Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 13 of 13
Full-Text Articles in Life Sciences
Growth And Development Of Oat (Avena Sativa L.) Cultivars In Response To Water Stress, Abdel-Fattah H. Belal
Growth And Development Of Oat (Avena Sativa L.) Cultivars In Response To Water Stress, Abdel-Fattah H. Belal
Electronic Theses and Dissertations
Water stress occurs frequently in the North Central Plains and causes significant reductions in plant growth, development and grain yield. These effects of water stress apparently are dependent on the ability of plants to adapt to less than optimal environments. Plant water potential is dynamic, changing not only with the soil water content and atmospheric conditions, but also with the stage of growth. When plant water potentials become limiting, various physiological processes associated with plant growth, development and final yield are affected. The reduction in productivity in semi- arid environments is directly related to the inability of crop plants to …
The Effect Of Soil Storage Methods And Soil Microbes On Carbofuran And Terbufos Degradation, Muriel Monteleone Runholt
The Effect Of Soil Storage Methods And Soil Microbes On Carbofuran And Terbufos Degradation, Muriel Monteleone Runholt
Electronic Theses and Dissertations
The purpose of this research was to determine optimal soil storage methods for soils used in carbofuran and terbufos degradation studies. The effect of soil microbes on degradation was also observed. An LD50 study, using 22 day old crickets (Acheta domestica), was undertaken to establish the appropriate LC dose for carbofuran in the soil storage studies. A carbofuran use history failure soil and a noninsecticide use history soil of the same type were collected from the SDSU experimental farm in Centerville, South Dakota. After initial degradation and microbial analysis, the soils were stored air-dried and with a moisture level …
Genetics Of Flower Abortion And Pod Type In Soybean, Krishna P. Sharma
Genetics Of Flower Abortion And Pod Type In Soybean, Krishna P. Sharma
Electronic Theses and Dissertations
Field studies were conducted in 1982, 1983 and 1984 in ten soybean (Glycine max (L.) Merrill) genotypes of maturity group 00 to III, to evaluate the effects of genotype and year on flower abortion (FA), flowers/raceme (FPR), raceme length (RL), pod types (PT), seeds/raceme (SPR), seed weight (SW), and yield/raceme (YPR). Reproductive efficiency index (REI) was calculated for parental genotypes and their segregating populations. The effects of main stem node position and raceme flower position on FA and PT were also studied. Genetic studies were on F2's of 13 crosses plus F3 and F4 generations of …
Atrazine And Cyanazine Interception And Retention On Crop Residue, Mark A. Wrucke
Atrazine And Cyanazine Interception And Retention On Crop Residue, Mark A. Wrucke
Electronic Theses and Dissertations
The effect of several variables on herbicide interception and retention by crop residue was investigated. Variables considered include residue type and amount, amount of rain, time of rainfall occurrence, and herbicide formulation. Experiments were conducted in the greenhouse using corn (Zea mays), soybean (glycine max), and wheat (Triticum aestivum) residue. Simulated rainfall was applied using a modified potsprayer. Herbicide concentration in washoff water was determined using the pyridine-alkali colorimeteric technique for chloro-s-triazine herbicides. As the percent ground cover increased, the amount of herbicide reaching the soil surface at application decreased. With normal residue levels attained in South Dakota, 60% or …
Technology And Economics Of Commercial Scale Ethanol Production From Fodder Beets, William Ray Gibbons
Technology And Economics Of Commercial Scale Ethanol Production From Fodder Beets, William Ray Gibbons
Electronic Theses and Dissertations
Fodder beets yield two to three times more fuel ethanol per hectare than corn. This increased productivity should reduce feedstock costs and, consequently, ethanol production costs. The major factor that has limited use of this crop is the lack of a proven technology to process fodder beets -- economically and energy efficiently -- to fuel ethanol on a commercial scale. Research reported herein rectifies this situation by examining the technical and economic feasibility of community scale fuel ethanol production from fodder beets using two novel, continuous fermentation systems solid-phase fermentation and diffusion fermentation. Laboratory scale, batch fermentation trials were first …
Implanting Effects On Performance, Carcass Characteristics And Reproductive Parameters In Intact Beef Males, Shirley J. Gordon
Implanting Effects On Performance, Carcass Characteristics And Reproductive Parameters In Intact Beef Males, Shirley J. Gordon
Electronic Theses and Dissertations
The research presented herein was designed to determine the effects of post-weaning implanting on performance, carcass characteristics, hormonal profile and reproductive parameters.
