Wild mustard is an indigenous leafy vegetable. Its use is limited by a lack of knowledge of its agronomy. However, it is a rich source of nutrients and other minerals. Nowadays, the use of indigenous crops has been replaced by exotic crops. Climate change is affecting agricultural productivity. South Africa is a water scarce country with uneven rainfall distribution. Therefore, studies on water stress effects on plant growth were promoted by the Water Research Commission and the University of KwaZulu-Natal to understand plant responses to water stress for commercial and subsistence farming. The objective of the study was to characterise local wild mustard cultivars morphologically and physiologically with respect to production, and for the purposes of identifying their drought tolerance. Three experiments were conducted at the University of KwaZulu-Natal in order to evaluate the responses of local wild mustard cultivars to water stress. Seeds of wild mustard cultivars were characterised according to seed coat colour. Seed quality was determined by a standard germination test. Vigour was then tested using electrolyte conductivity. Seeds were sown in seedling trays under two water regimes of 25% field capacity (FC) and 75% (FC) on pine bark growing media. The experiment was terminated at 21 days when root and shoot lengths were measured. The effect of water stress on protein content and seedling growth parameters was determined. Soil was collected from the University of KwaZulu-Natal Research Farm for a pot trial. Seeds of wild mustard were sown in 81 pots, each filled with 2 kg of soil, under three water regimes (25% FC, 50% FC and 75% FC). Pots were maintained at the corresponding field capacity level by re-weighing the pots, three times a week. Measurements of plant height and leaf number were recorded weekly. The experiment was terminated at the flowering stage. At the end of the experiment, plant growth parameters (plant height, leaf area and number, dry and fresh mass) were measured in order to evaluate the effects of water stress at the vegetative stage. A field trial was conducted at the University of KwaZulu-Natal Ukulinga Research Farm in Pietermaritzburg. The experiment was conducted during the winter and spring of 2009. A completely randomised design was used for non-irrigated and irrigated (25 mm/week) trials. Emergence was measured as well as plant height and leaf number. Plant growth parameters were also measured at the end of the experiment. Leaf samples were taken for proline determination. There was a significant interaction (p<0.05) between seed colour, landraces and days to germinate with respect to germination capacity. Isaha and Masihlalisane landraces showed higher germination percentages than Kwayimba. There was also a significant interaction (p<0.05) between landraces and seed colour with respect to electrolyte conductivity. Lighter seeds of wild mustard landraces showed higher solute leakage. Isaha and Masihlalisane had higher solute leakage than Kwayimba. Significant interactions (p<0.05) between landraces and field capacity with respect to emergence, leaf number, root and shoot length and total proteins were also observed. Isaha and Masihlalisane showed higher emergence than Kwayimba. Leaf number was reduced for all landraces under water stress. Total protein content was high in black seeded landraces under water stress. There was a significant interaction (p<0.05) between landraces and field capacity with respect to seedling fresh and dry masses. Under moderate water stress conditions, Isaha and Masihlalisane showed increased biomass accumulation. There were highly significant differences (P<0.001) in plant height, leaf area, fresh and dry mass with respect to planting date. Plants performed significantly (p<0.05) better in spring than in winter. Isaha and Masihlalisane performed significantly (p<0.05) better than Kwayimba. There was a highly significant interaction (p<0.001) between landrace and irrigation treatments with respect to proline accumulation. Under water stress, Kwayimba black seeded landrace accumulated more proline. It is concluded that light-coloured seeds of wild mustard landraces were associated with good seed quality. Masihlalisane brown seeds have good early seedling establishment. Kwayimba black seeds showed tolerance to water stress through accumulation of proteins. Isaha and Masihlalisane showed an increase in biomass accumulation under moderate water stress. Water stress tolerance in some of wild mustard landraces was negatively correlated with proline accumulation. Masihlalisane brown type can grow well, with good yields, under water stress. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

No description available.

No description available.

From 1939 to 1942 Canada, allied to the United Kingdom, prepared to defend itself against chemical attack by Nazi Germany. The Canadian preparations represented one of Canadas many contributions to the cause of the British Commonwealth, and may have been used as one method to counter British requests for additional ground troops. After the Japanese attack at Pearl Harbor, Canada became part of an alliance with the United States and the United Kingdom. Canadian chemical warfare preparations went from defensive to offensive following the attack on Pearl Harbor and the entry of the United States into the war. The chemical warfare preparations included preparation and testing of toxic gases and smokes, smoke screening and flame weapons.<p> One of the most important Canadian contributions to the alliance was the establishment of the Suffield Field Experimental Station in Alberta. This base was particularly useful in carrying out chemical weapon trials, during which approximately 2000 Canadian citizens and soldiers were exposed to toxic gases. At the beginning of the war chemical warfare volunteers were completely covered in protective clothing except for a patch to allow for controlled chemical burns. But by 1942 Suffield staff was given permission to rewrite the regulations for the trials, and volunteers often received significant chemical injuries, including to the eyes. It would appear that the full body of knowledge available to the wartime scientists, especially information relevant to the long-term health outcomes of exposure to vesicant agents, was not applied in the conduct of the human experimentation.

