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C. Wekesa, J. Lelon, M. Muga, A. Luvanda & B. Chikamai
GUM ARABIC PRODUCTION POTENTIAL
OF NATURAL Acacia senegal VARIETIES INDRYLANDS-KENYA
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INTRODUCTION
• Drylands 84% of Kenya, support 34 % of human population
• Low annual rainfall 150-450 mm; High annual temp-28oC
• Poor soils
• Productivity quite low• Nomadic pastoralists & agro-pastoralists are inhabitants-
depend on livestock & small-scale irrigated agriculture
• Prolonged drought & insecurity fueled by ethnic conflict
thro’ livestock raiding & banditry-Loss of livestock• Rapid population growth cause environmental
degradation
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INTRODUCTION CONT’D…..
•
Poverty levels high- despite rich diversity of NRs like AS produces commercial GA
• AS is currently under utilized in Kenya
• Tree holds the potential to fetch alternative sources of
income for the nomadic communities – reducing poverty• Earn the country foreign exchange thro’ export of GA
• Need to obtain data that will promote increased GA
production
• Promote sustainable management of AS & conserve the
environment
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GA & PRODUCING VARIETIES
• What is GA? Natural exudate ( A. senegal or seyal)
• AS grows to 2-15 m tall, flat or rounded crown
• Highly branched with many upright twigs
•Widely distributed as it tolerates aridity and eroded soils
• Extensively spread in tropical & sub tropical Africa-S.
Africa northwards to Sudan
• Kenya: Baringo, Turkana, Kajiado, Samburu, Isiolo,
Mwingi & Taita Taveta counties
• 3 varieties ( kerensis, senegal & leiorhachis)
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Acacia senegal VARIETIES IN KENYA
L S K
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STUDY OBJECTIVES
Broad objective:To determine gum arabic production potential of naturally
growing A. senegal varieties in Kenyan drylands
Specific objectives:
1. To determine and analyze the gum arabic yieldvariations in relation to different varieties of A. senegal
2. To investigate the impact of site conditions and tree sizeand/or age of the on gum yield
3. To investigate the effect of tapping as a tree managementstrategy in optimizing gum arabic production
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SITES’ LOCATIONS AND ELEVATION
Site County Northings Eastings Altitude (m.a.s.l)
Ntumburi Isiolo 00o11'29. 9" 037
o30'46. 7" 1725
Ngare Ndare Isiolo 00o30'39. 1" 037o22'16. 1" 984
Daaba Isiolo 00o32'00. 2" 037o45'39. 9" 935
Kulamawe Isiolo 00o33'32. 8" 038
o01'38. 6" 750
Kajiado Kajiado 01o53'08. 6" 036
o45'25. 4" 1741
Rimoi Baringo 00o39'52. 5" 035
o34'16. 4" 1152
Solit Baringo 00o25'38. 4" 035
o55'06. 5" 1283
Kimalel Baringo 00o27'00. 0" 035
o52'00. 0" 1686
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MAP FOR STUDY SITES
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SAMPLING METHODOLOGY
• Multi stage sampling• 1 Ha plot
• Diameter classes (3.0-6.0, 6.1-9.0 and >9.0 cm), 10 trees
• Tapped either on stems or branches-depending on the diameter ofstem and the branches
• Branches with a diameter = or > arm’s wrist (>3.0 cm) tapped
• Trees - a diameter < 3.0 cm tapped on main stem (1 wound)
• Tapping 3 weeks after end of long rain season, shed about 50% ofthe leaves
•Incision (80 by 2.5 cm)
• 1st picking, 4 weeks from tapping date, regular interval of 2 weeksuntil end of dry season
• Only productive trees considered in analysis & reporting
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TAPPING?
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DOES TAPPING IMPROVE QUALITY?
