Livestock Research for Rural Development 25 (1) 2013 Guide for preparation of papers LRRD Newsletter

Citation of this paper

Identification and evaluation of propagation techniques of a native bee forage, ‘tebeb’ (Becium grandflorum)

Haftom Gebremedhn and Kebebew Wakijira*

Department of Apiculture and sericulture, Mekelle Agricultural Research Center, Tigray Agricultural Research Institute,
P.O.Box 492, Mekelle, Tigray, Ethiopia
* Holeta Bee Research Centre, P.O. Box 22, Holeta, Oromia, Ethiopia


The study was conducted in Mekelle Agricultural Research Center, Mekelle. It was designed to identify and evaluate different propagation techniques of Becium grandiflorum, one of the best honey source plants of Ethiopia. Six propagation techniques were considered, namely plant cutting, seed sowing, seedling transplanting, splitting/dividing main branch of the mother the plant, air layering and ground layering. Each propagation technique was considered as a treatment. s

The study found that there were difference among the treatments in canopy cover, height, number of flowers,  branches and seeds per plant. From these investigations, it is concluded that propagation of B. grandiflorum by cuttings is the best for attaining maximum flower numbers with a mean of 12910, while sowing is the least with a mean flower numbers of 5637. The study also found that the species is easy to propagate by cuttings and transplanted seedlings. 

Key words: flower number, honeybee, treatments


Becium grandiflorum (Lam.) Pic.Serm. is a drought tolerant species endemic to the highlands of Ethiopia and Eritrea (Bein et al 1996; Fichtl and Admassu 1994; Guinad and Dechassa 2001). B. grandiflorum is a medium sized, aromatic woody shrub that belongs to the family of Lamiaceae. It is locally known as Tebeb (Tigrigna) or Mentesie (Amharic). The species   grows on eroded soils, particularly in rocky slopes and sandy soil, in mountain bush land and pastures. The species spans over altitude ranges of 1600 m and 3100 masl. (Fichtl and Admassu 1994).   

B. grandiflorum is valued for various purposes. The numerous showy pale pink flowers, together with their violet veins and fragrance, are very attractive to honeybees. Thus, honeybees visit  flowers of the plant for collecting the pollen and/o nectar. The colour of the honey is creamy white and granulates rapidly. Because of its attractive colour and also light to taste, the honey is preferred by many consumers. As a result, honey from this species fetches premium price both in the local and international markets (Taddele and Nejdan 2008). And hence the plant ranked as the best honeybee forage by beekeepers (Fichtl and Admassu 1994; Guinad and Dechassa 2001; Haftom et al 2011; Alemtsehay 2011)

The species has also a very good value as fuel wood and human food (the whole flower is plucked from a branch and eaten fresh), for cleaning threshing ground, covering roofing of houses, food flavoring, traditional medicine against malaria, soil and water conservation (Guinad and Dechassa 2001; Nurya 2010). B. grandiflorum is also well-known to have positive effects on crop production and is common in Tigray region's traditional agroforestry systems. Some of the identified agro-forestry qualities include: high quantity and quality litter production, faster litter decomposition rates, and possession of spreading canopy (Descheemaeker et al 2006).    

Nevertheless, B. grandiflorum is currently threatened with declining population in the area due to population pressure and the concomitant farmland expansion, as well as use for variety cultural household tools. On top of this, increased demand for fuel wood has led to intensified extraction of mature plants from their natural habitats. As a result, many landscapes, which once contained rich stands of B. grandiflorum are presently found to contain only relics of this remarkable species. In addition, natural regeneration of the species from seeds has become very difficult due to widespread human interference and also due to climate change, thus further jeopardizing the very survival of the species.

The major objective of this study was to identify and evaluate different propagation methods and select the best method for the fast production of the plant biomass.

Materials and methods

Description of study areas 

The study was carried-out at Mekelle agricultural research center, Illala site. Illala is located North-east of Mekelle at an elevation of 1970 m.a.s.l, at 250 51’N latitude and 390 61’ longitudes. The predominant soil type in the study area is black clay (Vertisol). 

Seeds and mother plants collection

For this study, mature seeds and branch cuttings / mother plants / of  B.grandiflorum were collected from comparatively elite plants from the beginning of  June to the end of December  (2008). The seeds and branch cuttings were collected from Atsbi-wonberta district. Geographically, it is situated between 39º 30' – 39º 45' E and 13º 30' – 13º 45' N. The site was selected on the basis of: availability, potential and access to transport.

