Review of the regional dynamics and basic information on pests and diseases situations in Africa with special reference to CSSVD and Black pod disease

Transcription

1 Review of the regional dynamics and basic information on pests and diseases situations in Africa with special reference to CSSVD and Black pod disease George Ameyaw CRIG - TAFO Regional workshop on CFC/ICCO/COCOBOD Project on Integrated Management of Cocoa Pests and Pathogens in Africa, April, 2013

2 Introduction Cocoa pests and diseases are a major constraint to sustainable cocoa production. Risk of introduction of major cocoa pathogens and pests across the borders from different regions due to free movement of people and commodities

3 Cocoa diseases and pests are regional specific Witches Broom Frosty pod Black pod (Pm) Mirids Swollen shoot Cocoa pod borer VSD

4 This presentation is to provide a review of the dynamics of CSSVD and Black pod disease in West & Central Africa

5 CSSVD Cocoa Swollen Shoot Virus Disease First discovered in Ghana but now found in Côte d'ivoire, Togo, Nigeria but not reported in Cameroun?? (Stem die-back disease??) There is continuous spread within and between countries in the sub-region Effect of the virus is taking a heavy toll on production in the W/A sub-region

6 Cacao Swollen shoot disease Death of cocoa trees due to CSSV

7 Introduction of CSSV to West Africa End of 19th century Probable origin : host shift (s) from indigenous forest trees (alternative hosts) to cocoa (Sterculiaceae : Cola species (gigantia, chlamydantha, Bombaceae : Adansonia digitata -baobab-, Ceiba pentandra, baobab, sterculia tragacantha)

8 Baobab tree Ceiba pentandra Cola gigantea

9 Transmitted through the feeding activities of mealybug insects

10 CSSV epidemics within West Africa: Geographic and historical distribution of the disease In Ghana: the disease is found in all cocoa regions New outbreaks in the W/R Côte d Ivoire 1946 Nigéria Ghana Togo 1949 In Togo: the disease is in the south producing area (Kloto) until 2000, New outbreaks now in the main producing area (Litimé) In Côte d Ivoire: The disease was in the East until 2002 New outbreaks in the Central Region

11 Distribution of CSSV in Ghana

12 Distribution of CSSV in Côte d Ivoire outbreak areas Cocoa production area Economic Capital Political Capital New foci since 2002 Bouaflé Issia Sinfra Agnibilékrou Abengourou Adzope 150 samples Old foci 1940s?

13 Diversity of the virus in West Africa The virus is highly variable across locations (both within and between countries) Recent diversity study has categorised the viral strains into six distinct groups in Ghana, Togo and Cote D Ivoire Distinct species are noted to be within specific locations with some trans-border similarities

14 Origin of isolates: Ghana Côte d Ivoire Togo 93 CI CI CI CI CI77-09 NewJuab-00 Peki-00 91GHANA5-00 GHANA24-00 CI71-09 CI CI CI CI CI CI CI CI OBI2-04 OBI OBI2-10 OBI OBI1-10 DZO2-03 DZO4-04 DZO1-03 DZO3-04 ADO2-10 ADO1-10 DAN3-10 DAN4-10 OBK2-10 DAN1-04 DAN5-10 ABO4-10 CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI44-09 CI32-09 CI54-09 CI68-09 CI CI85-09 GHANA9-00 N1A-00 CI CI CI CI GHANA15-00 GHANA GHANA7-00 GHANA GHANA16-00 GHANA20-00 CI30-09 CI CI23-09 CI CI CI CI CI CI8-09 CI16-09 CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI TOV2-03 KEB10-05 AKP4-00 Agou1-93 KDA GAD5-05 NYO AHL4-00 Ghana30-00 AHL1-00 ITI1-04 KPM AHL14-05 AHL6-04 WOB12-02 WOB CI CI Maximum likelihood phylogeny, based on alignment of the first part of ORF3 Group B very common: Togo, Ghana and Côte d Ivoire Groups inter B-C 1, 2, 3, 4, 5,and 6 with high diversity Group C only in South of Togo Group A center of Togo + Ghana CI CI CI CI CI CI Group D center of Côte d Ivoire CI CI CI CI CI CI CI Group E East of Côte d Ivoire + Ghan CI CI CI CI CI CI GHANA26-00 Ghana9-10 Group G Ghana CI CiYMV Group F: East of Côte d Ivoire 98 Groups with different characteristics: very homogeneous (A, B et C) or with high diversity inside the group (D, groups inter B-C 3, 4, 6) Distinct groups or groups specific to certain areas

15 Management options Removal of infected trees and replanting with tolerant cocoa varieties Barrier cropping Resistant varieties being developed Mild strain cross protection being developed Vector control being developed

16 Black pod disease Several species of Phytophthoracause black pod disease Two main species in West and Central Africa are P. palmivora and P. megakarya P. megakaryais the predominant species in Cameroon. P. megakarya was reported in Ghana in 1985 and is still spreading in Ghana and Cote d Ivoire, Nigeria and Togo

17 Spread of P. megakarya in W. Africa 01/08/2013

18 Symptoms of Black pod disease Pathogen type: fungal, (Oomycete) Attacks Pod Pod rot Stem - Canker Leaf Leaf blight Root Root rot

19 Phytophthora pod rot

20 a b Phytophthora canker before scraping (a) and after scraping (b) Managed by exposing the lesion and applying any recommended fungicide on the exposed lesion

21 Leaf blight

22 Root rot

23 Management options Chemical control-fully adopted Cultural control Fully adopted Biological control Being developed Resistant materials- Being developed

24 Way forward for integrated control of diseases and pests Cultural Chemical Resistant Biological

25 Action points for effective management of endogenous diseases and pests in Africa Need to generate more information on the pathogens and pests e.g. yield loss estimates for the diseases/pests, effect of CODAPEC on black pod and mirid incidence in Ghana, etc Well informed stakeholders on diseases/pests in the sub-region Harmonise and co-ordinate activities to control and manage cocoa disease/pests regionally

26 Action points for effective management of endogenous diseases and pests in W/A Organise human/infrastructure/equipment resources for standard procedures/protocols (countries work together in a collaborative manner) Have a comprehensive regional emergency systems to deal with introduction of exogenous diseases/pests Strengthen international co-operation for strategic funding of key activities of scientists, training of quarantine and custom agents etc

27 Thank you

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