculture for farmers and grain buyers within agriculture. This research explores the basis values of hard red winter wheat in Kansas and the elevator characteristics that provide a competitive advantage for elevators buying wheat in Kansas. This research explores hard red winter wheat basis values from elevators located around Kansas from 2002 to 2013. Two hundred twenty eight locations from around Kansas were used in the research. These locations provided the price data that was used for this research. The elevator characteristics used in the research were collected from the Kansas Grain and Feed Directory and the Burlington Northern-Santa Fe and Union Pacific railway companies. Five elevator characteristics were researched that may have a significant impact on an elevators basis. These characteristics are thought to provide a competitive advantage to the location in the form of stronger or narrower basis bids to the farmer, giving the farmer a higher price for his grain. The characteristics researched included elevator capacity, transportation capabilities, elevator terminal status, shuttle loading status, and cooperative or investor-owned business structure. Each characteristic was compared against their counterpart. For example, a location is either a shuttle loader or it is not. The research provides grain companies and farmers some data that they may find useful in marketing grain and setting basis levels in the ever changing and volatile market place in today’s grain industry.

Doctor of Philosophy / Department of Animal Sciences and Industry / R. Scott Beyer / Broiler chicken feed is processed. Cereal grains are ground to reduce particle size and the feed usually is pelleted. When pelleted, broiler diets are steam conditioned and forced through a die causing varying levels of starch gelatinization. Cereal grain particle size and starch gelatinization can be controlled during feed manufacturing. Earlier research has shown that starch gelatinization negatively affects growth performance of 0 to 21 d of age. An experiment was conducted to determine the effects of corn particle size and starch gelatinization on growth performance, dressing percentage, and gizzard size when fed to 22 to 42 d of age broilers. Increasing particle size from 470 to 1240 μm increased body weight gain, dressing percentage, and relative gizzard size. Starch gelatinization increased relative gizzard size. No interaction effects were detected. To expand on previous experiments, a trial was conducted to investigate the effect of starch gelatinization on broiler chick gastrointestinal pH, glucose absorption, and glucoregulation. Starch gelatinization level affected jejunum pH, with a higher pH reported at 20% starch gelatinization. Increases in starch gelatinization decreased blood glucose and increased glucagon level. Highest measured glucagon level was reported in broiler chicks fed the diet with 20% starch gelatinization level diet after 6 hours of starvation. A third experiment was conducted to determine the effect of starch gelatinization on metabolizable energy and amino acid digestibility. Increasing starch gelatinization from 0 to 100% increased true metabolizable energy and fecal output in roosters. No effect was found on apparent metabolizable energy or amino acid digestibility, with an increase in starch gelatinization from 0 to 20%. Increasing particle size from 470 to 1240 μm had a positive effect on 22 to 42 d growth performance. A starch gelatinization level of 20% or lower had no effect on metabolizable energy or amino acid digestion. Older broilers with larger gastrointestinal tracts are unaffected by 20% gelatinized starch; whereas, 20% gelatinized starch reduced blood glucose and increased glucagon levels of young broilers. Lower blood glucose and increased glucagon are indicative of lower glucose storage, and could cause reduced young broiler growth performance when fed diets with gelatinized starch.

Master of Agribusiness / Department of Agricultural Economics / Mykel Taylor / Agriculture subsidization policies have a long history and have been criticized, reformed and heavily discussed multiple times over the last centuries. However, most countries in the world use farm subsidies as a policy instrument and spend billions every year. Especially highly developed and wealthy countries seem to have a tendency to subsidize production agriculture and the agricultural industry. The objective of this thesis is to improve understanding of the impact direct payments or subsidies may have on farm land values via farmers paying higher dollars for ground they rent and capitalization of those higher rents. Analysis is done by comparing the allocation of subsidy dollars from the Common Agricultural Policy on two wheat farms in Germany and Czech Republic, which are member countries of the European Union, to wheat farms in the United States and Australia, countries with relatively lower subsidy levels. Data for the farms include their cost structures, total revenues, and total direct payments. Comparisons of their relative land values and rental rates paid will provide evidence to test the hypothesis that direct subsidies are likely to increase land values. Based on the economic costs of production for the farms in Germany and Czech Republic, the value of land is not necessarily the residual claimant for the direct payments paid out through Europe’s Common Agricultural Policy. Possible explanations for this include restrictions on farmland use and farmland ownership structures held over in former communist countries where farms were owned by the state. These factors are likely to affect potential farmland owners’ perceptions of property rights and their willingness to pay a full market value for land.

Master of Agribusiness / Department of Agricultural Economics / Sean Fox / The commodity markets have seen a great deal of volatility over the past decade, which, for those involved, has created many challenges and opportunities. Some of those challenges and opportunities are related to the behavior of the basis – the difference between the local cash price of grain and its price in the futures market. This thesis examines factors impacting basis for corn and soybeans at an Illinois River barge terminal, inland grain terminals in central Illinois, and in the Decatur processing market. Factors used to explain basis behavior include the price level of futures markets, the price spread in the futures market, transportation cost, local demand conditions, and seasonal patterns. Using weekly data on basis from 2000 to 2013, regression models indicate that nearby corn futures, futures spread, inverted market, days until expiration, heating oil futures, and some months are significant drivers of corn basis. For inland terminals and processor regression models nearby corn futures do not appear to have significant effects. Using the same parameters for soybean basis nearby soybean futures, futures spread, inverted market, heating oil and some months are significant drivers but days until expiration do not appear to have a significant effect.

