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Full-Text Articles in Life Sciences

Implications Of Rice Cultivar Selection To Optimize Returns From Crop Insurance, David Ethan Branscum May 2019

Implications Of Rice Cultivar Selection To Optimize Returns From Crop Insurance, David Ethan Branscum

Theses and Dissertations

Rice production differs from most other field crops by distinct differences in yields across cultivars and rice producers being paid for yield after post-harvest milling. Using eleven years (2003-2013) of Arkansas harvest data from performance trials in six different locations, hybrids have 19% higher paddy yields and head rice yield rate 1.7% lower than conventional cultivars. Given the 2014 Farm Bill’s emphasis on crop insurance as a risk management tool for producers, these variations in yield among cultivars have significant implications for rice producers. Comparing national level, crop insurance data on corn, soybeans and rice indicates rice producers ...


Methane Emissions From Rice Production On A Silt-Loam Soil In Arkansas, Joshua Jeffry Humphreys Aug 2018

Methane Emissions From Rice Production On A Silt-Loam Soil In Arkansas, Joshua Jeffry Humphreys

Theses and Dissertations

Methane (CH4) emissions from rice (Oryza sativa L.) production are a source of concern in the environmental and agricultural communities. New and/or revised agronomic methodologies will be needed to identify production practice combinations that reduce CH4 emissions without decreasing yields. The objective of this multi-year study was to evaluate the effects of water management (i.e., full-season flood and mid-season drain) (2015), cultivar (i.e., pure-line cultivar ‘LaKast’ and the RiceTec hybrid “XP753”) (2015), soil organic matter (SOM) concentration (2016), and tillage [conventional tillage (CT) and no-tillage (NT)] and urea-based fertilizers [N-(n-butyl) thiophosphoric triamide (NBPT)-coated urea and ...


Development And Characterization Of Rice Genotypes For Water Use Efficiency And Drought Resistance, Anuj Kumar Dec 2017

Development And Characterization Of Rice Genotypes For Water Use Efficiency And Drought Resistance, Anuj Kumar

Theses and Dissertations

Rice, the second largest staple food crop, uses 30% of global fresh water to complete its life cycle worldwide. Water deficits worldwide have become a serious problem affecting rice growth and ultimately grain yield. To solve the water problem globally, improvement of water use efficiency (WUE) and other drought resistance (DR) traits in rice genotypes would be a useful strategy using advanced genomics tools. In this study, our objectives were to 1) analyze phenotypes of the USDA rice mini-core collection (URMC) for WUE and DR related traits, 2) correlate drought response phenes for physiological traits and grain yield in the ...


Development Of A One Pass Microwave Heating Technology For Rice Drying And Decontamination, Deandrae Lynette Smith May 2017

Development Of A One Pass Microwave Heating Technology For Rice Drying And Decontamination, Deandrae Lynette Smith

Theses and Dissertations

An industrial microwave (MW) system operating at 915 MHz frequency was used to dry high moisture content (MC) (23% to 24% wet basis) medium-grain rough rice samples (cv. Jupiter). The rice beds were contained in a modified tray that accommodated up to 9 kg of rice separated by thin fiberglass mesh in 3 kg increments. Each layer of rice was fitted with fiber optic sensors connected to a real time data logger during MW treatments. It was determined that drying rice to a MC of 14% to 16% was feasible with the application of MW specific energy at 600 kJ ...


Microbes In Rough Rice – Prevalence, Growth Kinetics And Links To Dry Matter Loss, Supriya Thote Aug 2016

Microbes In Rough Rice – Prevalence, Growth Kinetics And Links To Dry Matter Loss, Supriya Thote

Theses and Dissertations

The prevalence of microorganisms on freshly-harvested long-grain hybrid, long-grain pureline, and medium-grain rice has not been elucidated. The first objective of this two-part study was to determine the relative prevalence of microbes on freshly-harvested, high moisture content rice of different types and cultivars. The total and surface aerobic plate counts (APC) and mold counts were determined in terms of log10 colony forming units per gram of rice (log10 CFU/g) for six rice cultivars over two years. In 2013, among harvested samples of all the studied rice cultivars, the long-grain hybrid cultivars had the lowest APC levels (M = 8.10 ...


