Browsing by Author "Adjaloo, Michael Kodwo"

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    Foraging strategies and some morphometric characteristics of the African Honeybee (Apis mellifera adansonii L) in the humid forest environment
    (1991-05-08) Adjaloo, Michael Kodwo
    The foraging strategies and some important morphometric characters of the African honeybee, Apis iuellifera adansonii were studied in detail in humid forest environment with the view to contributing to a full appreciation of the relative importance of this race in crop pollination and honey production. Twenty-four plant species were identified in three study sites as melliferous plant species. Most of them grow together and flower sequentially; their flowering seasons are sharply defined except for few of them which show some overlap. Some of the plant species provide nectar and pollen while others provide only pollen. The one hour production rates and sugar concentration of field populations were measured to determine diurnal pattern and concentration of nectar. All the plant species had similar diurnal patterns of nectar secretion but differed in nectar standing crop. The sugar concentration of nectar in more open corollas proved much more variable through the day than the concentration in the nectar of the partially or totally concealed nectaries. The foraging pattern of A. m. adansonii on the plant species was analysed, particularly in relation to weather. The results indicated that A.m. adansonii did not differ from other races of honeybee in its response to changes in weather conditions. Its numbers foraging were significantly affected by temperature, and relative humidity. Wet and cloudy conditions also reduced greatly its foraging activity. The relative abundance of A. m. adansonii on the melliferous plant species may partly be influenced by weather conditions. Sixteen morphometric characters of the bee were measured to determine whether any differences exist between populations found in the same ecological zone. The results indicated that the populations sampled were remarkably similar in all these characters. The proboscis which was relatively longer than that of the North African race, enhanced the feeding of A. m. adansonii on nectar in the melliferous flowering plants with exposed or concealed nectaries.
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    Pollination ecology of upper amazon Cocoa and breeding substrates of Cocoa pollinators in the Ejisu-Juabeng District of the Ashanti Region, Ghana
    (2015-02-23) Adjaloo, Michael Kodwo
    Cocoa plays important role in the economy of Ghana as it is the second foreign exchange earner after gold. Lives of 800,000 farmers and their families depend on it. Although it has enjoyed a consistent growth Ghana’s cocoa yields per hectare are still low by international standards. This is probably because cocoa pollination which has for a very long time been relegated to the background in the scheme of cocoa production. The study was undertaken at Kubease in the Ejisu-Juabeng district using ten farmer managed farms around the Bobiri Forest. It involved a study of the ecological importance of floral phenology of the Amazon cocoa which forms about 58% of cocoa varieties in Ghana; a survey of insects in the cocoa ecosystem to establish their pollinator status; the relative importance of the breeding substrates in the cocoa ecosystem was also investigated; and the contribution of natural pollination to cocoa production. Results indicated that cocoa trees exhibited seasonally-related phenological patterns of flowering and fruit-set involving overlapping cycles under both intrinsic and extrinsic control. Significant (P<0.001) differences in the monthly floral production existed between the study farms. Optimum floral production occurred at temperature 22.5 oC, light intensity 91.8 Fc, and rainfall of 141.1 mm per month; however, rainfall could be the most critical factor in the floral phenology. Flower stability was affected by seaons and pollination. 2721 insects belonging to 36 species and 7 orders found in the ten farm plots. About 52.81% did not visit the cocoa trees; 10.4% insects were found on the cocoa trees. The ceratopogonids visited (F1, 30 = 28.79, P <0.05) more than other insects. Only midges could carry 60.1 ± 13 pollen. Population of midges was significantly (F = 0.65, P<0.05) greater under rotten banana pseudostem than the other substrates. There were significant diferences between the number of seeds of naturally pollinated and that of artificially pollinated fruits of small size pods (P< 0.04), medium size pods (P< 0.01) and the large sized pods (P<0.01). The study therefore demonstrated that cocoa has a specialised pollination mechanism, in which pollinators belong to just one pollinator class. Rotten banana pseudo stem preferred substrate implying that it might have provided a more condusive breeding microhabitat for the ceratopogonids. Natural pollination could contribute to cocoa productivity.