Thesis (MScAgric)--Stellenbosch University, 1990. | ENGLISH ABSTRACT: Wheat (Triticum aestivum) is grown in monoculture in much of the winter rainfall region of the Western Cape Province of South Africa. This has led to a dramatic increase in the incidence of take-all (caused by Gaeumannomyces graminis var. tritici). In a tillage experiment on the Langgewens research farm of the Department of Agricultural Development, a close correlation was found between disease incidence following cultivation with a chisel plough, a mouldboard plough or no tillage. Cultivation with a mouldboard plough, or no tillage resulted in a low disease incidence and higher yields. | AFRIKAANSE OPSOMMING: In 'n groot gedeelte van die Winterreënstreek van Wes-Kaapland word koring (Triticum aestivum) onder monokultuurtoestande verbou. Hierdie praktyk het tot gevolg gehad dat vrotpootjie (veroorsaak deur Gaeumannomyces graminis var. tritici) die afgelope paar jaar dramaties toegeneem het. In 'n bewerkingsproef op die Langgewens-proefplaas van die Departement Landbou-Ontwikkeling is daar 'n noue verwantskap aangetref tussen vrotpootjie-voorkoms en die plasing van die vorige jaar se vrotpootjie-geïnfekteerde wortelkrone en wortels deur bewerking. Bewerking met 'n scarifier het aanleiding gegee tot betekenisvol meer vrotpootjie as in gevalle waar beitelploeg-, skaarploeg-, of geen-bewerking gedoen is. Waar skaarploeg- of geen-bewerking onder monokultuurtoestande toegepas is, is 'n lae vrotpootjie-voorkoms, met gepaardgaande goeie opbrengste, waargeneem. | Masters

Main objective of this research is to evaluate the government wheat policy in the irrigated regions of Jordan Valley and the southern desert, using a quantitative policy analysis. Wheat production under irrigation was found inefficient compared with tomato production in the Jordan Valley and with alfalfa in the southern desert of Jordan. On the other hand the DRC was found to be 0.42 for wheat produced in the Jordan Valley, which meant that wheat production in this region makes an efficient use of the domestic resources, but when the revenues of tomato in the same area were used as the shadow price of land, the DRC become 4,53, which meant that production of tomato in Jordan Valley was more efficient in the use of resources than the wheat. In the southern desert, also, the DRC's were one or less, when the cost of water (private price and social price) were estimated as 27 fils/m3 and 83.92 fils/m3, respectively. However, when the price of water was set as its municipal use rates, the DRC reached 2.85 and 2.45 for summer and winter wheat respectively, and for alfalfa it was estimated to be 1.86. The domestic wheat consumption was 575.000 t (1988), 28% of which was locally produced. Production of irrigated wheat in Jordan in the same year was 25.700 t, about 9% of the total consumption

In a blind cross over study the impact of short-term whole wheat consumption and in a prospective study the impact of long-term whole wheat consumption was measured on the non-specific immune response. Volunteers (n = 16) regularly consuming whole wheat participated in the cross over study and were divided into two groups. Each group consumed whole wheat products for 10 days and white flour products for another 10 days. Another 16 volunteers participated in the prospective study, 8 that consumed whole wheat products regularly and 8 that never consumed whole wheat. The measured immune parameters were: phagocytic capacity of PMNL, specific activity of NK cells and serum lysozyme concentration. In the cross over study no differences between the groups were detected in the activity of the NK cells and the lysozyme concentration. The phagocytic capacity of PMNL during whole wheat consumption at day 2 and 10 was significantly higher (p<0.001 and 0.05) than in the control In the prospective study no statistical significant differences between the groups were detected for the phagocytic capacity of PMNL and the activity of the NK cells. The serum lysozyme concentration showed a significantly higher value at day 0 and 4 (p<0.05) with whole wheat consumption. It was concluded that immunomodulating polysaccharides from whole wheat as part of the daily diet have no statistical significant influence on the non-specific immune response of man.

Main purpose of this research was to examine the impact of the Jordanian Government Price Policy related to wheat produced in the rainfed areas. Policy analysis matrix was used to calculate the different protection coefficients. The nominal protection coefficient on output for wheat produced by both traditional and modern technologies was (1.01), which means that the government price policy has allowed the private wheat price to be 1% higher than what it would have been without the policy. On the other hand, the nominal protection coefficient for inputs used in wheat production by both technologies was (1.06) which exceeds one, due to the 6% fees payable for import licencing. This means that the farmer is paying 6% higher costs than it would have been without the policy. The effective protection coefficient (EPC), for the two technologies, was also very close to one. The domestic resource coefficient, which measures the efficiency of the comparative advantage of a crop, was (0.23) for the traditional technology and (0.11) for the modern technology of wheat production. This result indicates that the modern technology which is applied to wheat production in the rainfed areas improved the efficiency of allocation of the domestic resources.

The genetically determined quality of wheat may be maintained or spoiled by the cultivation technique applied. An analysis was made of the effect on yield quality of various techniques /irrigation, fertilization, application of herbicides and fungicides/. N fertilization consistently increased the gluten content of wheat. The results of the top dressing experiment confirmed that divided top dressing including a 40 kg N rate at flowering significantly increased both the wet gluten content and the farinographic value. The quality-improving effect of irrigation was somewhat ambiguous. The use of herbicides had contrasting effect depending on the preparation and the extent of weed cover. The best results with respect to gluten and protein contents were given by Oxitril treatment. Fungicides have a slight indirect effect on quality. The succes of all the cultivation techniques was greatly influenced by the year effect.