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Potential cucurbitacin chemical residues and non-phytotoxic concentration of two phytonematicide formulations in nightshadeMalebe, Agreement Leago January 2019 (has links)
Thesis (M. A. Agriculture (Plant Protection)) -- University of Limpopo, 2019 / The successful cultivation of nightshade (Solanum retroflexum) as a leafy vegetable with
the nutritional potential of contributing to food security in marginalised communities of
Limpopo Province could be limited by high population densities of root-knot (Meloidogyne
species) nematodes. However, the use of Nemarioc-AL/AG and Nemafric-BL/BG
phytonematicides in suppressing nematodes and not being phytotoxic requires the
empirically-developed non-phytotoxic concentration, technically referred to as Mean
Concentration Stimulation Point (MCSP). The MCSP, developed using the Curve-fitting
Allelochemical Response Data (CARD) computer-based model, is crop-specific, hence it
should be developed for every crop. The objective of this study was to investigate the
influence of Nemarioc-AL/AG and Nemafric-BL/BG phytonematicides on growth of
nightshade, accumulation of essential nutrient elements and cucurbitacin residues in
nightshade leaves. Microplots were established by inserting 20-cm-diameter plastic pots
into 10-cm-deep holes at 0.6 m intra-row and 0.6 m inter-row spacing. Each pot was filled
with 10 000 cm3 steam-pasteurised river sand and Hygromix at 3:1. After establishment,
Nemarioc-AL and Nemafric-BL phytonematicides were applied at 7-day interval, whereas,
Nemarioc-AG and Nemafric-BG phytonematicides were only applied at planting. Two
separate experiments for Nemarioc-AL and Nemafric-BL phytonematicides were
conducted in summer (November-January) 2017/2018 under microplot conditions with
each comprising treatments namely; 0, 2, 4, 8, 16, 32 and 64%, similarly, two separate
experiments for the following phytonematicides, Nemarioc-AG and Nemafric-BG
comprised treatments namely; 0, 2, 4, 6, 8, 10 and 12 g arranged in a randomised
complete block design (RCBD), with 12 replications. The nutrient elements in leaf tissues
of nightshade were analysed using the inductively coupled plasma optical emission
spectrometry (ICPE-9000) while, cucurbitacin A and B were
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each quantified using the isocratic elution Shimadzu HPLC Prominence with Shimadzu
CTO-20A diode array detector. Plant growth and nutrient elements variables were
subjected to the CARD computer-based model to generate biological indices to generate
the curves, quadratic equations and the related biological indices (Dm, Rh, k) (Liu et al.,
2003). The MCSP values were calculated using the biological indices of plant or nutrient
element variables which, along with increasing concentration of Nemarioc-AL, Nemafric
BL, Nemarioc-AG and Nemafric-BG phytonematicides, exhibited positive quadratic
relations, with R2 ≥ 25. Using cucurbitacin A and B standards, residues of Nemarioc
AL/AG and Nemafric-BL/BG phytonematicides, were not detected in nightshade leaves,
respectively. Dry root mass and dry shoot mass of nightshade over increasing
concentration of Nemarioc-AL phytonematicide each exhibited a quadratic relationship,
with the models explained by 93 and 61%, respectively. Dry root mass, dry shoot mass,
plant height, chlorophyll content and stem diameter against increasing concentration of
Nemafric-BL phytonematicide each exhibited positive quadratic relationships with the
models explained by 95, 72, 65, 78 and 62%, respectively. Plant height, stem diameter
and dry root mass against increasing concentration of Nemarioc-AG phytonematicide
each exhibited positive quadratic relationships with their models explained by 93, 88 and
91%, respectively. Dry shoot mass and stem diameter against increasing concentration of
Nemafric-BG phytonematicide each exhibited positive quadratic relationships with their
models explained by 94 and 84%, respectively. Na, Fe and K over increasing
concentration of Nemarioc-AL phytonematicide each exhibited positive quadratic
relationships with their associations explained by 96, 91 and 95%, respectively. Zn over
increasing concentration of Nemafric-BL phytonematicide exhibited positive quadratic
relationship with the model explained by 98%. Fe over increasing concentration of
Nemarioc-AG phytonematicide exhibited positive quadratic