Effects Of Delayed Drying And Storage Conditions On Milling, Color, And Viscosity Properties Of Rice, Kathryn Nicole Haydon May 2016

Effects Of Delayed Drying And Storage Conditions On Milling, Color, And Viscosity Properties Of Rice, Kathryn Nicole Haydon

Theses and Dissertations

Head rice yields (HRYs), kernel discoloration, and functional properties are three hallmarks of rice quality, and can be impacted after harvest by storage conditions. This study evaluated impacts on rice quality due to controlled storage at moisture contents (MCs), temperatures, and storage durations that may be incurred during Mid-South rice farming practices. Three hybrid, long-grain cultivars, harvested in Arkansas in 2014 and 2015, were stored in rough rice form at 4 MCs (12.5%, 16%, 19%, and 21%), and 5 temperatures (10°C, 15°C, 20°C, 27°C, and 40°C), for 16 weeks, with samples taken every 2 ...


A Simulation Platform For Accurate Prediction Of In-Bin Drying And Storage Of Rough Rice, Houmin Zhong Dec 2015

A Simulation Platform For Accurate Prediction Of In-Bin Drying And Storage Of Rough Rice, Houmin Zhong

Theses and Dissertations

Natural air (NA), in-bin drying and storage of rough rice generally maintains high grain quality, but the associated slow movement and occasional stagnation of the drying front during the process may result in problems of rice quality reduction, mold growth, and mycotoxin development, especially for rough rice in the top layers of the bin. Using modeling techniques to simulate in-bin rough rice drying in typically-encountered field scenarios may provide a tool for rapidly predicting the grain condition as drying progresses. The objectives for this study were to (1) investigate accurate models for predicting equilibrium moisture content (EMC) of rough rice ...


Effect Of Germination And Parboiling On Milling, Physicochemical, And Textural Properties Of Medium- And Long-Grain Rough Rice, Ashley Han May 2015

Effect Of Germination And Parboiling On Milling, Physicochemical, And Textural Properties Of Medium- And Long-Grain Rough Rice, Ashley Han

Theses and Dissertations

Germinated brown rice is commonly consumed in Asia for its enhanced nutritional properties such as gamma-aminobutyric acid (GABA) and softer cooked texture. However germination decreases milling yield and alters some physicochemical properties, and most germinated rice studies evaluated medium-grain and aromatic rice cultivars. This study compared the effects of germination duration and parboiling on milling, physicochemical, and textural properties of a medium- (Jupiter) and a long-grain (Wells) rice cultivars. Rough rice was soaked in water at 25°C for 12 hr, and then incubated at 30-34°C for varying germination durations, or combined with parboiling at 120°C for 20 ...


Milling And Functional Properties Of Co-Mingled Rice Cultivars, Nikhil N. Basutkar May 2014

Milling And Functional Properties Of Co-Mingled Rice Cultivars, Nikhil N. Basutkar

Theses and Dissertations

Differences have been observed in the milling and functional properties of different rice cultivars, particularly between hybrid and pureline cultivars. Co-mingling of rice cultivars commonly occurs during harvest, storage and drying operations. Thus, there is a need to study the effect of co-mingling on the milling and functional properties of rice cultivars. Two long-grain, hybrid (H) cultivars CL XL745 and CL XL729 and two long-grain, pureline (P) cultivars CL 151 and Wells were used to prepare CL XL745/CL 151 (H/P), CL XL745/CL XL729 (H/H) and Wells/CL 151 (P/P) co-mingles, mixed in various proportions. Milled ...


The Effects Of Salinity On Pythium Disease Of Rice And Soybean, Terea Jeanette Stetina Dec 2013

The Effects Of Salinity On Pythium Disease Of Rice And Soybean, Terea Jeanette Stetina

Theses and Dissertations

Increasing salinity is an important factor limiting agricultural productivity worldwide. In addition to direct effects on growth and yield, diseases also may be affected. This study characterized the effects of soil salinity on seedling disease of soybean and rice caused by Pythium spp. Controlled environment experiments on soybean used two cultivars which differed in chloride tolerance and soil treated with a CaCl2 solution to create a range of electrical conductivity (EC) levels. For soybean, soil was either not infested or infested with Pythium sylvaticum or P. aphanidermatum (pathogenic to soybean), or P. oligandrum (not pathogenic to soybean). Twenty-one days ...


