Thesis (M.Sc. (Plant protection )) --University of Limpopo, 2011 / Monsonia burkeana is widely used as a decoction for plant protection in South Africa. However, the accumulative capabilities (ACs) for essential nutrient elements and phenolic-antioxidant relationship in its organs are not documented. A study was conducted to determine whether: (1) the ACs for nutrient elements in fruit, leaf, stem and root of M. Burkeana were similar, (2) total phenolic and antioxidant contents in fruit, leaf, stem and root of M. burkeana were distributed equally, and (3) phenolic levels have an effect on accumulation of antioxidants in the four organs. Ten plants per plot, with three replicates, were harvested whole, oven-dried and separated into the four organs and then quantified for the above enlisted variables. The ACs for essential nutrient elements differed among the four organs. Generally, reproductive organs and leaves had high ACs for macro-nutrients, whereas roots had high ACs for micro-nutrients. Similarly, reproductive organs and leaves were good sources of phenolic and antioxidant compounds. Saturation factors in various organs of M. burkeana suggested that more than 90% of antioxidants were derivatives of the phenolic compounds. Optimum levels of antioxidant activities were attained at 5.39, 5.49, 4.36 and 4.13 mg/ 100 g of phenolic content in fruit, leaf, stem and root, respectively. Consequently, M. burkeana organs have the potential to provide fertiliser effect on crops, and both phenolics and antioxidants required as active ingredients for sprays used in plant protection. / the National Research Foundation,the National Department of Agriculture,Forestry and Fisheries,the National Department of Science and Technology

Call number: LD2668 .T4 1979 C5266 / Master of Science

One of the most important photosynthetic enzymes in a plant is ribulose-1,5¬bisphosphate carboxylase/oxygenase (Rubisco), which plays a key role in carbon fixation. Degradation of this enzyme leads to decreased carbon fixation and poor photosynthetic performance by the plant. It is therefore of interest to investigate possible ways of protecting this enzyme during stress conditions in order to generate plants that would perform better under extreme climates. In this study the effect of an expressed, exogenous rice cysteine proteinase inhibitor (OCI) in transformed tobacco plants on Rubisco stability/content under chilling and senescence was investigated. Results showed that there is no significant protective role for exogenous OCI on the degradation/content of Rubisco when tobacco plants were exposed to chilling. This result was found using native gel-based quantification procedures, as well as immuno-blotting, spot densitometric analysis, and a radioactive quantification assay as analysis techniques. The study, however, provided evidence for protection of Rubisco against degradation by expression of OCI under a more severe stress condition, such as senescence using native gel-based quantification procedures as detection techniques. Tobacco plants were also transformed with a newly designed vector allowing expressed OCI to be transported to the chloroplast. Failure to detect so far any OCI-¬expressing transformed plants and the idea that delay of senescence could prove beneficial to farmers by providing a more nutrient-dense crop with higher tolerance against stress-induced cell death are discussed. / Dissertation (MSc(Botany))--University of Pretoria, 2006. / Plant Science / unrestricted

Thesis(M.Sc.(Plant Protection))-- University of Limpopo,2019 / Previously, cucurbitacin-containing phytonematicides that were drench-applied in black plastic containers filled with pasteurised loam soil when placed on the soil surface had no effect on suppression of population densities of root-knot (Meloidogyne species) nematodes. The active ingredients of cucurbitacin-containing phytonematicides, namely, the cucurbitacins, had been shown to be thermophilic, with the failure of the products explained from the view of the variability induced by container-type and aboveground positioning. The view was investigated further using Nemarioc-AL and Nemafric-BL phytonematicides as influenced by container-type and positioning on growth of tomato (Solanum lycopersicum L.) plants and suppression of M. incognita population densities. Tomato cv. ′Floradade′ seedlings were transplanted into 30-cm-diameter brown pot belowground, brown pot aboveground, black pot belowground, black pot aboveground, 5 L polyethylene plastic bag belowground and 5 L polyethylene plastic bag aboveground, each containing 5-dm3 steam-pasteurised sandy loam soil amended with Hygromix at 3:1 (v/v) ratio. Seedlings were inoculated with 2000 eggs and second-stage juveniles (J2) of M. incognita race 2, with Nemarioc-AL and Nemafric-BL phytonematicides applied once 17 days after inoculation in both Experiment 1 and Experiment 2. Also, standard cultural practices were applied throughout the trial. At 56 days after inoculation, container-type and positioning had significant effects on various plant growth and essential nutrient element variables in Experiment 1 and Experiment 2, except that the six treatments did not have significant effects on nutrient elements and nematode population densities in Experiment 2. Relative to brown plastic pot belowground, treatments either increased or decreased plant growth, essential nutrient elements and nematode densities in Experiment 1, with selective similaritiesin Experiment 2. Specifically, nematode variables except for J2 in soil and total nematode population densities were significantly affected by the treatments in Experiment 2. Relative to the standard, plastic bag belowground increased J2 in soil and total population in soil by 18%. In conclusion, both container-type and positioning had effects on the efficacy of phytonematicides on plant growth, accumulation of essential nutrient elements and suppression of nematode population densities. Consequently, in trials where cucurbitacin-containing phytonematicides are conducted in microplots, brown plastic pots with the belowground positioning should be used to enhance the efficacy of the phytonematicides in stimulating plant growth and suppression of nematode population densities.

