Grana
ISSN: 0017-3134 (Print) 1651-2049 (Online) Journal homepage: https://www.tandfonline.com/loi/sgra20
Major plants foraged by bees for honey production
in Ghana: mapping of bee floral sources for the
development of the apicultural industry
Emmanuel LetsyoEMMANUEL LETSYO & Gabriel AmekaGABRIEL AMEKA
To cite this article: Emmanuel LetsyoEMMANUEL LETSYO & Gabriel AmekaGABRIEL
AMEKA (2019) Major plants foraged by bees for honey production in Ghana: mapping of bee
floral sources for the development of the apicultural industry, Grana, 58:6, 472-482, DOI:
10.1080/00173134.2019.1629622
To link to this article:  https://doi.org/10.1080/00173134.2019.1629622
Published online: 29 Jul 2019.
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Grana, 2019
Vol. 58, No. 6, 472–482, https://doi.org/10.1080/00173134.2019.1629622
Major plants foraged by bees for honey production in Ghana: mapping
of bee floral sources for the development of the apicultural industry
EMMANUEL LETSYO1 & GABRIEL AMEKA2
1Department of Food Science and Technology, Ho Technical University, Ho, Ghana, 2Department of Plant and
Environmental Biology, University of Ghana, Accra, Ghana
Abstract
Honey is increasingly being used as a food supplement and to treat various diseases and disorders in Ghana. Information
on floral nectar preferences of foraging honeybees is, therefore, imperative to increase production to keep pace with
demand. However, in Ghana, these floral nectar preferences are yet to be investigated and identified. This study was
conducted to determine bee forage sources in the three main agro-ecological honey-producing zones of Ghana. Forty-eight
unblended honey samples sourced from beekeepers were analysed. Pollen spectra of the honey samples revealed 27
different pollen types of which eight were identified to family level, while 15 and four were at the level of genus and
species, respectively. The results also showed that, in general, 48% of the analysed samples were unifloral honeys with the
most important pollen types coming from Sapotaceae/Meliaceae, Anacardiaceae and Burkea africana. Combretaceae,
Sapotaceae/Meliaceae and Anacardiaceae, as well as Lannea-type and Burkea africana were found to be the most frequent
(with occurrence greater than 50%) sources of nectar utilised by bees to produce honey. The predominant pollen sources
of the honeys in the three main apicultural zones of the country were Sapotaceae/Meliaceae and Anacardiaceae (Forest
zone), Sapotaceae/Meliaceae and Lannea-type (Savannah–Forest transition zone) and Sapotaceae/Meliaceae, Anacardia-
ceae and Gynandropsis gynandra (Savannah zones). Identification of the major bee floral sources can be used as a guide by
beekeepers in the location of their apiaries as well as reforesting disturbed sites with these plants to act as sources of bee
forage.
Keywords: Honeybee, apiculture, melissopalynopology, floral source, pollen analysis, Ghana
Honey serves as a natural sweetener which is used as a specific plant species (Schulz & Lueke 1994).
a food supplement in beverages for infants and Hence, pollen analysis of a honey is an indispensable
adults, as well as to treat various human diseases tool for the identification of plant preferences of bees
(Al-Jabri 2005). In addition, it is used as flavouring by providing, among other things, relevant informa-
agent in bakery and as a source of sugar in confec- tion about the pollen sources of an area which in turn
tionery. As a result, the demand for honey in Ghana helps to determine the geographical and botanical
has been increasing over the past few years. origin of honey (Louveaux et al. 1978; von der Ohe
Honeybees collect nectar and pollen from different et al. 2004). This method is based on the fact that
flowering plants for their survival. Whereas nectar is natural honey contains components (nectar and pol-
used for the production of honey which provides the len) which are present in the floral sources foraged by
colony’s primary source of carbohydrates (Winston the bees (Louveaux et al. 1978; von der Ohe et al.