A Comparison Of Milled Rice Fissuring Kinetics Of Hybrid And Pureline Cultivars, Semehar Haile Tesfaye Dec 2013

A Comparison Of Milled Rice Fissuring Kinetics Of Hybrid And Pureline Cultivars, Semehar Haile Tesfaye

Theses and Dissertations

Over the past decade, the use of hybrid rice cultivars has greatly increased, and this has led to questions about the processing behavior of hybrid cultivars. This study compares the milled rice fissuring kinetics of hybrid and pureline cultivars. Also, this study elucidates the effects of kernel type (long-grain vs. medium-grain rice cultivars), surface lipid content (SLC), and kernel thickness on fissuring rates.

Three hybrid (CL XL745, CL XL729 and XL753) and five pureline (Wells, CL151, Cheniere, Jupiter and CL261) cultivar lots were procured. Jupiter and CL261 are medium-grain cultivars, whereas the rest are long-grain cultivars. Two experiments were conducted ...


Single-Pass Drying Of Rough Rice Using Glass Transition Principles, George Owira Ondier Aug 2012

Single-Pass Drying Of Rough Rice Using Glass Transition Principles, George Owira Ondier

Theses and Dissertations

The objective of this research was to study the drying characteristics, milling quality, and functional properties of rough rice subjected to single-pass drying while controlling kernel material states. Drying experiments were conducted at 60, 70, and 80C and relative humidities ranging from 13 to 83%. High drying air relative humidities (greater than 63%) maintained both the kernel surface and core in a rubbery state during drying, whereas low drying air relative humidities caused rapid transitioning of the surface layers from a rubbery to a glassy state. Long-grain pureline cultivar, Wells, medium-grain pureline cultivar, Jupiter, and long-grain hybrid cultivar, CL XL729 ...


Development And Utilization Of Resistant Starch In Cooked Rice Grains And Breads, Michaael Reed Jan 2012

Development And Utilization Of Resistant Starch In Cooked Rice Grains And Breads, Michaael Reed

Graduate Theses and Dissertations

This thesis consists of two separate studies. The first is titled "Effects of Cooking Methods and Starch Structure on Starch Hydrolysis Rates of Rice", and the second one is "Application of a Novel Resistant Starch in Bread: Composition, Structure and Sensory Analysis". With concerns over diabetes, there is a need to find methods of cooking rice to reduce the rate of glucose release after ingesting. Comparing between steamed, stir-fried and pilaf rice, stir-fried rice displayed the slowest starch-hydrolysis rate and the largest resistant starch (RS) content followed by pilaf rice and steamed rice. RS in food is not readily hydrolyzed ...


Biochemical Investigations Of Black Gram (Phaseolus Mungo L.) And Rice (Oryza Sativa L.) Proteins And Their Improved Nutritional Functionality In The Fermented Product- Idli, Vinodkumar W. Padhye May 1978

Biochemical Investigations Of Black Gram (Phaseolus Mungo L.) And Rice (Oryza Sativa L.) Proteins And Their Improved Nutritional Functionality In The Fermented Product- Idli, Vinodkumar W. Padhye

All Graduate Theses and Dissertations

The objectives of this investigation have been to characterize black gram (Phaseolus Mongo L.) and rice (Oryza sativa L.) proteins and to study changes in their nutritional value due to fermentation. black gram, the legume chosen for this work, is one of the most important legume crops throughout a large part of the tropics.

The protein content of 60 mesh, dehydrated, defatted black gram meal was 28.5 percent. Sodium carbonate (0.5- 1.0 percent), tetra-sodium pyrophosphate (0.5 percent), and sodium dodecyl sulfate (SDS) (0.5-5 percent) proved to be the potential protein solubilizers as they extracted more ...