Banana (Musa AAA; Cavendish sub-group) cultivar/density trials in three bioclimatic groups on the north coast of KwaZulu-Natal.
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Date
1997
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Abstract
The North Coast of KwaZulu-Natal is a relatively new banana production area, for which there
is an absence of local norms, specifically for choice of cultivar and population density. Three cooperative
split-plot banana cultivar/density trials were established in December 1991, January
1992 and February 1992 on farms at Eshowe, Nkwaleni and Mposa, respectively. These sites
represent Phillips' (1973) Bioclimatic Groups 2,10 and 1 respectively, and have widely divergent
climatic potential, ranging from cool, to warm, to hot subtropical. Each randomised trial block,
0.92 ha in extent, comprised five replications of five cultivar main plots, each of which was split
into three density sub-plots. The five cultivars planted represent those registered at the time of
planting, viz. 'Dwarf Cavendish', 'Williams', 'Grand Nain', 'Valery' and 'Chinese Cavendish'.
Sub-plots were planted at 1 666, 2 105 and 2 500 plants ha(-1) and tissue culture plants were used
to establish all three trials. The field trials were evaluated over three full cropping cycles and
culminated in October 1996.
Morphological differences such as pseudostem height and circumference, leaf length and width,
number of functional leaves at flowering and harvest, as well as phenological differences such as
monthly leaf emergence rates, emergence-to-harvest intervals and harvest cycles, were evaluated.
The yield component data comprised measurements of bunch mass, number of hands per bunch
and number, length and mass of fingers on the third hand. Productivity was expressed as tonnes
per hectare per annum (t ha(-1) an(-1). Each cultivar and density treatment was evaluated
independently. However, it was the evaluation of the cultivar/density interaction which formed
the basis of the recommendations for the three different Bioclimatic Groups.
At the relatively cool Eshowe site, 'Williams' proved to be the most productive cultivar
(471 ha(-1) an(-1) over all densities. The highest production (49.8 t ha(-1) an(-1) was achieved from a
density of 2 500 plants ha(-1), but due to lower costs per hectare, the intermediate density of 2 105
plants ha(-1) generated the highest gross margin. When the cultivar/density interaction was
evaluated, the combination producing the highest gross margin was 'Williams' at 2 105 plants ha(-1).
This substantiated the independent evaluations and is consequently the recommended
combination for Bioclimatic Group 2. However, the faster cycling of 'Chinese Cavendish' could
conceivably result in this cultivar outperforming 'Williams' in future ratoons.
At the warmer Nkwaleni site, 'Grand Nain' (57.8 t ha(-1) an(-1) proved to be the most productive
cultivar. The density of 2 500 plants ha(-1) was the most productive (64 t ha(-1) an(-1) and also
generated the highest gross margin. However, the cultivar/density interaction indicated that
'Williams' at 2 500 plants ha(-1), was the highest producing combination yielding the highest gross
margin, and is consequently the recommended combination for Bioclimatic Group 10.
At the hot Mposa site, 'Chinese Cavendish' (54.21 ha(-1) an(-1) proved to be the most productive
cultivar. The density of 2 500 plants ha(-1) outproduced (57.4 t ha(-1) an(-1) the lower densities and
also generated the highest economic returns. However, when the cultivar/density interaction was
evaluated, 'Chinese Cavendish' at the lower density of 2 105 plants ha(-1) realised the highest gross
margin and is consequently the recommended combination for Bioclimatic Group 1.
Description
Thesis (M.Sc.Agric.)-University of Natal, Pietermaritzburg, 1997.
Keywords
Bananas--KwaZulu-Natal., Bananas--Varieties., Bananas--Spacing., Theses--Horticultural science.