| Summary: | The study examined interactions between morogo plants, arbuscular mycorrhizal fungi (AMF)
and Fusarium species. Morogo refers to traditional leafy vegetables that, together with maize
porridge, are dominant staple foods in rural areas of the Limpopo Province such as the Dikgale
Demographic Surveillance Site (DDSS). Morogo plants grow either as weeds (often among
maize), occur naturally in the field or are cultivated as subsistence crops by rural communities.
Botanical species of morogo plants consumed in the DDSS were determined. Colonisation of
morogo plant roots by AMF and Fusarium species composition in the immediate soil
environment were investigated in four of eight DDSS subsistence communities, Isolated AMF
were shown to belong to the genera Acaulospora and Glomus. Twelve Fusarium species were
isolated from soil among which Fusariurn verticilliodes and Fusarium proliferaturn occurred
predominantly.
Greenhouse pot trials were conducted to examine the effect of AMF on morogo plant growth
(cowpea; Mgna unguiculata) and Fusarium proliferatum levels in soil, Interaction between
plants and AMF, as well as tripartite interactions of cowpea plants, AMF and Fusarium
proliferatum were investigated. Non-inoculated cowpea plants served as controls for the
following inoculations of cowpea in pots: (i) Fusarium proliferatum; (ii) commercial AMF from
Mycoroot (PTY) Ltd. (a mixture of selected indigenous Glomus spp referred to commercial
AMF for the purpose of this study); (iii) indigenous AMF obtained from DDSS soil (referred to
iocal AMF for the purpose of this study); (iv) commercial AMF plus Fusarium proliferatum; (v)
local AMF plus Fusariurn proliferatum.
Results showed reduced root colonization by local as well as commercial AMF when Fusarium
proliferatum were present. Local AMF significantly enhanced cowpea growth while commercial
AMF apparently reduced the level of Fusarium proliferatum in the rhizosphere and surrounding
soil. Results suggest that AMF may have potential as biological growth enhancers and
bioprotective agents against Fusarium proliferatum. === Thesis (M. Environmental Science (Water Science))--North-West University, Potchefstroom Campus, 2007.
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