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Effect of
proportion of component species on the productivity of
Solanum aethiopicum and Amaranthus lividus under
intercropping
Charles K. Ssekabembe
Department of Crop Science, Makerere University. P. O.
Box 7062, Kampala, Uganda. E-mail:
cssekabembe@agric.mak.ac.ug . Tel. 0782896886 (Mobile);
Accepted 5 June, 2008 |
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In central Uganda, ‘garden egg’ (Solanum aethiopicum)
is commonly intercropped with ‘spleen amaranth’ (Amaranthus
lividus) but the productivity of this mixture is
unknown. The objective of the experiment was to determine
the yield advantage from this mixture. Treatments tested
included pure stands of Solanum aethiopicum and
Amaranthus lividus, locally called nakati and ebugga,
respectively, ‘additive mixtures’, and several ‘replacement
series’ mixtures. Generally, pure stands gave the highest
total and edible DM yields. For each species, DM yield in
mixtures was significantly higher (P<0.05) in mixtures in
which it constituted the highest proportion, that is 75:25%
Solanumi:Amaranthus replacement series mixture
in the case of S. aethiopicum, and 25:75%
mixture in the case of A. lividus.
Intercropping reduced total S. aethiopicum DM
yield by 72% in the 25:75% Solanum:Amaranthus
mixture, while A. lividus yield was reduced by
68% in the 75:25% mixture. There was high correlation
between S. aethiopicum and A.
lividus plant population and edible DM yield (r = 0.71
and 0.98, respectively).The difference in yield between pure
stand S. aethiopicum and the 75:25% Solanum:Amaranthus
mixture was not significant yet it was associated with 93 kg
ha-1 of edible DM yield of A. lividus
as a ‘bonus’ yield, equivalent to 27% of the edible DM yield
of pure stand A. lividus. Generally, the
additive mixtures gave higher S. aethiopicum
DM yield than the replacement series mixtures with less than
50% S. aethiopicum. The 37% lower edible DM
yield of S. aethiopicum in the double compared
to the single additive mixture was attributed to greater
competition against S. aethiopicum by the
double Amaranthus rows compared to the single
Amaranthus rows but the double additive mixture had
about 55% more edible Amaranthus DM yield than the
single additive. Most mixtures gave yield advantages, with
the double (47%) and single (39%) additive mixtures giving
higher yield advantages than the replacement series
mixtures. On the basis of gross returns, most mixtures were
more profitable than the pure stands.
Key words:
Garden egg (Solanum aethiopicum), spleen amaranth (Amaranthus
lividus), proportion of component species, plant
population, intercropping, yield advantage.
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