1991), pollen grains, which are collected during the 2004). By correlating pollen with nectar sources, the
bees forage for nectar, are used as the primary source floral source of the honeys can be identified and this
of protein (Brodschneider & Crailsheim 2010). The information used by beekeepers in order to efficiently
dominance of a particular pollen in a honey is com- and profitably manage apiaries so as to increase honey
monly used to signify the preferences of bees for production. Pollen analysis has previously been used
Correspondence: Emmanuel Letsyo, Department of Food Science and Technology, Ho Technical University, P.O Box HP 217, Ho, Ghana. E-mail:
rebise@yahoo.co.uk
(Received 9 July 2018; accepted 17 April 2019)
© 2019 Collegium Palynologicum Scandinavicum
Plants foraged by bees for honey in Ghana 473
to determine the quality (i.e. to ascertain whether and hence vegetation variation which are congenial
honeys for both the domestic and foreign markets are for beekeeping and honey production. However,
adulterated) (Kerkvliet et al. 1995) and floral origins three of these zones (i.e. Savannah, Savannah–Forest
of honey (von der Ohe et al. 2004). In spite of this, transition and Forest zones) are particularly known
most methods used to understand the foraging prefer- for honey production (Letsyo et al. 2017). In spite of
ences of bees are based on direct field observations the country’s potential to produce honey, commercial
and/or surveys by the beekeepers, and video monitor- beekeeping is relatively underdeveloped as very little
ing (Selva-Singh et al. 2011). However, melissopaly- is known about bee floral sources and their contribu-
nology, which is the study of pollen contained in tion to apicultural activities. In fact, our review of the
honey, has been found to give a true picture of the literature revealed that melissopalynological study is
honeybee flora (Admasu & Debissa 1996). yet to be comprehensively carried out on honeys from
In Ghana, there are six tropical agro-ecological Ghana even though several similar studies have been
zones (Figure 1) with peculiar climatic conditions, reported in other West African countries such as
Figure 1. Map of Ghana showing the three major honey producing agro-ecological zones: Savannah, Savannah–Forest transition and
Forest zones.
474 E. Letsyo and G. Ameka
Nigeria (Ige & Obasanmi 2014), Benin (Azonwade Glycerol Gelatine TM Merck 1.09242.0100) coated
et al. 2017), and other parts of the globe (Silici & cover slip (von der Ohe et al. 2004).
Gökceoglu 2007; Salonen et al. 2009; Luz & Barth To determine the pollen spectra of the honey sam-
2012; Sahney et al. 2016). The only melissopalyno- ples, pollen grains were identified, if possible, down
logical/pollen analyses performed on Ghanaian hon- to genus or species level using a light microscope at
eys were focused on frequently occurring a magnification of 1000 × (von der Ohe et al. 2004).
pyrrolizidine alkaloid producing plants such as Chro- Identification of pollen grains was made with the help
molaena odorata (L.) R.M.King et H.Rob., Eupator- of reference slides and relevant literature. For the
ium spp. and Ageratum spp. (Letsyo et al. 2017). determination of percentages (relative frequency) of
Identification of the potential flora sources of honey- nectariferous species, a total of 500 pollen were
bees is necessary in selecting suitable sites for bee- counted for each slide and classified, according to
keeping in order to increase honey production, which their percentages, as predominant/unifloral (> 45%
is vital for sustaining the growth of the honey indus- of the counted pollen grains), secondary (16–45%),
try. This study, therefore, presents, for the first time, important minor (3–15%), and minor (< 3%) pollen
and to the best of our knowledge, the detailed find- classes (Louveaux et al. 1978).
ings of melissopalynological analysis of Ghanaian
honeys, particularly those from the three main agro- i:e:
ecological honey producing zones of the country. Number of pollen type counted% Frequency ¼  100
Total number of pollens counted ð500Þ
Also, in order to establish the frequency distribution
Material and methods
classes of pollen types in the honey samples, we
Study area followed the classification of Jones and Bryant
(1996): very frequent (> 50%), frequent (20–50%),
There are six agro-ecological zones in Ghana: Sudan
infrequent (10–20%) and rare (< 10%). Frequency
Savannah, Guinea Savannah, Savannah–Forest transi- of occurrence was calculated by dividing the sum of
tion zone, Deciduous Forest zone, Rain Forest zone
one pollen type by the total number of samples and
and Coastal Savannah (Figure 1). However, honey
then multiplying the quotient by 100 (von der Ohe
samples were collected in only three of these zones et al. 2004).
