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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

The effects of maturity differences on competition between adjacent rows of Sorghum bicolor varieties at two levels of soil moisture

Bisso Eya, Joseph, 1955- January 1989 (has links)
The objective of the study was to determine if and how grain sorghum hybrids (Sorghum bicolor (L.) Moench) of different maturity dates compete with one another when planted in adjacent rows under different moisture levels. Five sorghum varieties differing in their maturity were used: Taylor Evans Y-101-G coming to mid-bloom in 71 days, RS 610, Asgrow Corral, DK 64 and DK 69 coming to mid-bloom in 56.9 days, 61 days, 69.3 days and 75.6 days respectively. Six agronomic characters were measured to determine the effect and extent of competition. They included the number of days to mid-bloom, tiller ratio, grain yield, grain test weight and 300-seed weight. According to the results, adjacent row competition took place due to differences in maturity date for grain yield and 300-seed weight. An almost equilibrium appeared between loss or gain of border rows compared to the loss or gain of the middle row. Also the length of time between day to mid-bloom of the border rows hybrids and the center row genotype was important in the extent of competition effects.
72

The influence of variable amounts of irrigation water and nitrogen fertilizer and their interaction on the development, growth and nitrogen uptake of grain orghum.

Refay, Yahya Ali. January 1989 (has links)
The influence of variable amounts of irrigation water and nitrogen fertilizer and their interaction on the development, growth, grain yield and nitrogen uptake of grain sorghum were studied under monocrop (May 21 planting) and simulated double crop (July 1 planting) in the 1985 growing season and under monocrop in the 1986 growing season. Six grain sorghum hybrids, three of which had a higher grain yielding ability and the other three with a lower grain in yielding ability, were used in this study conducted at the University of Arizona, Marana Agricultural Center. All six hybrids were grown under two planting dates (May 21, July 1), two levels of irrigation water (dry, wet), and two levels of nitrogen fertilizer (0, 112 kg N/ha) in the 1985 growing season. In the 1986 growing season, two hybrids were grown under three levels of irrigation water (dry, medium, and wet) and three levels of nitrogen fertilizer (0, 84, 168 kg N/ha). Planting on May 21 (monocrop) had more days to 50% bloom, leaf area, heads number, grain yield and total dry weight than the July 1 planting (double crop). However, planting on July 1 produced a longer head exsertion (peduncle length) compared to May 21 planting. Head length, plant height, 500 seed weight, and grain volume-weight were not affected by planting date. Water stress reduced head exsertion, head length, plant height, head number, 500 seed weight, grain yield and total dry matter. However, numbers of days to 50% bloom were increased by dry treatment. Leaf area and grain volume-weight were not significantly affected by water levels. Under the conditions of this study, nitrogen fertilizer rates did not produce an effect on most of the agronomic characteristics of grain sorghum hybrids studied in this experiment. However, increased nitrogen fertilizer rates increased the uptake and nitrogen concentration in all growth stages of hybrids in the 1986 growing season.
73

PRODUCTION CHARACTERISTICS OF HYBRID GRAIN SORGHUMS UNDER THREE PLANT POPULATIONS AND TWO PLANTING DATES.

Saeed, Mohammed Ahmed, 1940- January 1986 (has links)
No description available.
74

Determination of the rate and distance of pollen-mediated gene flow in sorghum using cytoplasmic male sterile varieties

Mailula, Nicodemus Mahlehlenyane January 2013 (has links)
Thesis (M.Sc. Agric. (Crop Science)) --University of Limpopo, 2013 / The study aims to provide insights into the nature and extent of development funding provided to various poverty eradication projects by the National Development Agency (NDA) and its subsequent impact on reducing poverty in the predominantly rural communities of the Makhuduthamaga Municipality in the Limpopo Province. It examines in detail the impact made by the NDA on community development through the disbursement of funds to poverty eradication projects. It also provides insights into the total number of the NDA-funded projects and the total proportion of the NDA-funds allocated to them in the Makhuduthamaga Municipality. The study further examines the nature of the NDA support regarding the design of the interventions, relevance, participation of communities, delivery modalities and sustainability. The effectiveness of the NDA-funded projects in community development is determined using employment opportunities created, income generated, skills transferred, assets accumulated, sustainability mechanisms and community empowerment indicators. Although all of these indicators are found to be tightly linked to the NDA’s mandate of poverty eradication, the extent to which the NDA has achieved its objectives in disbursing development funding earmarked for poverty eradication and strengthening of CSOs was yet to be determined, hence the relevance of this study. The study, therefore, highlights key issues regarding the types of employment opportunities created and levels of income emanating from the NDA-funded projects. The study further highlights various areas of community empowerment, financial and sustainability measures put in place for the sustainability of the NDA-funded projects. Using a combined method of research, that is the qualitative and quantitative case study approach, the study highlights in detail insights into the impact made by the NDA on community development, particularly on Makhuduthamaga Municipality. The study highlights that while the NDA made some strides in the creation of employment opportunities, income generation, food security and community empowerment, both financial and institutional sustainability proved to be a daunting challenge for the NDA-funded projects Tailor-made and accredited training interventions coupled with the introduction of market-driven products to the NDA-funded projects as opposed to heavy reliance on donor funding will go a long way in bringing about productivity and, most probably, positive balance sheets and the maximum impact on the NDA funded projects.
75

