IUFRO International Conference 15 -17 October 2008 Accra

IUFRO International Conference, 15 -17 October 2008, Accra Ghana Theme: Traditional Forest-related Knowledge and Sustainable Forest Management in Africa Smallholder cocoa agrorest, traditional knowledge and pest and diseases management in Southern Cameroon. Denis J. Sonwa 1, Stephan F. Weise 2, Ousmane Coulibaly 3 1. Center for International Forestry Research (CIFOR), Po Box 2008 (Messa) Yaoundé-Cameroon, Email: dsonwa@cgiar. org or desonwa@yahoo. com 2. International Institute of Tropical Agriculture (IITA)- Ghana 3. International Institute of Tropical Agriculture, Plant health Management Division, P. O. Box 08 -0932, Cotonou, Benin

Presentation outline (1) Importance of the cocoa agroforestry system, (2) Pest constraints & management (3)Micro-Ecology of cocoa agroforest and pest management (4) Indigenous pest management developed by farmers (5) Perspectives

(1) Importance of the cocoa agroforestry system The cocoa tree originated from Amazon forest with different managements options in West and Central Africa Low/no-shade, quasi-monospecific (Western Ivory Coast) Disappearance of forests’ functions Management of cocoa 15 -20 years of sustained production Shaded, multistrata, multispecies (Southern Cameroon) Limited modification of forests’ functions Co-management of cocoa & retained/introduced trees More than 40 years of sustained production

(1) Importance of the cocoa agroforestry system The study area: Southern Cameroon Yaoundé Ebolowa 80 3. 9 25 Population Density (Persons/Km 2) Fallow length (years) Forest (% land)* Mbalmayo 10 - 41 5. 4 39 5 7. 5 59 Source: Gockowski (1996), *Thenkbail (1999) 914 km 574 km YAOUNDE MBALMAYO Humid Forest Zone [21. 7 million ha] THE BENCHMARK [1. 54 million ha] EBOLOWA

(2) Pest constraints & management Table: Mean severity rating of identified cocoa production constraints in Southern Cameroon Constraints Mean Severity Rating by Constraint by Block Yaoundé (n=96) Black pod disease 2. 7 Capsids Mammals Minor pests/diseases Other constraints Mbalmayo (n=105) 3. 7 Ebolowa (n=99) 4. 1 HFZ Mean (n=300) 3. 5 3. 6 0. 7 2. 1 2. 9 0. 6 1. 6 2. 8 0. 9 2. 4 3. 1 0. 7 2. 0 2. 4 2. 3 1. 5 2. 1 Sonwa et al. (2005) Main fungicide uses by farmers: Nordox, Kocide, Cacaobre, and Ridomil (Mainly copper-based ) Few insecticides uses by farmers: Azinphos methyl, Cypercal, Dusban and Aldrin (a WHO 1 b classification: “highly dangerous”)

(2) Pest constraints & management The two main constraints faced by those who use pesticides (i. e. 60% of farmers) are the high cost and unavailability Table: Shopping preferences of farmers according to pesticide supply points in each of 3 humid forest zone of southern Cameroon (in % households per zone) Yaounde (n=96) Mbalmayo (n=104) Ebolowa (n=100) HFZ (n=300) P Buy their pesticides in the village market 23 ab 29 a 10 b 21 0. 1206 Buy their pesticides in the nearest town Buy their pesticides in a local cooperative 34 a 0 b 10 b 0 b 16 b 3 a 20 1 0. 0066 0. 0277 Buy from other farmers Take on credit from a local company Others. 0 0 0 b 1 1 20 a 4 0 21 a 2 0 14 0. 2017 0. 3874 0. 0505 Sonwa et al. (2008) The consequence is non/less application of pesticides which generally leads to significant cocoa yield losses

(3) Micro-Ecology of cocoa agroforest and pest management Forest cover influences light intensity, temperature, air movement, and the relative humidity within plantations Fast spread of the black pod disease often associated with high levels of crown closure Fast spread of the capsid often associated with low levels of crown closure Some tree species typically associated with the cocoa plantation, host the Phytophtora fungus or Miridae spp Pests and diseases are generally influenced by the presence of trees within the cocoa production system

(4) Indigenous pest management developed by farmers Coulibaly et al. 2002 Sustainability of the use of Cannabis plant extract is however threatened as the plant is officially forbidden for cropping because of its classification as drug

(4) Indigenous pest management developed by farmers Coulibaly et al. 2002 Plant-based pesticide species are directly found within the cocoa plantations, thus making them accessible

(4) Indigenous pest management developed by farmers Coulibaly et al. 2002 The uses of these plants extract are based on the previous farmers knowledge on their toxicity (some are poisons, while others are used for human heath purpose) The application of the new mixtures is combining with the former knowledge of farmer to manage tree density inside cocoa plantations

Perspectives Most fruit & non-fruit trees species commonly planted by cocoa farmers inside their cocoa plantation(southern Cameroon ) Fruit trees species (% of farmers) (83 ) Non fruit trees species (% of farmers) 1 Dacryodes edulis Terminalia superba (32) 2 Persea Americana (77 ) Triplochiton scleroxylon (31) 3 Mangifera indica (71 ) Millicia excelsa (25 ) 4 5 Citrus sinensis Citrus reticula (57 ) (27) Ceiba pentandra Ficus mucuso (18 ) (14 ) Sonwa (2004) Introducing/maintaining/managing trees inside cocoa agroforest generally increase the socio-economic and ecological importance of cocoa agroforestry system

Perspectives Challenge: Managing pest and diseases constraints in a complex cocoa agroforest Previous efforts were generally cocoa production oriented There is a need of tradeoffs between forest cover and the constraints imposed by pests and disease on sustainable cocoa production.

Perspectives Ongoing fields activity on cocoa agroforest management in Cameroon Participatory discussions between farmers to improve their cocoa agroforest models Farmers fields school activities (IPM) Multidisciplinary approaches taking in consideration farmer experiences/knowledge are keys for Sustainable tree forest management in cocoa landscape in Cameroon

Conclusion The indigenous knowledge developed by farmers to overcome pest and disease problems are based on single plant extract or mixture (sometime with synthetic pesticides). The knowledge developed by farmers are based on their previous perception of the nature of the products they uses. The methods are also taking in consideration previous knowledge of farmers related to the management of tree density to reduce pest and diseases Sustainable forest management can not omitted to take in consideration forest trees use by farmers to manage pest and diseases in cocoa farms…. These trees also play socio-economic and ecological roles in cocoa landscape

Many Thanks