Gum Yield Presentation_2012

8/13/2019 Gum Yield Presentation_2012

http://slidepdf.com/reader/full/gum-yield-presentation2012 1/20

C. Wekesa, J. Lelon, M. Muga, A. Luvanda & B. Chikamai

GUM ARABIC PRODUCTION POTENTIAL

OF NATURAL Acacia senegal VARIETIES INDRYLANDS-KENYA

KENYA FORESTRY RESEARCH INSTITUTE



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




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




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)




Acacia senegal VARIETIES IN KENYA

L S K




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




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




MAP FOR STUDY SITES



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




TAPPING?




DOES TAPPING IMPROVE QUALITY?

Natural ExudatesClean tapped gum




RESULTS




RESULTS CONTINUED……




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)




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




OVERALL MEAN GUM YIELD




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




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




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




END

THANK YOU

COMMENTS/QUESTIONS?


Gum Yield Presentation_2012

Documents

Transcript of Gum Yield Presentation_2012