Efficient utilization of water and nitrogen resources for grain sorghum under rainfed conditions

Abunyewa, Akwasi A. January 2008 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Mar. 10, 2009). PDF text: xix, 194 p. : ill. (some col.) ; 14 Mb. UMI publication number: AAT 3336804. Includes bibliographical references. Also available in microfilm and microfiche formats.
76

Effect of some environmental factors on the accumulation of HCN and NO₃-N in some sorghums

Gorashi, Ahmed Mohamed. January 1900 (has links)
Thesis (Ph. D.)--Wisconsin. / Vita. Includes bibliographical references (leaves 63-70).
77

Malted and fermented sorghum as ingredients in composite bread

Hugo, Leda Florinda 10 October 2005 (has links)
The possibililty of using the simple technologies of malting and fermentation to modify endogenously the sorghum grain components, to alleviate the grittiness, dryness and high crumb firmness caused by the inclusion of sorghum flour in composite bread, was investigated. The most suitable grain and the optimal malting time for sorghum for bread¬making, were selected by malting five sorghum cultivars, up to 8 days, and evaluating them for the highest protein modification and lowest dry matter losses. On that basis, a 6¬days malt of Local White, a relatively high protein sorghum (10.7%), was selected. Sorghum malt flour potentially suitable for bread-making was produced by boiling the selected malt, rather than drying it at high temperatures, stewing or steaming. Boiling was most effective in inactivating the amylases and in increasing the pasting viscosity of sorghum malt. The bread made with boiled malt flour (30%) had an improved crumb structure and water-holding capacity, a softer crumb and increased resistance to staling, compared to bread made with sorghum grain flour (30%). Bread-making with reconstituted flours from flour and bran fractions of whole sorghum grain and whole boiled sorghum malt indicated that the bread improving effect of malting and boiling was due to dextrinization and gelatinization of starch, and to the increase of total and water-soluble pentosans, and crude fiber. Dextrinization and gelatinization of starch decreased the gelatinization temperature and the rate of starch retrogradation, thus decreasing the crumb firmness and firming rate of sorghum and wheat composite bread. However, high levels of gelatinized starch decreased dough strength and bread volume. The increase of total pentosans and crude fiber of sorghum malts, caused by germinating grains roots and shoots growth, and the increase of water-soluble pentosans, due to hydrolysis of the non-starch polyssacharides during malting, significantly increased flour and dough water-holding capacity. Thus, crumb structure was improved and crumb firmness and crumb-firming rate decreased. Treatment of sorghum flour with endo-(l-4)-β-xylanase to determine whether endoxylanases could solubilize sorghum pentosans, increased the water-soluble pentosans slightly, indicating the potential of endoxylanases to improve the bread-making quality of sorghum flour. However, heating the endoxylanase treated flour to inactivate the enzyme, so as to determine its specific effect, gelatinized the starch and decreased the bread volume. A natural lactic acid fermentation of sorghum flour, followed by drying at 60°C, decreased the pH of sorghum flour from 6.2 to 3.4 and slightly increased the gelatinized starch and the pasting viscosity of sorghum flour. Apparently, the low pH caused higher loaf volume and improved crumb structure and softness by suppressing the amylases and by increasing the viscosity of dough, and hence increasing its gas-holding capacity. Adding wet fermented sorghum flour directly to wheat flour (sourdough process), as an alternative to drying, further increased the volume and decreased the crumb firmness. Fermentation and drying also improved the protein digestibility of sorghum composite bread. Consumer panel members liked the bread made with boiled sorghum malt flour most, apparently because it was softer, more moist and had a fine malt flavor. They liked the bread made with fern1ented and dried sorghum flour less, apparently because it had a pronounced sour taste. Malting and fermentation can be successfully used to produce acceptable sorghum and wheat composite bread. Fermentation is probably the most suitable technology for poor developing countries because it is simple and effective. Steaming the malt and adding the endoxylanases directly when mixing the dough, to eliminate the flour drying step and to reduce starch gelatinization, should be looked at further. / Thesis (PhD (Food Science))--University of Pretoria, 2005. / Food Science / unrestricted
78

