Browsing by Author "Gambaseni, Charles"

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    Studies on the Biology of Phaseolus Aureus Roxb in competition with Cyperus Rotundus
    (University of Dar es Salaam, 1979) Gambaseni, Charles
    The competition between p.aureus and c. rotundus was investigated. Intact weed tubers and both aqueous and alcoholic tuber extracts did not inhibit the germination of p. aureus . c. rotundus tubers exhibited self-inhibition in germination when sown at higher densities while increase in density of p. aureus seed did not affect their own germination . In the case of both p.aureus and c.rotundus growing in pure population or in competition with each other increases in plant density generally reduced mean dry weight of the plants and of the plant components. Intra- specific competition appeared to be more important than interspecific competition. Competition between paureus and c. rotundus was characterized by a critical period of 2/3 weeks duration, this period beginning about 4 weeks after sowing the seed. p. aureus plants were observed to survive a drought treatment of more than 2 weeks after which the plants quickly wilted and finally died. During drought treatment, water saturation deficit (WSD%) increased with increase in time of droughting. Rewastering of the drougted plants quickly lowered the water saturation deficit to almost the same magnitude as that of the control. Transpiration rate was lowered with increase in droughting period, while re-watering the plants increased transpiration rate slightly. Water stress affected dry matter production more than either nutrient levels or density. Nutrients had the least affect on dry matter production.