Wild mustard (Brassica spp.) is used as an edible wild leafy vegetable by indigenous people
in South Africa. The potential of wild leafy vegetables in agriculture is not well understood,
because there is generally no agronomic research on their production practices. The objective
of this study was to examine the performance of three wild mustard species (herein referred
to as I, K and M) over four cropping seasons in an intercropping system with green beans
(Phaseolus vulgaris L. cv. Imbali). The crops were grown with and without organic fertiliser
under dryland conditions at two sites (The University of KwaZulu-Natal Research Farm,
Ukulinga and in a rural area of Umbumbulu, KwaZulu-Natal within the farmers' locality)
during autumn, winter, spring and summer of 2004 to 2005. Plant development (leaf number,
plant height and fresh biomass) during the first six weeks after sowing and seed yield were
used to determine agronomic performance of each species. Nutrient status of the rhizosphere
soil was determined at 42 days after sowing for each species to determine what effect
growing the species would have on mineral availability. Wild mustard production
significantly (P < 0.01) performed better at Ukulinga than Umbumbulu. Polyculture was
beneficial for wild mustard leaf accumulation and green bean production as determined by
land equivalent ratios greater than one for all species combinations, regardless of fertiliser
application. Cool environmental conditions occurring in autumn and spring were more
favourable (P < 0.05) for wild mustard and green bean biomass accumulation than summer
and winter conditions. However, wild mustard seed yield was highest in winter compared
with autumn and spring, and there was no measurable seed production in summer. Soil
analysis results at 42 days after sowing showed an increase in P, K, Cu and Mg in the
rhizosphere of wild mustard without organic fertiliser. Polyculture improved Zn, Cu, Mn and
K in wild mustard leaf tissue. It is concluded that wild mustard can be grown as a leafy
vegetable throughout the year, but it requires cool environmental conditions to enhance seed
yield. Species M significantly yielded better biomass and seeds than species I and K during
all the seasons. However, species K performed the least in all aspects. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/4552 |
| Date | January 2005 |
| Creators | Phiri, Nathan. |
| Contributors | Modi, Albert Thembinkosi. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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