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Vachellia tortilis is a tree belonging to the family Fabaceae that inhabits high temperature and dry environments of the world. It is ecologically and economically significant amongst others of the genera Vachellia and Senegalia. It is native to Namibia and several other countries. Various parts of the V. tortilis plant are used for different therapeutic purposes both in the traditional and pharmacological settings. However, V. tortilis is vulnerable to pathogenic infection to which they lack natural resistance and little is known regarding the pathogens responsible for such infections. The aim of the study was to isolate and identify the fungal species associated with twig dieback disease in V. tortilis. Pure cultures from diseased V. tortilis were grown using potato dextrose agar (PDA) and DNA was subsequently isolated and later amplified in a PCR reaction using ITS1 and ITS4 primers. Sequencing and BLAST search revealed the identity of the isolates as; Penicillium rubefaciens, Penicillium herbarum, Trichoderma longibrachiatum and Trichoderma harzianum. Results indicated that P. herbarum was associated with disease symptoms in A. tortilis, T. longibrachiatum and T. harzianum were antagonistic fungi while the effect of P. rubefaciens on V. tortilis remained unknown. It is recommended that further investigations using Koch’s postulates should be performed on V. tortilis using the isolates.

A diverse group of soil bacteria known as plant growth promoting rhizobacteria (PGPR) is able to inhabit the area close to plant roots and exert beneficial effects on plant growth. Beneficial interactions between rhizospheric bacteria and plants provide prospects for isolating culturable PGPR that can be used as bio-fertilizers for sustainable crop production in communities that cannot easily afford chemical fertilizers. This study was conducted with the aim of isolating rhizospheric bacteria from grasses along the Kavango River and screening the bacterial isolates for plant growth promoting characteristics. The bacteria were isolated from rhizospheres of Phragmites australis, Sporobolus sp., Vetiveria nigritana, Pennisetum glaucum and Sorghum bicolor. The isolates were screened for inorganic phosphate solubilization, siderophore production and indole-3-acetic acid (IAA) production. The nitrogen-fixing capability of the bacteria was determined by screening for the presence of the nifH gene. Up to 21 isolates were obtained from P. australis, Sporobolus sp., S. bicolor, P. glaucum and V. nigritana. The genera Bacillus, Enterobacter, Kocuria, Pseudomonas and Stenotrophomonas, identified via 16S rDNA were represented in the 13 PGPR strains isolated. The isolates exhibited more than one plant growth promoting trait and they were profiled as follows: three phosphate solubilizers, four siderophore producers, eight IAA producing isolates and five nitrogen-fixers. These bacteria can be used to develop bio-fertilizer inoculants for improved soil fertility management and sustainable production of local cereals.