(i.e. Savannah, Savannah–Forest transition and Decid-
uous Forest zones). Whereas the Savannah zones have i:e: % Frequency distribution=occurrence
uni-model tropical rainfall pattern with the vegetation Number of occurrence of each pollen type
generally described as grassland with scattered indivi- ¼ ð Þ  100Total number of samples 48
dual trees, Savannah–Forest transition and Deciduous
Forest zones however have bi-modal equatorial rainfall The raw pollen data was processed using the Micro-
pattern which are characterised by scattered to dense soft Office Excel 2013.
green forest. This rainfall pattern allows for two annual
growing seasons (i.e.major andminor growing seasons)
compared with the pattern of the Savannah zones Results
which allow for only one growing season. Pollen spectra of 48 honey samples collected from three
agro-ecological zones of the country revealed a total of
217 pollens with much fewer unique pollen types (27)
Sampling and pollen analysis of honey
belonging to eight families: Anacardiaceae, Betulaceae,
Forty-eight unblended honey samples, collected Bombacaceae, Combretaceae, Meliaceae, Myrtaceae,
from three main apicultural zones of Ghana between Poaceae and Sapotaceae/Meliaceae; 15 genera: Afzelia
March and April, 2015, were subjected to a detailed spp., Ageratum-type, Ceiba spp. Combretum-type, Elaeis
melissopalynological analysis according to the spp., Eupatorium-type., Eupatorium/Ageratum-type,
method of von der Ohe et al. (2004) but with Fagara-type, Grewia spp., Helianthus-type., Helianthus/
some modification. Briefly, 10 g of honey was dis- Bidens-type, Lannea-type, Parkia-type, Senna-type and
solved in 20 mL of distilled water (20–40 °C) and Uapaca-type; and four species:Burkea africana (Hook),
centrifuged (10 min at 1000 g) (× 2) and decanted Chromolaena odorata, Gynandropsis gynandra (L.) Briq.
(× 2) to yield sediment. The entire sediment was andMimosa pudica L. (Figure 2, Table I). Pollen spec-
transferred onto a microscopic slide on a heating tra also revealed 23 (48%) of the honey samples to be
plate (≤ 40 °C) and subsequently mounted with unifloral while 25 (52%) were multifloral. The uni-
glycerine-jelly (mounting medium; Kaiser’s floral/predominant honeys (i.e. > 45%) were charac-
Plants foraged by bees for honey in Ghana 475
Figure 2. Light microscopy micrographs of some honey samples showing pollen grains. A–F, H, I, K, L. Chromolaena odorata.
G. Anacardiaceae. J. Elaeis spp. Scale bars – 10 µm.
476 E. Letsyo and G. Ameka
Table I. Pollen analysis of 48 honey samples together with their agro-ecological sources and percentage pollen content.
Floral
typea
(i.e. unifloral
or
Sample Percentage pollen content Predominant multifloral
code Origin Source (pollen count, n = 500) pollen typea honey)
G01 Nkwanta, Savannah 28% Anacardiaceae, 25% Combretaceae, 11% Fagara- — Multifloral
Ghana type, 5% Poaceae, 3% Ceiba spp., 3% Chromolaena
odorata,
3% Helianthus-type
G02 Sokodẻ, Savannah 38% Burkea africana, 22% Combretaceae, 12% — Multifloral
Togo Sapotaceae/Meliaceae,
5% Anacardiaceae
G03 Odoben, Forest 50% Meliaceae, 15% Uapaca spp., 10% Betulaceae, 5% 50% Meliaceae Unifloral
Ghana Anacardiaceae,
2% Helianthus-type/Bidens-type,
0.3% Eupatorium-type/Ageratum-type
G04 Benin Savannah 61% Sapotaceae/Meliaceae, 11% Anacardiaceae, 8% 61% Sapotaceae/ Unifloral
Myrtaceae, Meliaceae
5% Combretaceae, 3% Helianthus-type/Bidens-type, 1%
Ageratum-type
G05 Tamale, Savannah 43% Burkea africana, 20% Sapotaceae/Meliaceae, 18% — Multifloral
Ghana Anacardiaceae, 4% Combretaceae
G06 Sokodẻ, Savannah 65% Sapotaceae/Meliaceae, 65% Sapotaceae/ Unifloral
Togo 1% Ageratum-type Meliaceae
G07 Nkwanta, Savannah 50% Burkea africana, 12% Sapotaceae/Meliaceae, 11% 50% Burkea africana Unifloral
Ghana Combretaceae, 10% Anacardiaceae
G08 Nkwanta, Savannah 39% Anacardiaceae, — Multifloral
Ghana 24% Sapotaceae/Meliaceae,
6% Combretaceae, 3% Elaeis spp.
