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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.
101

EVALUATIONS OF STEROL-INHIBITING FUNGICIDES FOR CONTROL OF PHYMATOTRICHUM ROOT ROT OF COTTON.

WHITSON, ROY S. January 1984 (has links)
Eight "sterol-inhibiting" fungicides were evaluated for in vitro activity against Phymatotrichum omnivorum, and all proved to be very active (EC-50 values ranged from 0.001-0.038 ug/ml). Propiconazol received the major emphasis of this research, which included evaluations of phytotoxicity, soil persistance, resistance development, systemic translocation in cotton, and field evaluations for control of Phymatotrichum Root Rot of cotton. Although propiconazol significantly inhibited mycelial growth of P. omnivorum (in vitro) at concentrations as low as 0.0001 ug/ml within 96 hr, hyphal growth from sclerotia was not affected at 0.1 ug/ml within the same time frame. However, after 168 hr, or if sclerotia were pre-germinated for 120 hr before exposure, growth inhibition was comparable to that of the mycelial cultures. It was speculated that the greater level of sterols in sclerotia masked the inhibition of sterol synthesis by propiconazol until these sterol reserves were depleted. After 5 exposures to propiconazol over a 5 mo period, mycelial growth inhibition was the same as that of mycelium with no previous exposure. This indicated that resistance development should not be an immediate concern. Greenhouse evaluations of phytotoxicity and soil persistance of propiconazol determined that this fungicide can severely stunt cotton if planted into treated soil. Using stunting of seedlings as a bioassy of the persistance of propiconazol in non-sterilized soil, it was found that propiconazol was still active 3-5 mo after the initial soil treatment. Through the application of C-14 labeled propiconazol to the leaves of 5 and 8-wk old cotton plants, it was determined that no more than 0.23% of the applied radioactivity was translocated to the roots. However, based upon these percentages, root weights of the plants, and the amount of propiconazol applied to each plant during a field application, the theoretical concentration in the roots would be 30-700X the in vitro concentration necessary to inhibit mycelial growth of P. omnivorum (EC-50 = 0.003-0.006 ug/ml). Field evaluations of propiconazol were conducted in 1982 and 1983, while etaconazol, triadimefon, triadimenol, imazalil, and XE-779 were evaluated in 1983. These evaluations determined that propiconazol, etaconazol, and triadimenol showed promise for control of this disease, while imazalil, triadimefon, and XE-779 did not. . . . (Author's abstract exceeds stipulated maxium length. Discontinued here with permission of author.) UMI
102

Water relations in cotton plants infected with Phymatotrichum omnivorum

Olsen, Mary Ward. January 1982 (has links)
Water relations in cotton plants infected with Phymatotrichum omnivorum were studied to determine the mechanism of wilt development. Relationships between leaf water and osmotic potentials, relative water contents, and diffusive resistances of leaves from diseased and waterstressed healthy plants were similar, indicating that wilting was not due to changes in leaf osmotic regulation. Rates of recovery from wilting, measured as increases in relative water content with time in both diseased and waterstressed healthy plants were identical. There was no significant difference in root dry weight of healthy and diseased plants, indicating that wilting is not a consequence of reduced root area. Resistance to water flow in roots and lower stems increased significantly over those of healthy plants as upper leaves of diseased plants began to wilt. However, resistance to water flow in petioles of diseased plants was unchanged. These results show that wilting in cotton plants is probably the consequence of increased resistance to water flow in roots. Results of a preliminary study indicate that a high-molecular-weight substance produced by the fungus in culture may cause blockage of xylem elements in roots and lower stems and contribute to the increased resistance to water flow.
103

Experimental determination of in-situ serviceability of Sitka spruce timber by ultrasonic non-destructive testing

Chapman, Michael James January 2001 (has links)
No description available.
104

Biological and chemical control of Pythium butleri on tomato

El Masry, Mousa Ahmed January 1987 (has links)
No description available.
105

Decolorisation of phenolic industrial wastes using Trametes versicolor

Summerwill, Michah January 1994 (has links)
No description available.
106

EVALUATION OF WHITE ROT FUNGUS AS A PRETREATMENT FOR THERMOCHEMICAL PROCESSING OF SWITCHGRASS

Embry, Melody 01 January 2018 (has links)
Hydrothermal liquefaction is a thermochemical technique for obtaining crude bio-oil from lignocellulosic biomass with moderate temperature and pressure. The crude bio-oil can then be upgraded to various biofuels and bioproducts. Hydrothermal liquefaction is amenable to use of biomass feedstocks that have high-moisture. The overall goal of this research is to demonstrate the effectiveness of white rot fungus (WRF) as a pretreatment option in the production of bio-oil from switchgrass through hydrothermal liquefaction. If WRF is an effective pretreatment, it could be a cost-effective option for commercialization, allowing hydrothermal liquefaction to be used on an industrial scale to produce high quality bio-oil capable of replacing some of the fossil fuel liquids used today. This thesis specifically focuses on the investigation of the effects of particle size and culture time on lignin degradation using Phanerochaete chrysosporium as a pretreatment method on switchgrass. In addition, the conversion efficiency of WRF treated switchgrass was compared to that of torrefied switchgrass and untreated switchgrass after the pyrolysis conversion process. The results indicate that WRF outperforms torrefaction as a pretreatment method for the conversion of sugar-based components, thus may be an attractive alternative for fermentation conversion processes, but probably not for thermochemical processes.
107

