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Pollination
and yield responses of cowpea (Vigna unguiculata L.
Walp.) to the foraging activity of Apis mellifera
adansonii (Hymenoptera: Apidae) at Ngaoundéré (Cameroon)
Fernand-Nestor
Tchuenguem Fohouo, Albert Ngakou* and Beaudelaire Stéphanie
Kengni
University of Ngaoundéré, Faculty of Science, Department of
Biological Sciences, P.O. Box 454 Ngaoundéré, Cameroon.
*Corresponding author. E-mail:
albgak@yahoo.fr.
Accepted
20 January, 2009 |
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To determine the apicultural value of Vigna unguiculata
(L.) Walp. (Fabaceae) and evaluate the Apis
mellifera adansonii Latreille (Hymenoptera: Apidae)
activity on its pod and seed yields, the bee foraging and
pollinating activities were studied in Ngaoundéré. The
experiment was carried out within the University of
Ngaoundéré Campus on 210 flowers differentiated in two lots,
based on the protection/or not of plant inflorescences
against insect visits. The bee’s seasonal rhythm of
activity, its foraging behaviour on flowers, the
fructification rate, the number and dry weight of seeds/pod,
the percentage of normal seeds/pod, and the pod length were
evaluated. Results show that A. m. adansonii foraged
on plants throughout the whole blooming period. Worker bees
intensively and preferably harvested nectar. The greatest
mean number of workers foraging simultaneously was 500 per
1000 flowers. The mean foraging speed was 8.67 flowers/min.
These findings allow the classification of V. unguiculata
as a highly nectariferous bee plant. The number and dry
weight of seed/pod, the pod length and the percentage of
normal seeds/pod from unprotected flowers were significantly
higher than those of flowers protected from insects. The
fructification rates were 62 and 48%, while the percentages
of healthly seeds were 97.61 and 76.17%, respectively in
unprotected and protected inflorescences. The installation
of A. m. adansonii colonies close to V.
unguiculata field could be recommended to improve its
pods and seeds production in the region.
Key words:
Apis mellifera adansonii,
Vigna unguiculata, bee plant, foraging, pollination,
increased yield.
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