G09 Bame- Forest 48% Sapotaceae/Meliaceae, 13% Uapaca-type, 7% 48% Sapotaceae/ Unifloral
Awudome, Anacardiaceae, 6% Combretaceae, Meliaceae
Ghana 0.2% Chromolaena odorata
G10 Bawku, Savannah 56% Anacardiaceae, 56% Anacardiaceae Unifloral
Ghana 15% Sapotaceae/Meliaceae,
10% Combretaceae, 9% Poaceae
G11 Ejura, Ghana Forest 21% Helianthus-type/Bidens-type, — Multifloral
13% Poaceae, 14% Senna-type, 11% Lannea-type, 7%
Bombacaceae, 3% Combretaceae,
3% Chromolaena odorata
G12 Kete-krachi, Savannah 44% Combretaceae, — Multifloral
Ghana 14% Sapotaceae/Meliaceae,
10% Burkea africana, 3% Lannea-type
G13 Hoezo, Forest 41% Anacardiaceae, — Multifloral
Ghana 18% Chromolaena odorata, 15% Fagara-type, 11% Elaeis
spp.
G14 Kete-krachi, Savannah 60% Gynandropsis gynandra, 60% Gynandropsis Unifloral
Ghana 26% Anacardiaceae, gynandra
3% Sapotaceae/Meliaceae, 3% Combretaceae
G15 Adaklu, Forest 21% Lannea-type, 19% Elaeis spp., — Multifloral
Ghana 13% Burkea africana,
12% Sapotaceae/Meliaceae,
6% Combretaceae, 3% Chromolaena odorata, 0.2%
Eupatorium-type
G16 Techiman, Savannah– 49% Combretaceae, 18% Poaceae, 49% Combretaceae Unifloral
Ghana Forest 6% Sapotaceae/Meliaceae,
5% Chromolaena odorata
(Continued )
Plants foraged by bees for honey in Ghana 477
Table I. (Continued ).
Floral
typea
(i.e. unifloral
or
Sample Percentage pollen content Predominant multifloral
code Origin Source (pollen count, n = 500) pollen typea honey)
G17 Kpandai, Savannah 53% Combretaceae, 53% Combretaceae Unifloral
Ghana 16% Sapotaceae/Meliaceae,
7% Anacardiaceae, 7% Burkea africana
G18 Kwame Savannah– 38% Anacardiaceae, — Multifloral
Danso, Forest 17% Sapotaceae/Meliaceae,
Ghana 15% Combretaceae, 3% Afzelia spp.
G19 Tamale, Savannah 26% Combretaceae, 20% Helianthus-type, 16% Lannea- — Multifloral
Ghana type, 7% Elaeis spp.,
7% Poaceae,
4% Chromolaena odorata
G20 Nkwanta, Savannah 28% Combretaceae, 25% Burkea africana, 20% — Multifloral
Ghana Sapotaceae/Meliaceae,
17% Lannea-type
G21 Adansi, Forest 32% Mimosa pudica, 27% Elaeis spp., — Multifloral
Ghana 11% Combretaceae, 8% Lannea-type,
1% Chromolaena odorata
G22 Afram plains, Savannah– 49% Burkea africana, 31% Combretaceae, 49% Burkea africana Unifloral
Ghana Forest 5% Anacardiaceae
G23 Kete-krach, Savannah 59% Anacardiaceae, 12% Betulaceae, 8% Senna-type, 59% Anacardiaceae Unifloral
Ghana 6% Sapotaceae/Meliaceae,
0.2% Chromolaena odorata
G24 Tamale, Savannah 53% Sapotaceae/Meliaceae, 10% Combretaceae, 9% 53% Sapotaceae/ Unifloral
Ghana Burkea africana, Meliaceae
8% Lannea-type
G25 Tamale, Savannah 38% Sapotaceae/Meliaceae, — Multifloral
Ghana 31% Lannea-type,
9% Burkea africana
G26 Nkwanta, Savannah 46% Gynandropsis gynandra, 46% Gynandropsis Unifloral
Ghana 17% Anacardiaceae, 10% Elaeis spp., Gynandra
8% Combretaceae
G27 Kete-krach, Savannah 29% Burkea africana, 22% Gynandropsis gynandra, 16% — Multifloral
Ghana Combretaceae,
12% Lannea-type,
4% Sapotaceae/Meliaceae
G28 Adaklu, Forest 74% Anacardiaceae, 10% Myrtaceae, 74% Anacardiaceae Unifloral
Ghana 3% Combretaceae, 1% Chromolaena odorata
G29 Dambai, Savannah 67% Lannea-type, 20% Fagara-type, 3% Helianthus- 67% Lannea spp. Unifloral
Ghana type, 3% Combretum-type
G30 Afram plains, Savannah– 40% Combretaceae, 37% Lannea-type, — Multifloral
Ghana Forest 0.3% Chromolaena odorata
G31 Kumbungu, Savannah 26% Sapotaceae/Meliaceae, 22% Gynandropsis — Multifloral
Ghana gynandra, 18% Combretaceae
9% Anacardiaceae, 8% Burkea africana,
1% Ageratum-type,
0.1% Chromolaena odorata
G32 Kintampo, Savannah– 68% Lannea-type, 9% Poaceae, 5% Combretaceae, 4% 68% Lannea spp. Unifloral
Ghana Forest Sapotaceae/Meliaceae
3% Elaeis spp., 1% Chromolaena odorata
G33 Hoezo, Forest 43% Combretaceae, 31% Bombacaceae, — Multifloral
Ghana 14% Sapotaceae/Meliaceae
(Continued )
478 E. Letsyo and G. Ameka
Table I. (Continued ).