Seeds were collected from 30 plants by selecting mature fruits on September to November, 2008. Immediately after collection, seeds were packed in perforated polyethylene bags and allowed to dry for one month at room temperature. The packages were maintained at room temperature until day of sowing (April 2009). Then seeds were taken out of these packages, for propagating the plant in plastic pots and direct sowing in the soil.

In addition to this a total of 80 young mother plants which had the same provenance were collected from this district, to be used as source of planting materials. They were planted in Mekelle Agricultural Research Center, Illala site. The planting materials were collected at the beginning of rainy season /June, 2008/ and transplanted within the same day. There was also direct watering of the mother plants after transplanting. This was done to avoid moisture stress and to establish easily.

After collecting the planting materials, preliminary observation trial was done to identify propagation method/s of the plant. Throughout the observation trial six successful propagation techniques of B.grandiflorum were identified; sowing, cutting using pot, plant splitting, air layering, ground layering and transplanting seedlings. Then, the study was continued to evaluate the identified propagation technique/s of the plant in the experimental plot.   

Experimental management 

To evaluate the propagation techniques of the plant  60 number of plastic sleeves (diameter, 8cm; length, 15cm) were prepared by filling them with a soil mixture of silt , sand  and manure at the ratio of 20: 2: 5, respectively for each treatments of seedling and cutting . Seeds and cuttings were planted in the plastic sleeves (April, 2009).

The seeds were covered with a thin layer of the same soil mixture and watered by sprinkling irrigation to avoid erosion. The sleeves were then arranged on the ground in open air. Dried grass stalks were used to cover the mouth of the arranged sleeves for conserving moisture. The grass cover was removed as the seeds germinated and germinant emerged to the surface of the soil. While germination of the seeds /70 %/ started at 30 th days, transplantation of the seedlings to the experimental plot was done at 52th days (on July, 2009) to have matured roots.

To compare germination responses in plastic sleeves with those in the open field, seeds were planted in rows on a plot of land prepared with soil mixture indicated above. To keep proper spacing and avoid nutrient competition, thinning of seedlings was done at 56th days from the time of sowing (at 75% date of germination). Finally the newly emerged seedlings transplanted to the experimental plot after 70 days from the time of sowing.  

For evaluating cutting way of propagation 60 cuttings with a height of 40cm were collected early in the morning from 10 natural matured young and healthy mother plants. The cuttings had adequate number of green leafs (5 to 12) to initiate photosynthesis. The green leafs were partially injured to stimulate new growth. To avoid the direct entrance of water during planting and growing period, the cuttings were prepared in such a way as the top ends have a slant surface (angle of 45°) vertically, and contain a minimum of two nodes. Finally transplantation of the seedlings to the experimental plot was done at 55 days at survival rate of 68%. 

To raise new plants from layering each stem was attached to the parent plant. For raising new plants from air layering and ground layering 50 matured and young branches each were selected from the established mother plants.  

For air layering to form roots on the aerial part of a plant, the stem was girdled or slit with sharp knife just below a node /at least 30 to 50 cm from the tip/. Wounding of the stem was done on one side of the stem just below a node. The wound of the stem was enclosed via a moist rooting medium soil /with the above soil mixture/ at the point of injury. Then plastic wrap and proper sealing was done to keep the layer from drying out and to retain the moisture around the wounded area for weeks/months. Finally simple cutting of the branch was done closely to the new plant. This was done after the selected branches developed mature roots /after 34 days after root initiating the branches/. Before removing the plastic cut off the new plant was done just below the roots. The seedlings were transplanted at 48th day directly after cutting the newly emerged seedlings from their mother plants. During transplanting the new plants to the experimental plot there was plenty of soil around the roots.

Ground layering was done by bending selected branches. The middle portion of the selected branches were put in the ground (i.e., shoot tip comes back up above ground) under the existing soil. The branches had enough length / 50 to 70 cm/ from the tip so a few inches of leaves were left on the tip. The stem bend to the ground was covered part of it with the above soil mixture and the rest were leaved, exposed. For ground layering even the branches started root initiating at 16th day, cutting of the newly emerged seedling from their mother plant was done at 26th days to have well developed roots.  Cutting of the stem was done just below the rooted zone. Lastly, the seedlings were transplanted to the experimental plot directly  after cutting the branches from their mother plants / after 41 days from the time of covering the branches with the above soil mixture/. 

