|dc.contributor.advisor||Cairns, A. L. P.||
|dc.creator||Liebenberg, Benjamin Christiaan.||
|dc.description||Thesis (M.Sc.Agric.)-University of Natal, Pietermaritzburg, 1997.||en
|dc.description.abstract||The use of a maize/bean intercropping system to improve land
productivity was investigated after limited land availability had
been identified (Liebenberg, 1993) as a major constraint to crop
production in the Vulindlela area of the KwaZulu-Natal province
of South Africa.
The objective of this study was to develop an intercropping
system that would: a) Give an intercrop bean yield approximately
equal to that of the sole crop yield, b) Give a maize yield
acceptable to the farmer (needed mainly for green maize). c)
Produce a land equivalent ratio (LER) greater than one.
In order to ensure high bean yields, maize dominance was reduced
by lowering the normal maize population of the intercrop by 50%
and by using a tramline row arrangement instead of evenly spaced
rows. Two bean cultivars namely Mkuzi (carioca) and Umlazi
(speckled sugar) and two maize cultivars namely Kalahari Early
Pearl (KEP) (an open pollinated cultivar) and SR 52 (a hybrid)
were used. Single trials were planted at four localities spread
over three seasons i.e. Vulindlela and Ukulinga (1992/93), Cedara
(1995/96) and Makhathini (1996). The treatments included varying
bean densities, bean planting times and maize harvesting stages.
These treatments were compared to maize and bean sole crop
High maize yields led to low bean intercrop yields. However,
there was little or no difference between sole bean yield and
intercrop bean yields associated with lower maize yields.
Intercrop maize yields were 50% of the sole maize yields at all
the sites. The mean LER's for the Vulindlela and Ukulinga trials
were 1.04 and 0.96 respectively while the mean LER's for the
Cedara and Makhathini trials were 1.34 and 1.31 respectively.
Only the latter two trials displayed significant improvements in
land productivity. Mkuzi was more affected by intercropping than
Umlazi while KEP competed less with the beans than SR 52 and gave
higher yields under less favourable growing conditions.
Yield component studies indicated that stress during the
vegetative, pod formation, and pod filling stages led to yield
reduction in the dry bean crops. Light and leaf nutrient level
studies suggested that the yield reduction resulted from
competition for nitrogen and light. There was no competition for
phosphate and potassium. The study indicates that the
intercropping system did meet the desired requirements under
conditions that are less than ideal for maize production, such
as low soil fertility, water stress and cool temperatures.||en
|dc.title||Intercropping of maize and dry beans for the Vulindlela district of KwaZulu-Natal.||en