Floral
typea
(i.e. unifloral
or
Sample Percentage pollen content Predominant multifloral
code Origin Source (pollen count, n = 500) pollen typea honey)
G34 Sefwi- Forest 58% Burkea africana, 23% Combretaceae, 58% Burkea africana Unifloral
bekwai, 7% Sapotaceae/Meliaceae, 6% Lannea-type
Ghana
G35 Atebubu, Savannah– 49% Senna-type, 30% Helianthus-type, 5% Lannea-type, 49% Senna spp. Unifloral
Ghana Forest 4% Chromolaena odorata,
3% Grewia spp.
G36 Benin Savannah 40% Burkea africana, — Multifloral
17% Sapotaceae/Meliaceae,
17% Anacardiaceae, 8% Combretaceae
G37 Adaklu, Forest 49% Sapotaceae/Meliaceae, 10% Burkea africana, 8% 49% Sapotaceae/ Unifloral
Ghana Lannea-type, 3% Combretaceae, Meliaceae
0.3% Ageratum-type
G38 Adaklu, Forest 55% Sapotaceae/Meliaceae, 55% Sapotaceae/ Unifloral
Ghana 21% Uapaca-type, Meliaceae
6% Lannea-type
G39 Wenchi, Savannah– 37% Anacardiaceae, 17% Poaceae, — Multifloral
Ghana Forest 11% Helianthus-type, 8% Combretaceae,
4% Chromolaena odorata
G40 Ejura, Ghana Forest 57% Anacardiaceae, 14% Combretaceae, 11% Burkea 57% Anacardiaceae Unifloral
africana,
11% Sapotaceae/Meliaceae
G41 Odoben, Forest 36% Burkea africana, — Multifloral
Ghana 33% Sapotaceae/Meliaceae, 11% Combretum-type, 5%
Parkia-type
G42 Jasikan, Forest 46% Helianthus-type, 21% Lannea-type, 10% Senna- 46% Helianthus spp. Unifloral
Ghana type, 7% Poaceae,
4% Combretum-type,
3% Chromolaena odorata
G43 Atebubu, Savannah– 45% Helianthus-type, 31% Lannea-type, — Multifloral
Ghana Forest 10% Senna-type, 5% Poaceae,
1% Chromolaena odorata
G44 Atebubu, Savannah– 28% Burkea africana, 15% Anacardiaceae, 15% — Multifloral
Ghana Forest Helianthus-type, 10% Combretaceae,
3% Chromolaena odorata
G45 Afram plains, Savannah– 30% Sapotaceae/Meliaceae, 19% Burkea africana, 19% — Multifloral
Ghana Forest Lannea-type,
5% Combretaceae,
0.2% Chromolaena odorata
G46 Adansi, Forest 38% Lannea-type, 19% Ceiba spp., — Multifloral
Ghana 11% Chromolaena odorata,
7% Combretum-type, 5% Elaeis spp.