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relationship with the association explained by 91%. Fe, Na, K and Zn over increasing
concentration of Nemafric-BG phytonematicide each exhibited positive quadratic
relationships with their associations explained by 81, 90, 80 and 89%, respectively,
whereas, on the contrary, Zn over increasing concentration of Nemarioc-AG
phytonematicide exhibited negative quadratic relationship with the association
explained by 96%. Significant (P ≤ 0.05) plant variables were subjected to CARD, to
generate biological indices which were used to compute the MCSP using the relation:
MCSP = Dm + Rh/2 and the overall sensitivity value (∑k). In Nemarioc-AL
phytonematicide trial, MCSP = 3.02% and ∑k = 1 for plant variables, whereas, MCSP
and ∑k for nutrient elements were 12.09% and 1, respectively. In Nemafric-BL
phytonematicide trial, MCSP = 3.08% and ∑k = 0 for plant variables, while MCSP =
2484.14% and ∑k = 0 for nutrient elements. In Nemarioc-AG phytonematicide trial,
MCSP = 3.47 g and ∑k = 0 for plant variables, whereas, for nutrient elements MCSP =
8.49 g and ∑k = 1. In Nemafric-BG phytonematicide trial, MCSP = 4.70 g and ∑k = 0
for plant variables, whereas, MCSP =723.75 g and ∑k = 1 for nutrient elements. In
conclusion, the application of Nemarioc-AL/AG and Nemafric-BL/BG phytonematicides
had the ability to stimulate the growth of nightshade and enhance the accumulation of
the selected nutrient elements without leaving cucurbitacin chemical residues in leaf
tissues of nightshade. / National Research
Foundation (NRF)
and the Land Bank Chair of Agriculture
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Mean concentration stimulation point of nemarioc-AL and nemafric-BL phytonematicides on pelargonium sidoided : an indigenous future cultigenSithole, Nokuthula Thulisile January 2016 (has links)
Thesis (MSc. (Horticulture)) -- University of Limpopo, 2016. / Pelargonium sidoides has numerous medicinal applications, with economic potential to
serve as a future cultigen in smallholder farming systems. However, it is highly
susceptible to the root-knot (Meloidogyne species) nematodes, without any identifiable
nematode resistant genotypes. Nemarioc-AL and Nemafric-BL phytonematicides, with
cucurbitacin A and cucurbitacin B active ingredients, respectively, are being researched
and developed as an alternative to synthetic nematicides at the University of Limpopo.
However, since active ingredients in phytonematicides are allelochemicals, the two
phytonematicides have the potential of inducing phytotoxicity on crops protected against
nematode damage. The objectives of the study, therefore, were (1) to determine the
non-phytotoxic concentration of Nemarioc-AL phytonematicide on plant growth of P.
sidoides, and (2) to determine the non-phytotoxic concentration of Nemafric-BL
phytonematicide in plant growth of P. sidoides. Cuttings were raised in 30-cm-diameter
plastic pots containing 10 000 ml steam-pasteurised river sand and Hygromix-T at 3:1
(v/v) under microplot conditions in autumn (March-May) and repeated in spring (August
October) 2015. After establishment each plant was inoculated with 5 000 eggs and
second-stage juveniles (J2s) of M. javanica. Six treatments, namely, 0, 2, 4, 6, 8 and
10% concentrations of each phytonematicide on separate trials were arranged in a
randomised complete block design, with seven replicates. At 56 days after inoculation,
in Experiment 1, Nemarioc-AL phytonematicide, treatment significantly (P ≤ 0.05)
affected plant height, dry root mass and root galls, contributing 62, 69 and 70% to total
treatment variation of the three variables, respectively. Relative to untreated control
Nemarioc-AL phytonematicide increased plant height and dry root mass by 34 to 61%
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and 20 to 76%, respectively, with a slight decrease by 5% in plant height at the highest
concentration. However, the material decreased root galls by 5 to 50%. Significant (P ≤
0.05) plant variables were subjected to Curve fitting-allelochemical respond dosage
model, to generate biological indices which were used to compute the mean
concentration stimulation point (MCSP) using the relation: MCSP = Dm + Rh/2 and the
overall sensitivity value (∑k). In Experiment 1, MCSP = 6.18% and ∑k = 3. Plant
variables and increasing concentration of phytonematicide exhibited quadratic relations.