A Comparison Of High-Performance Short-Duration And Repeated-Seasonal Grazing Systems, Jerry David Volesky
A Comparison Of High-Performance Short-Duration And Repeated-Seasonal Grazing Systems, Jerry David Volesky
Electronic Theses and Dissertations
Six replications of l-herd 16-subunit High-Performance Short-Duration (HPSDG) and Repeated-Seasonal (RSG) (May-Sep.) grazing system treatments were compared during 1983 and 1984 at the Cottonwood Range and Livestock Research Station located in western South Dakota. Calves and lambs were allotted to the experimental pastures in sets approximately equal on an animal unit basis. Animal numbers were adjusted with put-and-take sets to attain planned forage levels for each cycle of rotation in HPSDG and comparable end of season forage use levels in both treatments. The HPSDG system was operated with four cycles of rotation that had 1, 2, 2 and 3 occupation …
Predicted Response To S1 Selection For Agronomic And Disease Resistance Traits In Two Sunflower Populations, Syed Sadaqat Mehdi
Predicted Response To S1 Selection For Agronomic And Disease Resistance Traits In Two Sunflower Populations, Syed Sadaqat Mehdi
Electronic Theses and Dissertations
Variances, heritabilities, genetic and phenotypic correlations, and predicted gains were computed for quantitative disease resistance and agronomic traits from pooled S1 family data of Gene Pool II and ND 761 Helianthus annuus L. populations. Broad-sense heritability estimates for all traits were significant in both populations. Observed genotypic correlation coefficients were larger than their corresponding estimates of phenotypic correlation coefficients. Significant positive genetic correlations between resistance to Alternaria blight and Septoria leaf spot; and non-significant genetic correlations between Sclerotinia wilt disease reaction and agronomic traits were observed in both populations. Resistance to Phoma black stem was not significantly correlated with resistance …
Modeling Of Soil Water Flow And Root Uptake, V. Rasiah
Modeling Of Soil Water Flow And Root Uptake, V. Rasiah
Electronic Theses and Dissertations
The soil water pressure head, h, versus soil water content, 9, and the hydraulic conductivity, K, versus θ, relationships appear as functional coefficients in the non-linear partial differential water flow model. Before the flow equation can be used to simulate the flow of water through soils, the h versus θ and K versus θ relationships must be established. This requires the estimation of the parameters that describe the h versus θ and K versus θ functional relationships. In-situ water retention and hydraulic conductivity measurements were determined from the knowledge of initial and boundary conditions and water content profiles during drainage. …
The Relationship Between Reciprocal Spring By Winter Wheat Crosses And The Contribution Of Their Parents To Hybrid Performance, George Warren Partelow
The Relationship Between Reciprocal Spring By Winter Wheat Crosses And The Contribution Of Their Parents To Hybrid Performance, George Warren Partelow
Electronic Theses and Dissertations
Five diverse spring and five diverse winter wheat cultivars were crossed in all possible spring by winter combinations including their reciprocals to determine whether agronomic differences in reciprocal spring by winter crosses occur, and to determine the relative contribution of spring and winter parents to general and specific combining ability. Traits examined in the F1 generation in this greenhouse study included: 1) grain yield (g/plant) 2) number of spikelets per spike 3) total kernel weight (g) per spike 4) number of kernels per spike 5) number of tillers per plant 6) weight (g) of 100 kernels 7) length (mm) of …
Nutritional Factors Modifying Fatty Liver Hemorrhagic Syndrome In Caged Laying Hens, Chandi C. Rakshit
Nutritional Factors Modifying Fatty Liver Hemorrhagic Syndrome In Caged Laying Hens, Chandi C. Rakshit
Electronic Theses and Dissertations
Three experiments each with two phases were conducted to study the effect of different levels of distillers dried grain (DDG), fat, oats and a mixture of oats and DDG on Fatty Liver Hemorrhagic Syndrome (FLHS) in caged laying hens. The second phase of each experiment was conducted by force-feeding the same diets used in the first phase at 120% of their normal intakes. This produces FLHS and thereby permits studying the effect of diets. During the force-feeding period of the third experiment, serum estradiol levels of hens from each treatment and each type of feeding were measured to study the …
Lactational And Systemic Responses To The Supplementation Of Protected Methionine In Soybean Meal Diets, Daniel J. Illg
Lactational And Systemic Responses To The Supplementation Of Protected Methionine In Soybean Meal Diets, Daniel J. Illg
Electronic Theses and Dissertations
The high producing dairy cow requires a complex balance of protein and energy. Microbial protein provides a substantial amount of the amino acids absorbed by the small intestine. High production rates cannot be attained with microbial protein as .the sole source of amino acids. The ten classical essential amino acids are required for milk protein synthesis. Increasing the amount of available amino acids to the mammary gland has improved casein production, indicating substrate availability as a controlling factor to milk protein synthesis. A major portion of the nitrogen component of milk is derived from free plasma amino acids. Uptake by …
Inhibition Of Psychrotrophic Bacterial Growth In Refrigerated Milk By Addition Of Carbon Dioxide, Robert Francis Roberts
Inhibition Of Psychrotrophic Bacterial Growth In Refrigerated Milk By Addition Of Carbon Dioxide, Robert Francis Roberts
Electronic Theses and Dissertations
The advent of on-farm refrigerated storage for raw milk in the late 1940's and its subsequent adoption by North American dairyman 'during the next 20 years essentially eliminated spoilage of milk by lactic acid bacteria. However, refrigeration does not prevent growth of all microorganisms present in raw milk (9, 33, 51, 52, 54, 55). Many microorganisms capable of growth at refrigeration temperatures, termed psychrotrophic bacteria, are present as normal contaminants in raw milk supplies. For purposes of clarity, psychrotrophic microorganisms have been defined as microorganisms capable of growth at 7°C or below regardless of their optimum growth temperature (9). Milk …