G47 Kwame Savannah– 56% Sapotaceae/Meliaceae, 56% Sapotaceae/ Unifloral
Danso, Forest 13% Anacardiaceae, 12% Burkea africana Meliaceae
Ghana
G48 Techiman, Savannah– 30% Lannea-type, 27% Gynandropsis gynandra, 16% — Multifloral
Ghana Forest Sapotaceae/Meliaceae,
14% Combretaceae
aSamples containing > 45% of a single type of pollen were considered as unifloral honey.
terised by Sapotaceae/Meliaceae (seven samples) fol- type (one sample) and Senna-type (one sample)
lowed by Anacardiaceae (four samples), Burkea afri- (Table I). The most important Secondary pollen class
cana (three samples), Combretaceae (two samples), (i.e. 16–45%) were mainly represented by Combreta-
Lannea-type (two samples), Gynandropsis gynandra ceae (11 samples), Sapotaceae/Meliaceae (11 samples),
(two samples), Meliaceae (one sample), Helianthus- Lannea-type (ten samples), Anacardiaceae (nine sam-
Plants foraged by bees for honey in Ghana 479
ples), Burkea africana (eight samples), Gynandropsis samples, in spite of the fact that they are commonly
gynandra (three samples) and Helianthus-type (three found in Ghana. The present study showed that the
samples). Furthermore, the pyrrolizidine alkaloid pro- number of pollen types per sample varies from two to
ducing forages such as Chromolaena odorata (nine sam- seven with an average value of pollen types per honey
ples) and Ageratum-type (four samples) were mostly sample of 4.5.
detected in the minor pollen class (i.e. < 3%) The honey samples sourced from the Forest
(Table I). With respect to the frequency distribution zone were found to contain varied pollen types
classes, pollen types represented as ‘Very frequent’ (i.e. (24) as compared to samples from the Savan-
> 50%) were only Combretaceae (i.e. 36 out of 48; nah–Forest transition (13) and Savannah (19)
75%) and Sapotaceae/Meliaceae (i.e. 31 out of 48; zones (Figure 4). Of these pollen types, Anacar-
65%) while Anacardiaceae (i.e. 23 out of 48; 48%), diaceae, Burkea africana, Chromolaena odorata,
Lannea-type (i.e. 21 out of 48; 44%), Burkea africana Combretaceae, Elaeis spp., Helianthus-type, Lan-
(i.e. 20 out of 48; 42%), Chromolaena odorata (i.e. 20 nea-type, Poaceae, Sapotaceae/Meliaceae and
out of 48; 42%) and Helianthus-type (i.e. 11 out of 48; Senna-type were common to the honeys collected
23%) were considered to be ‘frequent’ (i.e. 20–50%). in the three zones while some of the honey sam-
Even though the pollens of Combretaceae were found ples contained zone-specific pollens. For instance,
in 36 out of the 48 analysed honey samples (Figure 3), Afzelia spp. and Grewia spp. were detected only in
they were however not detected in the highest propor- honeys from the Savannah–Forest transition zone
tions. Conversely, Sapotaceae/Meliaceae, Anacardia- while Bombacaceae, Eupatorium-type, Mimosa
ceae and Lannea-type pollens which were recorded in pudica and Parkia-type in the Forest zone.
31, 23 and 21 out of the 48 samples, respectively were Furthermore, Combretaceae and Lannea-type pol-
however found in the highest proportions. Pollens of lens/nectar were more frequently used for honey
Afzelia spp, Ageratum-type, Betulaceae, Bombacaceae, production in the Forest zone compared with
Ceiba spp., Eupatorium-type, Fagara-type,Grewia spp., Combretaceae and Chromolaena odorata (Savan-
Meliaceae, Mimosa pudica, Myrtaceae, Parkia-type nah–Forest transition zone) and Combretaceae,
and Uapaca-type were detected in less than 8% of the Sapotaceae/Meliaceae, Anacardiaceae and Burkea
Figure 3. Frequency of occurrence (i.e. occurrence greater than 8%) of pollen types found in the 48 analysed honey samples.
480 E. Letsyo and G. Ameka
Figure 4. Frequency of occurrence (i.e. occurrence greater than 14%) of pollen types found in the honey samples from the zones.
