Presentation outline
• Banana systems characteristics in Africa
• Key banana pests and disease in Africa
• Risks associated with key pests and diseases
• Mitigation strategies
Region Year
2009 2010
Africa 40,158,682 tonnes 39,653,941 tonnes
Eastern Africa 22,073,329 tonnes 21,533,708 tonnes
Middle Africa 6,288,916 tonnes 6,361,672 tonnes
Northern Africa 1,984,793 tonnes 1,993,270 tonnes
Southern Africa 376,505 tonnes 399,021 tonnes
Western Africa 9,435,139 tonnes 9,366,270 tonnes
Banana Production in Africa: Systems characteristics
FAO production data, 2012
AAA-EAHB
PLANTAINS
Cavendish
Cavendish
31%
49%
17%
3%
Plantains AAB
East African highland bananas + ABB,AAB,AA
Cavendish AAA
Gros Michel & other AA,AAA,AAB,ABB
Main banana production systems in Africa
Lescot, 2010
Systems characteristics cont’d
Systems Characteristics cont’dBanana in diets in Africa
D R C on go
U ganda
K en ya
Tanzania
R w an da
B urun di
Ba n a n a d ie t s h are (% )N o d ata0 - 55 - 1 010 - 2020 - 3030 - 5050 - 10 0
7
0
50
100
150
200
250
kg /
capi
ta /
yr
Sour
ce: F
AO
STA
T
Systems Characteristics cont’d:
Consumption in eastern and southern Africa
Cameroon South Nigeria
Children 182 8
Mothers 362 212
Ref: Honfo FG, et al, 1996
Systems Characteristics cont’d:
Annual per capita plantain consumption in Nigeria and Cameroon (Kg)
0 100 200 300 400 500 600
Sugar
Poultry
Beans_Peas
Wheat_Barley
Rice
Potatoes_Sweetpotatoes
Coffee_Tea
Bananas
Maize
Beef
Vegetable_Fruits
Sorghum_Millet
Cassava
Oilseeds
Milk
Regional Regional GDP Gains to 2015 from Growth in Selected GDP Gains to 2015 from Growth in Selected Commodity SubCommodity Sub--Sectors (US$ million)Sectors (US$ million)
Systems’ characteristics cont’d
• Especially in eastern and west Africa, the banana systems are • slow-changing and rural-based economies
• under stress due to population pressure/decreasing farm size; decreasing land fallow periods and production progressively unable to meet household needs.
• facing additional stresses, including climate change, characterized by increasing temperatures and greater rainfall variability; and
• changing social structures due to HIV-AIDS, rural-to-urban migration and declining returns from agriculture.
Systems’ characteristics
• Smallholder banana production as a system in Africa is built to a large extent on an informal seed system with minimum attention to quality.– Informal seed systems account for 95-98% of the seed
exchanges– lacks a well organized seed system to subtend sustained
production– Planting material is the principle mechanism for disease
transmission between farms and landscapes• Banana stands in smallholder systems are perennial for
certain production systems, spanning over 5>150 years– Steady build up of pests and diseases, leading to
productivity declines
Systems Characteristics cont’d: Farm sizes
05
101520253035404550
>0-2 >2-4 >4-6 >6-8 >8-10 >10-15 >15-20 >20-40
Perc
enta
ge
AcresUganda Tanzania Kenya
Low input – Low output systems
BXW symptoms Foc Wilt Nematodes
BBTV
Black leaf streak
Weevil infestation
Banana Steak Virus?
Biotic stresses range from viruses, fungi, bacteria and nematodes to insects
Key pests and diseases cont’d
• In general highlands and sub-tropical regions have very less pest and disease pressure resulting into better productivity than in the equatorial humid lowlands;
• The equatorial belt has the highest pest and disease intensity which progressively reduces towards the subtropical regions;
• There is a need to systematically rank banana pests and diseases in Africa in order to guide research investment.
Suggested Ranking Criteria for pests and diseases in Africa
1. Number of countries affected. (Reference Gowen, 1995; Jones 2000; Blomme, et al, 2012)
2. Number of banana genotypes (Stover, 2000; Jones 2000; Blomme, 2012)
3. Yield loss attributed to each pest or disease ( Jones, 2000; Gold et al, 2001, )
4. Ease of control (Robinson, 1996; Gowen, 1995; Jones 2000)
5. Ease of eradication or probability of permanent control6. Estimated costs of control (High, medium, low?)7. Short-term impact on communities (high, medium, low?)8. Long-term impact on communities (high, medium, low?)