Natural ExudatesClean tapped gum
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RESULTS
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RESULTS CONTINUED……
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COMPARISON OF MEANS
Site
Tapped Non-TappedDiameter class (cm) Diameter class (cm)
3.0-6.0 6.1-9.0 >9.0 cm 3.0-6.0 6.1-9.0 >9.0
DB 12.48a 12.90a 42.59a 11.33a 11.6a 20.33a
NN 10.42a 17.28a 12.60b NP 5.14b 10.31b
NT 28.53b 21.06b 14.39b 18.38b 7.33b 6.67c
KM5.24c 3.98c 3.72c 3.24c NP NP
RM 14.19a 26.86b 24.09d 5.62c 9.83a 5.11c
KL 27.48b 19.84b 11.55b 9.25a 8.77a NP
SL 25.37b 10.91a 11.62b NP NP 7.47c
KJ NP 8.08a 7.17c NP NP 6.45c
DB-Daaba, NN-Ngare Ndare, NT-Ntumburi, KM-Kulamawe, RM-Rimoi, KL-Kimalel,
SL-Solit and KJ-Kajiado
Results marked with different alphabetical letters in the columns are significantly
different (p<0.05)
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MIN., MAX. & RANGE VALUES OF GA YIELD
Tapped Non-Tapped
Site Class (cm) Min. Max. Range Min. Max. Range
DB 3.0-6.0 4.8 43.6 38.8 8.5 16.7 8.2
6.1-9.0 3.7 32.8 29.1 4.3 29.9 25.6
>9.0 10.7 64.7 54.0 3.2 33.0 29.8
NN 3.0-6.0 5.0 32.3 27.3 NP NP NP
6.1-9.0 6.1 18.7 12.6 5.1 5.1 0
>9.0 6.1 18.9 12.8 4.7 29.9 25.2
NT 3.0-6.0 11.9 53.2 41.3 4.0 69.5 65.5
6.1-9.0 4.1 58.0 53.9 3.4 12.8 9.4
>9.0 3.7 24.7 21.0 3.3 11.0 7.7
KM 3.0-6.0 5.2 5.2 0 3.2 3.2 0
6.1-9.0 4.0 4.0 0 NP NP NP
>9.0 3.7 3.7 0 NP NP NP
RM 3.0-6.0 3.5 40.2 36.7 3.4 8.6 5.2
6.1-9.0 4.7 91.2 86.5 3.4 30.0 26.6
>9.0 5.3 86.4 81.1 2.8 6.5 3.7
KL 3.0-6.0 7.2 51.4 44.2 3.9 17.6 13.7
6.1-9.0 3.8 45.4 41.6 7.9 9.6 1.7
>9.0 4.2 17.8 13.6 NP NP NP
SL 3.0-6.0 4.1 83.8 79.7 NP NP NP
6.1-9.0 3.4 25.4 22.0 NP NP NP
>9.0 3.3 36.8 33.5 7.5 7.5 0
KJ 3.0-6.0 NP NP NP NP NP NP
6.1-9.0 3.9 14.6 10.7 NP NP NP
>9.0 3.4 17.1 13.7 3.4 15.4 12.0
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OVERALL MEAN GUM YIELD
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PROJECTED YIELD/UNIT AREA
Site Overall mean Estimated stems/Ha Kg/Ha
Daaba 16.4 333 5.5
Kulamawe 4.7 333 1.6
Ngare Ndare 11.3 333 3.8
Ntumburi 18.2 333 6.1
Rimoi 15.9 333 5.3
Kimalel 17.7 333 5.9
Solit 14.6 333 4.9
Kajiado 7.1 333 2.4
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LIMITATIONS
• Severe & prolonged drought had a huge impact on theresults regarding GA yield, was very low than what was
expected
• Experiments conducted in wild, sample plots accessibleto locals making it difficult to have controlled
monitoring-Plots located near Manyattas
• Competition for gum from wild animals especially
baboons, interfered with the results
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CONCLUSIONS AND RECOMMENDATIONS
• Size & age of A. senegal trees influenced gum yield/individual
tree/season for A. senegal var. senegal and A. senegal var.
leiorhachis
• Tapping increased yield by 47.1%, 91.8% & 85.7% for trees
occurring in diameter classes 3.0-6.0, 6.1-9.0 & >9.0 cm
• Untapped trees didn’t produce at all/produced little gumimplying that tapping is an important management tool for
enhancing gum productivity
• Varieties kerensis & senegal have potential for
commercialization• Selection of high producer trees from both natural stands for
multiplication – to enhance production. Caution, multiplication
should ensure site matching is taken into account
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END
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