A. Forest. B. Savannah–Forest transition. C. Savannah.
africana (Savannah zones) (Figure 4). According nant honeys were Sapotaceae/Meliaceae, Anacar-
to the pollen spectra of honey samples collected diaceae, Burkea africana and Helianthus-type
in the three apicultural zones, unifloral/predomi- (Forest zone); Combretaceae, Burkea africana,
Plants foraged by bees for honey in Ghana 481
Lannea-type, Senna-type and Sapotaceae/Melia- the three zones reflected the rich and diverse flora of
ceae (Savannah–Forest transition zone); and the West African sub-region. In comparison with
Combretaceae, Burkea africana, Lannea-type, honey from other West African countries, a common
Sapotaceae/Meliaceae, Gynandropsis gynandra and feature was the frequent use of the pollen of Combre-
Anacardiaceae (Savannah zones) (Table I). taceae for honey production by the bees (Ige & Oba-
sanmi 2014; Azonwade et al. 2017). Interestingly,
there were more common pollen types detected in
Discussion honeys from the Forest and Savannah zones in spite
In Ghana, beekeeping has become an important of the fact that the Savannah zones are usually char-
activity which contributes greatly to the economic acterised by reduced availability of floral sources (due
activities in the food industry. However, most bee- to their uni-modal rainfall pattern) compared to the
keepers have little or no information on honeybee bi-modal rainfall pattern in the Forest zone. Another
forage sources in their localities. It is therefore interesting result was the fact that relatively high num-
necessary to document important plant species in bers of pollen types were found in honeys from the
Ghana through melissopalynological analyses of Savannah zones as compared with that of the Savan-
honeys. Establishment of inventories of the most nah–Forest transition zone despite its rich and diverse
important bee plants in the three main agro- flora. This may be due to the fact that the bees have
ecological honey producing zones could potentially more floral choices in the Savannah zones for honey
lead to increase honey production. production relative to that of the Savannah–Forest
The 27 different pollen types detected in the 48 transition zone. The results also showed that bee
analysed honey samples demonstrates that honeybees forages are mostly characterised by trees, shrubs and
have fewer forage preferences for honey production in herbs which are both nectariferous and polleniferous.
Ghana compared with other West African countries The presence of the pollen grains in all the honey
(Ige & Obasanmi 2014; Azonwade et al. 2017), albeit samples were indicative of plants which are typically
each sample exhibited diversity in their composition abundant in Ghana and also an indication that the
(Table I). All the honey samples were characterised by honeys were not of any other adulterated source.
the presence of pollen grains typical of the country’s
vegetation. Nevertheless, since the preferred bee forage
Conclusions
sources for honeymaking are usually related to the high
pollen frequencies; Combretaceae, Sapotaceae/Melia- Melissopalynological analysis of Ghanaian honeys has
ceae, Anacardiaceae, Lannea-type and Burkea africana been carried out. This analysis has provided insights
can therefore be described as themajor sources for both into our knowledge of themost important nectariferous
nectar and pollen in the studied localities. This finding and/or polleniferous bee forages which could assist bee-
is in a good agreement with previous reports in the sub- keepers in the identification of suitable sites as well as
region (Abbiw 1990; Ige &Obasanmi 2014; Azonwade preserving these forages around apiaries in order to
et al. 2017; Letsyo et al. 2017). Although Combreta- maximise honey production. On the basis of the results
ceae pollens were most frequently used by bees for obtained from the present study, 27 pollen types
honey production, Sapotaceae/Meliaceae pollens were belonging to eight families, 15 genera and four species
however found in the highest proportions (i.e. > 45%) were detected. Pollen spectra revealed that 48% of the
in seven honey samples compared with two samples honey samples were uniflora comprising mainly of
containing Combretaceae pollen. Sapotaceae/Meliaceae, Anacardiaceae and Burkea afri-
Determining the distributions of bee floral sources cana nectar sources. Also, the pollens of Combretaceae,
in the three main apicultural zones of the country is Sapotaceae/Meliaceae, Lannea-type, Anacardiaceae
imperative as this could guide beekeepers in the loca- andBurkea africanawere frequently seen in the analysed
tion of their apiaries in these zones. The relatively high honey samples.With respect to the distribution of these
number of pollen types detected in the Forest zone plant species in the apicultural zones, honey samples
honeys reflects the abundance/richness of pollen in the sourced from the Forest zone were found to contain 24
honeys sampled from this zone relative to that of pollen types with Combretaceae and Lannea-type pol-
Savannah and Savannah–Forest transition zones. The lens/nectar being the most frequently used for honey
different pollen types determined vary according to the production as compared to samples from
agro-ecological zones even though some plant species the Savannah–Forest transition (13; Combretaceae
were common in all three zones. The common plant and Chromolaena odorata) and Savannah (19;
species indicate the key role their nectars play in honey Combretaceae, Sapotaceae/Meliaceae, Anacardiaceae
production in these vegetation belts of the country. and Burkea africana) zones. The unifloral/predominant
The pollen spectra of the honey samples analysed in honeys in the Forest zone comprise of Sapotaceae/
482 E. Letsyo and G. Ameka
Meliaceae, Anacardiaceae, Burkea africana and Brodschneider R, Crailsheim K. 2010. Nutrition and health in
Helianthus-type while that of the Savannah–Forest tran- honey bees. Apidologie 41: 278–294. doi:10.1051/apido/
sition zone honeys (Combretaceae, Burkea africana, 2010012.