Enzymic decortation of sorghum grain

Siwela, Muthulisi 07 December 2006 (has links)
Sorghum is a drought resistant indigenous African cereal and traditional food crop. Unfortunately. milling sorghum. as is normally done using a Prairie Research Laboratory (PRL)-type abrasive dehuller is not effective. Because in sorghum the germ is integral in the grain. the process of removing the outer bran layers by abrasion leads to high losses, up to as much as 40% if a flour of less than I% fat is to be produced. The pericarp of sorghum is rich in cellulose and hemicelluloses, and the germ, lipids. Specific hydrolytic enzymes should degrade these chemical components and thus remove the bran and germ with minimal loss of grain material. In this work. four industrial enzymes. endo-β-glucanase. xylanase. pectinase and lipase were applied either singly or in combination to two different commercial batches of sorghum to determine whether hydrolytic enzymes could be used to decorticate sorghum grain. Sorghum grain was either de-waxed with hexane or scraped to remove the waxy material on the pericarp and seed coats. The grain was then soaked in a 10% (w/w) solution of either single or combined enzymes in flasks which were then incubated at 50°C in a water bath and left overnight with shaking. SEM showed that endo-β-glucanase caused decortication of the sorghum grain at the seed coat/aleurone layer interface with both the hexane de-waxed grain and the scraped one. The germ was not removed. The results suggested that endo-β-glucanase hydrolysed the exposedpericarp cell wall material and thus loosened the pericarp, and hence its removal. The germ could not be removed perhaps due to the fact that, in sorghum grain the germ/endosperm interface is at right angles to the surface of the grain, thus enzymes have only a small area to act on and all the underlying interface is not accessible. Different endo-β-glucanase concentrations were applied to partially decorticated sorghum grain to establish the optimum concentration to be used to remove the pericarp material to an acceptable level. The lowest level when there was a good decortication effect, as indicated by grain ash content and colour, was at 0.01% endo-β-glucanase concentration (ml/l00 g grain). The effectiveness of enzymic and mechanical decortication was compared in terms of the relationships between decortication yield and grain ash content, and between decortication yield and grain colour. To reduce the grain ash to an acceptable level (about 1.1%), enzyme decortication resulted in about 10% saving in grain material relative to the mechanical process. However. at the same decortication yield. the mechanical process gave a lighter product than the enzymIc process. It appears that endo-β-glucanase can remove the pencarp from sorghum grain at an economically feasible concentration (0.01%). and that there is significant reduction of grain material loss relative to the mechanical process. However, more work needs to be done to improve the colour of the product. and to find a way to remove the germ. / Dissertation (MSc (Food Science))--University of Pretoria, 2006. / Food Science / unrestricted
79

Low alcohol opaque beer quality : influence of malt, mashing conditions and wort dilution

Musarurwa, Margeret 12 July 2006 (has links)
Research was carried out to determine the effect of high temperature mashing, use of short time germinated malt and low gravity fermentation on the quality of sorghum beer. The objective was to produce an acceptable low alcohol opaque beer. Mashing at high temperatures of 65-80°C resulted in lower generation of fermentable sugars with the least being obtained at 80°C leading to production of low alcohol. The main reason being that although beta- and alpha- amylase enzymes are inactivated at high temperatures beta-amylase is less temperature resistant than alpha-amylase. Thus the reduction in beta-amylase activity leads to reduction in the amount of fermentable sugar in the wort. The best low alcohol product was produced at 75°C. At 80°C although low alcohol was achieved than at 75°C there was the problem of poor body of the beer. On the other hand malt germinated for shorter period of time produced beers almost as good as those of the control brew. Only malt germinated for one day gave alcohol slightly lower than control. This shows that malt irrespective of having been germinated for 1, 2 or 3 days can produce an excellent product as long as the germination reached required levels during malting process so as to have a malt with sufficient diastatic power. Low gravity fermentation revealed that very low alcohol could be achieved by this method but dilution of wort meant also dilution of other beer characteristics resulting in a product which was watery and had no flavour. The major effect of diluting wort was that the content of fermentable sugars was reduced proportionally. However, the product of a 30% dilution was still acceptable since although alcohol was low, texture and flavour of the product were still reasonable. Thus mashing at 75°C, use of malt germinated for one day and method of 30% dilution can be recommended for the production of low alcohol opaque beers. / Dissertation (M Inst Agrar ( Food Processing))--University of Pretoria, 2006. / Food Science / unrestricted
80

Processing of polyphenol-rich sorghums for food

Beta, Trust 03 August 2007 (has links)
Please read the abstract in the section 00front of this document Copyright 1997, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Beta, T 1997, Processing of polyphenol-rich sorghums for food, PhD thesis, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-08032007-125938 / > / Thesis (PhD (Food Science))--University of Pretoria, 2007. / Food Science / unrestricted

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