For splitting mother plants which had more young branches were selected from the established mother plants. Then there was watering of the mother plants once a weeks for continuous 55 days to have green leaf and to split the braches easily from their mother plants without injuring their roots. Finally transplanting and splitting of the seedlings was done after 50 days from beginning of watering the mother plants.  

For all treatments to avoid moisture stress, the newly emerged seedlings were transplanted early on the morning and planted on the same day. All the young plants or seedlings deriving from the different propagation techniques were planted in pits of 20cm in diameter and depth. After transplanting the seedlings to the experimental plot, the plants were supplemented with irrigation once a week when there was no rain falls from November to June. 

Statistical analysis
Data collection and analysis

To collect the data five plants were taken randomly per plot and a total of fifteen plants per treatment. The data were collected on the following parameters.

Canopy cover was calculated by  

C.C = (D1 +D2)/2 


Where D1 is diameter of the plant toward the larger coverage direction, D2 is diameter of the plant towards the small coverage direction and C.C – is canopy cover of the plant in cm. And then the canopy cover of the plant was expressed in terms of the average diameter in cm.  


The total number of flowers per plant was calculated by counting the total flower head per plant and number of flowers per flower head. The total number of flowers per plant was calculated by:  

T.F = H.F *N.F.H 

Where T.F – total number of flowers per plant, H.F- Number of Flower Head per plant and N.F.H is Number of flowers per head flowers. To know the number of flowers per flower head a sample of 10 flower head per plant was taken randomly.   

The height of the plant was measured from ground level to the tip of the largest branch with the help of a measuring rod. Actual number of branches and seed per plant were determined by direct counting and recording. 

The collected data was statistically analyzed using the one-way ANOVA analysis of variance, and LSD to identify differences among the means of treatments using Genstat 13th version statistical software. Correlation analysis was applied for specific variables using SPSS version 16.  

Result and discussion

Propagation types  

In this study six successful propagation techniques (Photo1-6) of B.grandflorum were identified; cuttings, seed sowing, transplanting seedlings, plant splitting, air layering and ground layering. However Bein et al (1996) stated that B.grandflorum could be propagated through seedlings. Among the techniques, the vegetative propagation needs mother plants for multiplying the plant. However, the new seedlings produced through air layering can be transplanted to introduce to new areas.  

Unlike splitting and taking cuttings, ground layering and air layering had an advantage in that they multiplied the plant without damaging the mother plants. All these vegetative propagation techniques, unlike splitting can be used as way of pruning the branches of the mother plants and propagating the plants at the same time. The number of young seedlings raised through air layering, cutting and ground layering was depending on the number of young branches of the mother plants.  

Photo 1.  B.grandiflorum through Ground layering Photo 2.  B.grandiflorum  through air layering

Photo 3.  B.grandiflorum through plant splitting Photo 4.  B.grandiflorum through transplanting seedling

Photo 5.  B.grandiflorum through seed sowing Photo 6. B.grandiflorum through Cuttings using plastic pot
Height, number of branches and canopy cover

Concerning the height of the plant there were no sdifference among the treatments (Table 1).  Bein et al (1996) illustrated that the height of the plant naturally ranges from 0.4m to1.0m and Guinad and Dechassa (2001) stated it can reach up to 1.5m of height. 

Ground layering had the highest number of branches per plant (12), while seedlings had the smallest number of branches (7) per plant. Height of the plant had weak negative correlation with number of branches per plant (r= -0.16).

Regarding to canopy cover differences were found between the treatments (Table 3). Plants propagated through cuttings showed the greatest canopy cover (116 cm); while seedling had the smallest canopy cover (88 cm). Canopy cover had positive correlation with the number of branch per plant (r = +0.30), while it was correlated negatively with plant height (r= -0.05).

Differences were found between the treatments in number of flowers per plant (Table 2). The plants propagated from cuttings had the highest number of flowers (12,910); whereas the plants propagated through sowing had the smallest number of flowers (5637) per plant. The variation on the number of flowers per plant among the techniques might be due to the differences on the number of branches per plant. John et al (1987) also revealed that the more vegetative growth of a plant develops to more flowers and seeds. As demonstrated in Table 2 the number of flowers per plant had positive correlation with the number of branches (r = +0.29) and negative correlation with height (r = -0.02) per plant. Rajesh (2010) also reported a significant positive correlation of flower number per plant with primary branch number and secondary branch number in Linum usitatissimum L.  