Treatments reduced nematode variables, at all levels including at the lowest, but the
effect were not different. In Experiment 2, Nemarioc-AL phytonematicide treatment
effects were not significant on plant variables except for root galls, but were significant
for root nematodes except for eggs. Data for plant variables in Experiment 2 were not
subjected to Curve fitting-allelochemical respond dosage model because they were not
significant (P ≤ 0.05). In Experiment 1, Nemafric-BL phytonematicide treatment
significantly (P ≤ 0.05) affected plant height and root galls, contributing 63 and 67% to
total treatment variation of the two variables, respectively. Relatively to untreated
control, plant height was increased by 10 to 36%, while root galls was reduced by 2.43
to 60%. In Experiment 1, MCSP = 2.87% and ∑k = 3. Concentrations of Nemafric-BL
phytonematicide significantly (P ≤ 0.05) reduced eggs, juveniles and Pf at all levels
including at the lowest, but the effect were not significant different, with treatments
contributing 78, 72 and 90% to the total treatment variation. In Experiment 2, Nemafric
BL phytonematicide treatment effects were not significant on plant variables except for
root galls, but were significant for root. In conclusion, Nemarioc-AL and Nemafric-BL
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phytonematicides could be applied at the lowest concentration of 2% where it was
shown to be effective in suppressing population densities of M. javanica. / Agricultural Research Council (ARC),
National Research Fund (NRF) ,
Flemish Inter university Council of Belgium and
Land
Bank Chair of Agriculture ─ University of Limpopo
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Development of mean concentration stimulation point for fermented Lantana Camara Phytonematicide on tomato productionMalatji, Kgashane Philip January 2017 (has links)
Thesis (M.Sc. (Agriculture)) --University of Limpopo, 2017 / Root-knot nematodes (Meloidogyne species) are the major soil-borne pests of tomato (Solanum lycorpesicum) plants. Due to the global withdrawal of effective chemical nematicides from the agrochemical markets, nematodes are difficult to control under the production systems. Currently, botanicals are being researched and developed as alternative to chemical nematicides with promising results, although they have challenge of phytotoxicity. The objective of this study was to determine the Mean Concentration Stimulation Point (MCSP) of Tickberry (Lantana camara) extracts for tomato plant-infected with M. javanica. Treatments consisted of six levels of L. camara extracts, namely, 0, 2, 4, 6, 8 and 10% per pot, which were arranged in a randomised complete block design, with ten replicates. Tomato seedlings were inoculated with 2500 second-stage juveniles (J2S) of M. javanica at five days after transplanting, with treatments applied at seven days after inoculation. At 56 days after inoculation, L. camara extracts had positive effects on plant height, stem diameter, number of leaves, number of fruits and fruit mass, contributing 65, 74, 61, 25 and 61% in total treatment variation (TTV), respectively, under greenhouse conditions. Under microplot conditions, treatments contributed 55, 85, 61, 36 and 85% in TTV of the respective plant variables. Under greenhouse it contributed 60, 35 and 77% and 29, 79 and 70% under microplot on dry shoot mass, dry root mass and galling index respectively. Treatments did not have any effects on soil pH and electrical conductivity (EC). Under greenhouse conditions, treatments contributed 88, 94 and 92% in TTV of nematode in roots, soil and final population, respectively, whereas under microplot conditions 94, 97 and 95% in
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TTV of the respective nematode stages. The derived mean concentration of L. camara extracts for tomato was 5.76 and 5.31% under microplot and greenhouse conditions, respectively. The overall sensitivity of tomato plants to L. camara extracts under microplot and greenhouse were 3 and 0, respectively. In conclusion Meloidogyne species can be managed using L. camara extracts 5.31 and 5.76% under glasshouse production and field production system respectively.
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Fine-Root Functional Traits Across the Gymnosperm PhylogenyLangguth, Jessica R. 11 December 2021 (has links)
No description available.
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AN EXPERIMENTAL STUDY OF THE INFLUENCE OF MISALIGNMENTS ON THE LOADED TRANSMISSION ERROR AND ROOT STRESSES OF HYPOID GEAR PAIRSBlettery, Hugo January 2016 (has links)
No description available.
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Klinische und mikrobiologische Variablen bei Einsatz verschiedener Spüllösungen während des Scaling und Root Planings im Verlauf von 12 MonatenKrück, Carlos 21 June 2011 (has links)
Ziel dieser Studie war es, die längerfristige Auswirkung der Taschenspül-lösungen 0,9% NaCl (n=18), 0,12% Chlorhexidindigluconat (n=17) und Povidon-Jod (n=16) auf klinische und mikrobiologische Variablen bei 51 Patienten mit generalisierter moderater chronischer Parodontitis während des full mouth SRP zu untersuchen. Die subgingivale Irrigation der behandelten parodontalen Taschen wurde randomisiert durchgeführt. Vor SRP, nach 3 und nach 12 Monaten erfolgte die klinische Diagnostik (PD,
BOP, AL) mittels 6-Punktmessung. Subgingivaler Biofilm wurde an vier Zähnen mit einer Sondierungstiefe von 4-6 mm zur quantitativen mikrobiologischen real time PCR-Analyse von Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia und Treponema denticola entnommen.