Master of Science / Department of Grain Science and Industry / Rebecca Miller / Wheat flour tortillas are the second most consumed bread product after white pan bread. Commercial tortillas are formulated with highly viscoelastic hard wheat flours selected and grown for breadmaking. However, the inherent properties of bread flours require costly formula adjustments to enhance dough extensibility necessary for tortilla production. The objective of this study was to identify the biochemical and physical factors in wheat affecting wheat tortilla quality. Six popular hard winter wheat cultivars (1863, Armour, Clara CL, Denali, Everest, Tiger) were grown in five locations in Kansas. Wheat and flour properties were characterized using approved AACCI methods. Protein composition was determined using size-exclusion high performance liquid chromatography. Flour particle size and starch granule size were measured with laser diffraction. Tortillas were made with a laboratory hot press method. Tortilla shelf-stability over 14 days, opacity, appearance, dough machinability and specific volume were measured. Data collected from flour and tortilla tests were analyzed using ANOVA and means were compared with Tukey-Kramer HSD. In general, the flours did not differ significantly in flour or tortilla properties. Regression analysis (Pearson) showed flour protein content was highly and significantly correlated with tortilla opacity (r=-0.81), L color value (r=-0.79), a color value (r=0.80), and day 14 shelf-stability (r=0.76). Flour water absorption showed highly significant correlations with tortilla opacity (r=-0.81), L color value (r=-0.79), a color value (r=0.77) and day 14 shelf-stability (r=0.73). Tortilla opacity was highly correlated with B-type starch granules (r=-0.83). This study showed that starch granule size, flour protein content and flour water absorption appeared to influence tortilla appearance. However, repeating the study with a larger and more diverse sample set is recommended.

Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Candice Shoemaker / Agriculture is a driving industry for most areas of the United States, and the Great Plains region is no exception. In the state of Kansas, agriculture is the primary industry capturing a spot in the USDA 2012 Census of Agriculture’s Top 10 states for total agricultural sales, total crop sales, and total livestock sales (USDA, 2012). Despite the thriving agricultural industry, little research has been completed on the food systems supporting Kansas communities. What are the characteristics of a local food system within the fabric of an agriculturally rich state? The goal of this study was to evaluate the characteristics and perceptions of the local food system supporting Manhattan, Kansas – a metropolitan area located in North Central Kansas. Specifically, we wanted to understand producer barriers to expanding beyond direct markets into institutional markets such as school dining services, grocery stores, and hospital food services. The objectives were to 1) understand producer concerns for selling to institutions, 2) identify resources producers need to access institutional markets, 3) understand institutional preferences for local purchasing, and 4) understand producer and institution definitions of “local” food. In February 2013, a survey was mailed to 162 Kansas producers identified within a 150 mile distance of Manhattan, Kansas. The response rate was 63% and descriptive statistics were completed. Interviews were completed with eleven local institutions in March/April 2013. Common themes were qualitatively assessed. In general, farms were small-scale, producing a diversity of products, and utilizing direct-to-consumer markets while selling to institutions on a limited basis. Producer concerns for selling to institutions included low prices, small production quantities, and delivery costs. Institution concerns included product quantities, quality, and seasonality, quality of communication, and food safety. There was no consensus on a definition for “local” food systems. Opportunities for developing the local food system of Manhattan, Kansas include increasing seasonal production, increasing producer access to resources, and fostering relationships between local producers and institutions.

Master of Agribusiness / Department of Agricultural Economics / Vincent Amanor-Boadu / Bunge is a global agribusiness company that has invested in a facility to produce extruded ingredients and inclusions in its Woodland, California rice mill. Because Bunge is not a branded food manufacturer, it is in a unique position to be a contract manufacturer to a variety of customers without the potential for a conflict of interest. Also, because Bunge is primary in three of the most common ingredients for extruded products, corn, rice and oil, this would be a move down the value chain that would allow it to be more competitive. The initial investment in Woodland has allowed Bunge to learn more about the manufacture of extruded ingredients and inclusions and also gauge overall market demand. A possible next step would be to build a second facility in the eastern half of the United States to expand capacity and be geographically situated to supply the Midwest, South and Northeast regions of the U.S. In order to begin exploring the possibility of a greenfield expansion into the contract manufacture of extruded ingredients and inclusions, this thesis considers three subjects. The first is a customer survey case study, which discovers the customer found high price and whether or not the manufacturer was considered a strategic partner to be the most significant factors in how desirable a manufacturer is. The second subject considered is the ideal location for a second manufacturing site based on a number of factors, including distance from both the customer base and inputs, labor issues, and any savings associated with a particular site. It was found that distance from the ultimate customer may be less important overall than the other factors. The third and final component of the research involved conducting a financial feasibility study. The analyses were conducted under alternative scenarios and subjected to a sensitivity analysis on a number of crucial variables. The weighted average NPV for the alternative scenarios was about $31 million and the IRR of 13.8% cleared the company’s investment hurdle rate. The payback period was estimated to be just under six years. All these suggest that the project as presented in this research is feasible and any investment in it, subject to the absence of any unforeseen event, will be profitable. It is hoped that this information can be used as a starting point and a guide to consider a future investment based on demand and other market indicators available at the time such a decision is required.