From 1939 to 1942 Canada, allied to the United Kingdom, prepared to defend itself against chemical attack by Nazi Germany. The Canadian preparations represented one of Canadas many contributions to the cause of the British Commonwealth, and may have been used as one method to counter British requests for additional ground troops. After the Japanese attack at Pearl Harbor, Canada became part of an alliance with the United States and the United Kingdom. Canadian chemical warfare preparations went from defensive to offensive following the attack on Pearl Harbor and the entry of the United States into the war. The chemical warfare preparations included preparation and testing of toxic gases and smokes, smoke screening and flame weapons.<p> One of the most important Canadian contributions to the alliance was the establishment of the Suffield Field Experimental Station in Alberta. This base was particularly useful in carrying out chemical weapon trials, during which approximately 2000 Canadian citizens and soldiers were exposed to toxic gases. At the beginning of the war chemical warfare volunteers were completely covered in protective clothing except for a patch to allow for controlled chemical burns. But by 1942 Suffield staff was given permission to rewrite the regulations for the trials, and volunteers often received significant chemical injuries, including to the eyes. It would appear that the full body of knowledge available to the wartime scientists, especially information relevant to the long-term health outcomes of exposure to vesicant agents, was not applied in the conduct of the human experimentation.

The mechanisms that allow invasive species to flourish in novel habitats are poorly understood. A. petiolata (Alliaria petiolata) is an invader of North American forest edge and understory communities. A. petiolata’s success may result from high competitive ability due to its suppression of mycorrhizal fungi used by other species. In a greenhouse experiment, I grew 27 target species in the presence and absence of A.petiolata in soil with and without a history of A. petiolata. I found that soil with a history of A. petiolata had depleted plant available nitrogen and reduced mycorrhizal fungal colonization of target species. A. petiolata competition suppressed the growth of target species less in soils with than without A. petiolata history. Furthermore, I found that tall plants with finer roots more effectively suppressed the growth of A. petiolata. My results suggest that soil feedback effects do not improve A. petiolata’s competitive ability and are unlikely to contribute to A. petiolata invasion.

Para-hydroxybenzyl isothiocyanate (p-HBIT) formed in yellow mustard following hydrolysis of the glucosinolate, sinalbin, is a natural antimicrobial agent. p-HBIT is not dependably available commercially, and a small amount was synthesized for use in beaker sausage fermentations. For these trials stabilized p-HBIT was used in dry sausage meat batter to reduce the viability of inoculated Escherichia coli O157:H7. A >4 log CFU/g reduction of E. coli O157:H7 was achieved in the beaker sausage containing p-HBIT. For sensory evaluation of fermented sausages containing ≤ 4% (w/w) yellow mustard powder, consumer preference tests were done. Deodorized (deheated) yellow mustard was added at 1,2,3 and 4% (w/w) to dry-fermented sausage and it was found that 3% and 4% mustard negatively affected the flavour, texture and overall acceptability of the fermented sausage. Dry-fermented sausage containing 1% and 2% mustard had a slight change in flavour, texture and overall acceptability.

No description available.

No description available.

Para-hydroxybenzyl isothiocyanate (p-HBIT) formed in yellow mustard following hydrolysis of the glucosinolate, sinalbin, is a natural antimicrobial agent. p-HBIT is not dependably available commercially, and a small amount was synthesized for use in beaker sausage fermentations. For these trials stabilized p-HBIT was used in dry sausage meat batter to reduce the viability of inoculated Escherichia coli O157:H7. A >4 log CFU/g reduction of E. coli O157:H7 was achieved in the beaker sausage containing p-HBIT. For sensory evaluation of fermented sausages containing ≤ 4% (w/w) yellow mustard powder, consumer preference tests were done. Deodorized (deheated) yellow mustard was added at 1,2,3 and 4% (w/w) to dry-fermented sausage and it was found that 3% and 4% mustard negatively affected the flavour, texture and overall acceptability of the fermented sausage. Dry-fermented sausage containing 1% and 2% mustard had a slight change in flavour, texture and overall acceptability.