Theses

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A long essay or dissertation or thesis involving personal research, written by postgraduates of University of Ghana for a university degree.

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    Laboratory Studies on Forest and Savannah Populations of Bulinus (Physopsis) Globosus in Ghana
    (University of Ghana, 1972-11) Kuma, E.E.
    Studies on laboratory colonies of Bulinus globosus from forest, savannah and transition zones have been carried out. The morphology, growth and reproduction of such snails have been oompared. Crosses between single snails from the three zones have been carried out and the effect of overcrowding on growth and reproduction has been investigated. Certain aspects of their behaviour such as mating, pattern of oviposition, feeding and distribution in a culture dish have been described. The effect of temperature on the snails' oviposition has a1so been studied. Finally, the problem of desiccation has been looked at end the esterase fractions of' the snails have been compared.. \
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    Some Physiological Effects of Chlormequat (2—Chlercethyl Trimethylammoniuni Chloride) Oh The Growth of Shallots. (Allium Aacalenicum L.)
    (University of Ghana, 1973-04) Quashie-Sam, J. S.; Sinnadurai, S.
    Some physiological effects of chlormequat on the growth of shallots (Allium asealonicum L.) were studied. Chlormequat at 0, 2500 and 5000ppm was sprayed it 7, 21, and 35 days after planting. Chlormequat had no effect on the growth in fresh or dry weight, leaf number, leaf length, leaf diameter and net assimilation rate of shallots but increased the leaf area index of shallot plants. In a second experiment bulbs of plants sprayed with chlormequat were planted to determine residual effects of the chemical. The plants produced from treated bulbs compared with control plants exhibited increases in rate of sprouting, growth in fresh or dry weight, leaf number and leaf area index but leaf length and leaf diameter were not affected. Chlormequat had little direct effect on shallots but planting material obtained from plants treated with chlormequat may be useful to increase yields of shallots.
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    The Effects of Potassium, Calciumand Irrigation Treatments on theYield and Quality of Tomatoes (Lycopersicon Esculentum Mill)
    (University of Ghana, 1974-07) Amable, R.A.; Hume, D.J.; University of Ghana, College of Basic and Applied Sciences, School of Agriculture, Department of Crop Science
    Five experiments were conducted to investigate the effects of potassium (K), calcium (Ca), and irrigation on yield and quality in tomatoes. K at 3 g/plant in a box containing 2.7 m^ of soil decreased the pH and incidence of blotchy ripening of the fruit, and increased the incidence of cracking and the K content of the fruit juice. Four sprays of 0.2% CaCl2 increased the total weight yield of fruit. The average fruit weight increased at the higher irrigation frequency but the number of flowers, fruit number, soluble solids content, titratable acidity, blotchy ripening, and the K content of juice decreased. K at 122 and 244 kg/ha in the field decreased pH and increased the titratable acidity and K content of the fruit. Ca and irrigation treatments had no main effects on yield and quality but there was a three-way interaction among treatments, on pH and titratable acidity. Irrigation decreased the K content of the juice. The effects of ten treatments, being a control and combinations of three rates (6 1 , 1 2 2 , and 244 kg/ha) and times of application ( 1 week, 3 weeks and a split dose 1 and 3 weeks after transplanting) of K were studied in two experiments. Treatments influenced soluble solids content and leaf K content in one experiment only. Three irrigation frequencies (irrigated every 2 days, every 4 and 6 days, and every 6 days) were imposed on tomato plants grown in boxes. Frequent irrigation increased average fruit weight and the incidence of severe blotchy ripening, and decreased the soluble solids content and titratable acidity of the fruit. K and Ca treatments had little influence on yield and blossom-end rot (BER). High K levels, however, affected quality by increasing fruit acidity and promoting uniform pericarp colouration. Increasing irrigation frequencies promoted larger fruit size but decreased fruit soluble solids content and acidity.