Ige OE, Obasanmi OO. 2014. A palynological assessment of
Lannea-type, Senna-type and Sapotaceae/Meliaceae) honey samples from delta state, Nigeria. American Interna-
and Savannah zones (Combretaceae, Burkea africana, tional Journal of Biology 2: 47–59.
Lannea-type, Sapotaceae/Meliaceae, Gynandropsis Jones GD, Bryant VM. 1996. Melissopalynology. In: Jansonius J,
gynandra and Anacardiaceae). This study therefore McGregor DC, eds. Palynology, principles and applications,
expands the knowledge of the relation between the 933–938. Salt Lake City, UT: AASP Foundation.
bees and their forage sources and by extension, apicul- Kerkvliet JD, Shrestha M, Tuladhar K, Manandhar H. 1995.Microscopic detection of adulteration of honey with cane
tural businesses in Ghana. sugar and cane sugar products. Apidologie 26: 131–139.
doi:10.1051/apido:19950206.
Letsyo E, Jerz G, Winterhalter P, Dübecke A, von der Ohe W,
Acknowledgements von der Ohe K, Beuerle T. 2017. Pyrrolizidine alkaloids in
This work on Ghanaian honeys could not have been floral honeys of tropical Ghana: A health risk assessment.Food Additives & Contaminants Part B 10: 300–310.
carried out without the assistance of Werner von der Louveaux J, Maurizio A, Vorwohl G. 1978. Methods of
Ohe and Kathrine von der Ohe of the Institut für melissopalynology. Bee World 59: 139–157. doi:10.1080/
Bienenkunde, Celle, Germany. The first author is 0005772X.1978.11097714.
grateful to them for providing their research labora- Luz C, Barth O. 2012. Pollen analysis of honey and beebread
tories for the analyses. derived from Brazilian mangroves. Brazilian J Botany 35:
79–85. doi:10.1590/S1806-99592012000100009.
Sahney M, Kumar A, Rahi S. 2016. Pollen analysis of honeys
Disclosure statement from Varanasi District, Uttar Pradesh, India. Biological
Forum – An International Journal 8: 126–133.
No potential conflict of interest was reported by the Salonen A, Ollikka T, Grönlund E, Ruottinen L, Julkunen-
authors. Tiitto R. 2009. Pollen analyses of honey from Finland.
Grana 48: 281–289. doi:10.1080/00173130903363550.
Schulz E, Lueke M. 1994. A two-year pollen calendar for tradi-
References tionally produced honey types from Gaya, southern Niger.
Grana 33: 254–259. doi:10.1080/00173139409429007.
Abbiw DK. 1990. Useful plants of Ghana: West African use of Selva-Singh RP, Muthukumar S, Malleshappa H. 2011. Rela-
wild and cultivated plants. Kew: Intermediate Technology tionship between floral characters and floral visitors of
Publications and the Royal Botanic Gardens. selected angiospermic taxa from Kalakad Mundanthurai
Admasu A, Debissa L. 1996. Preparation of flowering calendar: Tiger Reserve, Southern Western Ghats, India. Indian Fores-
Survey of the honey plants and preparation of flowering calendar ter 137: 962–975.
in Rift valley regions of East Shewa zone. Holeta: Holeta Bee Silici S, Gökceoglu M. 2007. Pollen analysis of honeys from
Research Center. mediterranean region of Anatolia. Grana 46: 57–64.
Al-Jabri AA. 2005. Honey, milk and antibiotics. African Journal doi:10.1080/00173130601138783.
of Biotechnology 4: 1580–1587. von der Ohe W, Persano OL, Piana ML, Morlot M, Martin P.
Azonwade FE, Paraïso A, Tossou MG, Sina H, Kelomey AE, 2004. Harmonised methods of melissopalynology. Apido-
Chabi-Sika K, Baba-Moussa L. 2017. Pollen analysis of the logie 35: 18–25. doi:10.1051/apido:2004050.
honeys samples produced in the three phyto-geographical Winston ML. 1991. The biology of the honey bee. Cambridge,
zones of Benin. European Scientific Journal 13: 1857–7431. MA: Harvard University Press.