Univ., Diss.--Zugl.: Orléans, 2005.

Thesis (M.S.)--University of Delaware, 2009. / Principal faculty advisor: Robert E. Lyons, Dept. of Plant & Soil Sciences. Includes bibliographical references.

Thesis (Ph. D.)--Dept. of Botany, University of Adelaide 1976. / Volume 2 consists almost entirely of maps. Includes index of plant species. Includes bibliographical references (p. 227-242 (v. 1)).

Submitted in fulfillment of the requirements of the Master of Information and Communications Technology degree in Information Technology, Durban University of Technology, Durban, South Africa, 2017. / This dissertation reports on the original study that undertakes the development of a frugal information system to support subsistence farmers through the use of the Agricultural Production Systems Simulator (APSIM) as a support tool to assist them in optimal strategic decisions making. The field of agriculture is vast and in-depth and a number of critical factors like soil type, rainfall and temperature are involved that farmers have to take into account. Farmers persistently face the challenges of increasing and sustaining yields to meet with the populaces demand with often limited resources, which makes strategic decisions on what to plant, when to plant, where to plant and how to plant in a particular season imperative. The way in which this study attempts to solve this agricultural decision making problem is with the use of the APSIM. This technology platform provides an advanced simulation of agricultural systems that can enable subsistence farmers to simulate a number of variables ranging from plant types, soil, climate and even management interactions. This research presents a frugal web-based crop planning decision support system that subsistence farmers can take advantage with the use of the APSIM. The APSIM platform was used to run simulations for various regions with the results containing the expected level of success along with other useful information for a specified crop in the vicinity, using state of the art software platforms and tools ranging from Google Maps application programming interfaces, Microsoft’s model view controller framework, JavaScript and others. The validity of this system was tested through a number of design science methods including structural testing and illustrative scenarios, show capability of the information system. The results obtained from this evaluation show a small but powerful tool that has the capability of servicing a multitude of farmers with crop management decisions. / M

L'infusion du tourteau de graines de neem, suivie d'un lavage au méthyl-tert-butyl-éther, a été la procédure optimale pour extraire l'azadirachtine. L'importance de l'azadirachtine a été mise en relief par les bio-essais visant à évaluer la toxicité des extraits de neem contre le puceron vert du pécher. En effet, pour une même concentration en azadirachtine, les formulations NEEMAZAL®-EC, H2O/MTBE et AZT ont eu le même délai d'action sur la survie de larves de M. persicae. De plus, l'application de 30 ppm d'azadirachtine sur des feuilles de pommes de terre infectées par le PLRV a permis de réduire de 61% l'acquisition du virus par des adultes aptères. Cependant, l'ajout d'huile de neem à l'azadirachtine fut nécessaire pour obtenir une formulation capable de réduire la transmission du PVY par des adultes ailés. En revanche, aucun des traitements appliqués avec les formulations élaborées en laboratoire, même celles contenant de l'huile de neem, n'ont été capable de réduire de façon significative la transmission du PLRV, bien que ceux effectués avec le NEEMAZAL®-EC aient permis, dès 11 ppm d'azadirachtine, une réduction significative de la transmission du virus circulant.

Volume 2 consists almost entirely of maps. Includes index of plant species. Bibliography: p. 227-242 (v.1) Floristic and structural changes in native vegetation resulting from man's influence are examined in detail in 5 South Australian parks. The results permit the clear delineation and segregation of those patterns determined by man's activities, from those induced by soil and topographic features.