Effect of resident epiphytic fungi development of brown rot blossom blight of stone fruits

Wittig, Hans P. P. 14 January 1992 (has links)
Antagonistic effects of Epicoccum purpurascens, Aureobasidium pullulans, Trichoderma spp., and Botrytis cinerea on establishment of Monilinia fructicola infections in cherry and peach blossoms were assessed in field and mist chamber studies. Conidia of each fungus were applied to blossoms that were subsequently inoculated with conidia of M fructicola. Mist chamber experiments on forced cherry blossoms demonstrated that recovery of M. fructicola was significantly reduced (P=.05) when spores of E. purpurascens and B.cinerea had been applied 24 hr prior to inoculation with M. fructicola. Reduction in recovery of M. fructicola was comparable to that obtained with the fungicide benomyl. In field trials done in 1990 and 1991, applications of E. purpurascens and A. pullulans reduced cherry blossom blight relative to nontreated blossoms by 47 to 65 and 54 to 58%, respectively, compared to reductions of 80 to 96 and 84 to 97% with the fungicides benomyl and iprodione, respectively. Twig blight in peach, an indicator of blossom blight infection, was reduced by 37% relative to nontreated blossoms with applications of E. purpurascens, compared to 54 and 51% reductions with benomyl and iprodione, respectively. Analysis of the influence of antagonistic fungi sprayed onto blossoms on fruit set indicated that B.cinerea was a weak pathogen of stone fruit blossoms. Significant reductions (P=.05 and P=.10) were obtained in fruit set compared with the nontreated control when conidia of B. cinerea were applied to both cherry and peach blossoms in 1991. Latent Monilinia infections were evaluated by dipping green cherries in the herbicide paraquat. Applications of E. purpurascens and A. pullulans to blossoms caused reductions in the number of latent Monilinia infections in green cherries by 18 and 49%, respectively in 1990, and 61 and 66% respectively in 1991. This compares with reductions of 98 and 92% in 1990 and 1991, respectively, with the fungicide iprodione. It was observed that the antagonists E. purpurascens and B. cinerea also became established as latent infections. These fungi were recovered at a significantly (P=.05) higher percentage on green cherries where they had been applied as antagonists to blossoms. No meaningful differences were detected in the amount of brown rot that developed on fruit due to the influence of fungal treatments on blossoms. / Graduation date: 1992
108

Nondestructive testing (NDT) of Norway spruce with respect to infection by root and butt rot using ultrasound and acoustic methods.

Sturesson, Claes January 2011 (has links)
No description available.
109

Research on the Financial Model That Promotes Participation in Public Works by the Private Sector ¡V Taking Kaohsiung International Youth Hostel as an Example

- Guey, Mei 22 August 2005 (has links)
Abstract According to the idea held by the government, ¡§government has limited resources but the private sector has limitless power,¡¨ the Executive Yuan established and promulgated the enactment, ¡§Promoting the Participation by the Private Sector in Public Works,¡¨ in February 2000. This is a policy that depends on the vitality and capital funds of the private sector to be incorporated for use in a timely manner. This has brought positive meanings and benefits in enhancing government performance, reducing government financial burdens, speeding up the construction of public works, improving the quality of public works and services, and promoting economic growth. The scope and target of this dissertation is the process of planning to regard Kaohsiung International Youth Hostel as a dormitory facility of Kaohsiung Chung-Hwa School of Arts. It is expected, with the investigation of this case, to study how to harmony with related existing laws and regulations, analyze the burdens and favors taken by the participants under various situations, and examine the feasibility of its¡¦ cooperation so that unused government assets, in agreement with the original purpose of such assets, can be fully utilized, enthusiastic artists can have a comfortable housing environment and field where they can exchange art, facilitate the art prosperity in the Fine Arts Museum neighborhood, and then bring in commercial opportunity to help local economic development. Moreover, through this case study, it aims to provide government offices concerned with valuable figures when they conduct related operations so that when executing plans of the same essence, the office-in-charge can achieve more economic benefits and policy objectives. This dissertation used ROT mode to introduce the resources of the private sector into the operation of public works, which will effectively solve the difficulty that government has no choice but to implement the operation of public works even under financial deficits. As a consequence, public works would not fall idle in the wake of short government finances and lack of professional operation, and the public would be encouraged to advocate the plan to recycle and to reuse the unused public works so as to achieve energy conservation and the prospect for the sustainable development of Earth. Through sensitivity analysis on the changes in key parameters, this dissertation has clearly noticed the increase and decrease in various hypotheses and parameters, and will present different effects and evaluate the variable effects of all the parameters. Before it is executed, the effects and impact that may be caused by government, chartered companies, students, and banks should be considered. Before the plan is implemented, risk control measures should be formulated according to the results of sensitivity analysis.
110

The effect of QoI fungicides on monocyclic components of peach brown rot epidemics caused by monilinia fructicola

Burnett, Alison, January 2009 (has links)
Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Plant Biology." Includes bibliographical references (p. 45-48).

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