PD nahm in allen Gruppen signifikant ab (p<0,001–p=0,002), CHX wirkte dabei nach 3 Monaten signifikant besser als NaCl (p=0,041). AL war in allen Gruppen nach 3 Monaten signifikant verbessert, nach 12 Monaten nur in der CHX- und Povidon-Jod-Gruppe (p<0,001–p=0,044) ohne Unterschiede zwischen den Gruppen. BOP war bei allen signifikant verringert (p<0,001–p=0,002) ohne Unterschiede zwischen den
Gruppen. Die Gesamtkeimzahl von A.a. (p=0,045) und von P.g. (p=0,002) war nach 12 Monaten und von T.f. nach 3 (p=0,021) und zwischen 3 und 12 Monaten (p=0,011) für Povidon-Jod signifikant reduziert. Für P.g. wurde eine signifikante Reduktion der positiven Proben in der Povidon-Jod-Gruppe nach 3 (p=0,017) und nach 12 Monaten (p=0,001) festgestellt. Bei T.d. lag keine signifikante Veränderung vor. Signifikante
Unterschiede lagen zur Baseline-Untersuchung bei A.a. zwischen der CHX- und der Povidon-Jod-Gruppe (p=0,038) und bei P.g. zwischen der Povidon-Jod- und der CHX- bzw. NaCl-Gruppe vor (p<0,001), dies ließ sich im weiteren Verlauf nicht verfolgen. Die angewandte Therapie hat, unabhängig von der Spüllösung, klinisch zum Erfolg geführt. Bei Betrachtung der Wirksamkeit gegen die parodontopathogenen Bakterien A.a., P.g. und T.f. scheint Povidon-Jod überlegen zu sein, jedoch nur bei
Betrachtung der Unterschiede innerhalb der Gruppen, nicht bei deren Vergleich.
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Study on the mechanisms of rhizosphere priming effects induced by root exudates in a temperate broad-leaved forest / 温帯広葉樹林における根滲出物の根圏プライミング効果のメカニズム研究Sun, Lijuan 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21150号 / 農博第2276号 / 新制||農||1059(附属図書館) / 学位論文||H30||N5124(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 北山 兼弘, 教授 小杉 緑子, 教授 本田 与一 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM
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Primary Afferent Projections From Dorsal and Ventral Roots to Autonomic Preganglionic Neurons in the Cat Sacral Spinal Cord: Light and Electron Microscopic ObservationsMawe, G. M., Bresnahan, J. C., Beattie, M. S. 02 January 1984 (has links)
HRP applied to cut dorsal and ventral roots of the cat sacral spinal cord labeled afferent axons with swellings in close apposition to labeled preganglionic neurons (PGNs) in the sacral parasympathetic nucleus. Electron microscopy allowed characterization of synaptic contacts between afferents and PGNs. The results suggest that both the dorsal and ventral root afferents can directly activate autonomic preganglionic neurons.
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An in-vitro comparison of the microleakage of RealSeal/Resilon and RealSeal Self-Etch/Resilon root canal obturation systemIqbal, Haris January 2011 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this investigation was to evaluate and compare microleakage of teeth obturated using either RealSeal/Resilon or RealSeal Self-Etch/Resilon systems. The goal was to determine whether a significant difference in microleakage exists between these two groups. To date, no study has been done comparing the microleakage of root canal systems obturated with using RealSeal/Resilon versus RealSeal SE/Resilon.
Sixty-two human, single-rooted, anterior teeth were accessed and instrumented for non-surgical root canal therapy. Teeth were randomly assigned to two experimental groups of 27 teeth each. Group I consisted of teeth obturated with the RealSeal/Resilon system, whereas Group II consisted of teeth obturated with the RealSeal SE/Resilon system. In addition, two control groups containing four teeth each served as positive and negative controls, Group (+) and Group (-), respectively. The teeth were then evaluated for microleakage using a dual-chamber microleakage model. Visual turbidity in the lower chamber denoted microleakage within the experimental groups observed for 33 days.
RealSeal SE Group II had a significantly higher proportion of samples than Real Seal Group I. Time to microleakage was also significantly lower in RealSeal SE Group II than in Real Seal Group I. No microleakage was observed in the negative control and microleakage was observed in all four samples in the positive control.
To date, this is the first study comparing the microleakage of RealSeal/Resilon and RealSeal SE/Resilon systems. The higher microleakage associated with RealSeal SE is attributed to the higher pH of the self-etch (SE) sealer in comparison with the self-etch primer of RealSeal. The self-etching potential of the sealer system is particularly critical in areas inaccessible to calcium chelating agents such as EDTA in root canal systems. Further research needs to be done to corroborate the microleakage results from this study.
The microbial leakage apparatus devised in this study, which used a selective growth medium with streptomycin, has also been validated by the results of the study. The bacterial leakage apparatus has been considered to be clinically relevant and acceptable by the Journal of Endodontics. Thus, the modified dual-chambered microleakage apparatus with a selective growth medium used in this research can be replicated easily in future microleakage studies.
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INVESTIGATIONS INTO THE USE OF TREES FOR PHYTOREMEDIATION OF PAH CONTAMINATED SOILSMUELLER, KEVIN E. 30 September 2005 (has links)
No description available.
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