Table 1: Canopy cover, branch, height, flowering period, flower number and seed of  B. grandiflorum/ Tebeb across different propagation techniques 























































*** , ** and *  = significant at P<0.001, 0.01, and 0.05 respectively C.C – canopy cover in cm , N.B- Number of branches, H, Height in cm , F.N- Total flower number per plant ,S.P- Total seed per plant, AL- Air layering, CP- cutting using pot, GL- Ground layering, SE, Seedling, and SP-splitting

Concerning the flowering period, the plant had a long flowering period and it was giving flowers up to 76 days. On average the flowering period of the plant was 65.5 days. The plant had an indeterminate flowering pattern. These characters of the plant allow honeybees to collect more pollen and nectar over a long period of time per flowering season. As illustrated by Reinhard and Admasu (1994) and proven in this study, honeybees highly visited the flowers of the plant for collecting both the pollen and nectar ( photo 7 and 8) and the flowering frequency of the plant depend on the availability of water. The plant flowered up to four times a year by supplementing  irrigation once a week in the dry season  /from November to June /. This indicated that when the plant gets enough water its flowering frequency will be increased.  

Table 2: Correlation coefficient (r) between variables among canopy cover, branch number, flower number, seed, and height





































***, ** and * = significant at P <0.001, <0.01 and <0.05 respectively

The study noted a significant difference in seed production potential between the means of the treatments. Cuttings had the highest number of seeds per plant, while air layering had the smallest number of seeds per plant. This might be due to difference on the number of flowers and branches among the techniques. And as described by John et al (1987) plants that grow longer vegtatively before flowering are typically bigger and able to support more reproductive growth. Thus, the seed yield per plant had significant positive correlation with the number of flowers (r =+ 0.5) and number of branches (r=+ 0.57) per plant. However, the seed potential of the plant had negative correlation (r=-0.14) with plant height.

Photo 7.  Matured B.grandiflorum at time of flowering

Photo 8. When honeybees collecting pollen and
nectar from B.grandiflorum
Photo 9. When honeybees collecting pollen
from B.grandiflorum



We acknowledge Tigray Agricultural Research Institute, Mekelle Agricultural Research Center for the financial support during data collection. Finally, we wish to express our deepest appreciation and thanks to Ms. Pam Gregory, Mr. Tewlde Gebretnsae  and researchers of Mekelle Agricultural Research Center for their valuable comments and special support.  


Alemtsehay T 2011 Seasonal availability of common bee flora in relation to land use and colony performance in Gergera watershed Atsbi Wembwrta district eastern zone of Tigray, Ethiopia. A thesis submitted to the department of forestry and natural resources, Wondo genet college of forestry and natural resources, school of graduate studies, Hawassa university wondo genet, Ethiopia. 

Bein E, Habte H, Jaber A, Birnie A and Tengnas B 1996 Useful trees and shrubs in Eritrea. Technical hand book No 12. 

Descheemaeker K, Muys B, Nyssen J, Poesen J,   Raes D , Mitiku H and  Deckers J 2006 Litter production and organic matter accumulation in exclosures of the Tigray highlands, Ethiopia. Forest Ecology and Management 233 (2006) 21–35. 

Fichtl R and Admasu A 1994  Honeybee flora of Ethiopia.  The national herbarium, Addis  Ababa university, Deutscher Entwicklungsdienst (DED).  Margraf verlag, Germany.   

Guinad Y and Dechassa L 2001 Wild-food Plants in Ethiopia. Reflections on the role of  'wild-foods' and  ‘famine-foods’ at a time of drought. United Nations Development Programme, Addis Abeba, Ethiopia. 

Haftom G, Zelealem T, Girmay M  and Awet E  2011 Honeybee flora seasonal availability and honeybee seasonal activity and managemental interaction in Debrekidan and Begasheka watershed, Tigray, Ethiopia. Proceedings of the workshop on accomplishments of the operational research project (2008- 2011). April 29-30, 2011, Mekelle, Ethiopia, pp. 72-84" 

John B A,Gordon R H and Parrish D J 1987 Plant Science. McGraw-Hill publishing Company.126582. 

Nurya A 2010 Ethnobotanical study of medicinal plants used by local  people in Ofla wereda, southern zone of Tigray region,  Ethiopia ,Addis Ababa University. From 

Taddele A and Nejdan Y 2008  Beekeeping and honey production in  Tigray region, Ethiopia. From 

Rajesh K  J 2010 Correlation study of flowering performance and pattern with the yield in Linumusitatissimum L. African Journal of Plant Science Vol. 5 (3), pp. 146-151.

Received 25 July 2012; Accepted 2 August 2012; Published 4 January 2013

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