Staver (2000) Viljoen (2010) Blomme et al 2012
Black leaf spots (M.fijiensis & Cladosporium)
Xanthomonas Banana Weevil
Nematode Fusarium wilt Nematodes
Weevil Black leaf streak BBTD
Fusarium Nematodes BSV
Viruses Banana Weevil Mycosphaerellaleaf spots
Viruses Viruses Xanthomonas wilt
Fusarium
Key banana pests and diseases have not changed over the last decade
20
• Some diseases are spread by vectors over short and long distances accidentally and/or intentionally (BXW BBTD, BSV, etc)
• Most are moved in planting material in the informal seed systems (BBTV, BSV, BBrMV, CMV, BMMV, weevils, nematodes,Foc, BXW); ubiquitous plantings of bananas provide reservoirs of pests/diseases making it difficult to control
• Weak and/or non-existent quarantine services linked to lack of surveillance and limited information exchange within and between countries and regions.
• Limited capacity for efficient/effective pest and disease detection in support of quarantine
Risk 1. Potential for rapid dispersal by natural means
Region
Year
2009 2010
Africa 14.164 tonnes/ha 14.53 tonnes/ha
Eastern Africa 12.010 tonnes/ha 12.21 tonnes/ha
Middle Africa 16.290 tonnes/ha 16.30 tonnes/ha
Northern Africa 38.322 tonnes/ha 37.53 tonnes/ha
Southern Africa 44.557 tonnes/ha 44.81 tonnes/ha
Western Africa 17.183 tonnes/ha 19.33 tonnes/ha
A major yield gap exists especially in tropical Africa
FAO production data, 2012
Risk 2. Extensive yield losses threatening food security
1. Yield is a product of complex interactions between, the genotype, soil fertility, pests and diseases;
2. Methods are very variable, making comparisons difficult.
3. For some regions/countries, studies on yields attributed to pests and diseases are very limited
4. Nevertheless, pests and diseases probably contribute a significant proportion of the yield gap;
Risk 2. Extensive yield losses cont’d
Risk 3. Environment damage
• Use of chemical control is still limited in smallholder systems but may increase with changing farming objectives;
• Wide spread adoption of resistant varieties recommended to manage pests and diseases; but this may lead to monoculture and loss of diversity;
• Extensive rouging may lead to loss of associated biodiversity.
BXW management effects on environment
Parameter Macrofauna Mean number/trap/sample
Abundance Control (0 % rouged)
100%Rouged
Hymenoptera (ants) 20.2 14.6
Isoptera 11.8 6.2
Coleoptera 2.5 1.8
Orthoptera 1.4 1.1
Araneida 3.7 3.4
Others 5.4 3.2
Diversity Number of orders 24 15
100 % rouged
Control (0% rouged)
STRATEGY PRODUCTION SYSTEMS IN AFRICA REMARKS REFERENCE
1. Host plant resistance by convectional
EAHB & plantainIITA in Nigeria for plantains NARO/IITAin Uganda for EAHB; several varieties released in both regions
Tushemereirwe et al 2009
2. Host plant resistance by biotechnology
EAHB & plantain
IITA(NARO) has successfully transferred the sweet pepper gene against BXW; plants in CFT. More work in progress with cystatin genes against weevil borer in EAHB
Tripathi, 2011
3. Clean planting material linked to formal seed systems
EAHB, Plantain, cavendish
South Africa, Ivory cost, Ghana, Kenya driven y profit by tc companies; more informal systems linked to macro propagation in East and Central Africa. Quality control remains a challenge.
Viljoen, 2010
4. Cultural controls EAHB & Plantain in small holder systems
Systems dependent; affordable though labour intensive e g BXW Mgt in central Africa
Ssekiwoko 2010
5. Biological control All systems targeting weevils and FoC
No significant field application but may be applied as part overall IPM
6. IPDM All systems
Accepted by most as the way forward but information and technology gaps linked to weak policies constrainapplication.
Stover 2000; Viljoen 201; Blomme 2012.
MITIGATION STRATEGIES RECOMMENDED
What can and can not be done is influenced by a host of interactive factors:
• Limited collaboration within and between countries and regions, resulting in disfunctional management strategies and unchecked movement of pests and diseases across boundaries.
• The agro-ecologies, farming systems (cultivar sets in various food systems) and farming objectives, all influence management options and decisions
• Particularly in Africa smallholder systems dominate banana production and the socioeconomic setting; resources, labour, knowledge and information, infra-structure and local policy environment will interactively determine what can/can not be done.
• The agro-ecology in question and how the biophysical systems respond and/or impact on the crop and associated biodiversity