Authors: Bismark Kwesi Asitoakor*, Department of Crop Science, University of Ghana, Anders Ræbild, Department of Geosciences and Natural Resource Management, University of Copenhagen, Richard Asare, International Institute of Tropical Agriculture, Ghana, Philippe Vaast, Centre de coopération internationale en recherche agronomique pour le développement, Vincent Yaw Eziah, Department of Crop Science, University of Ghana, Andrew Gordon Howe, Department of Geosciences and Natural Resource Management, University of Copenhagen, Hans Peter Ravn, Department of Geosciences and Natural Resource Management. University of Copenhagen
Topics: Sustainability Science, Agricultural Geography, Environmental Science
Keywords: sustainability, pest and disease, shaded cocoa systems, climate change
Session Type: Virtual Paper
Start / End Time: 6:25 AM / 7:40 AM
Room: Virtual 14
Presentation File: No File Uploaded
On top of soil fertility and genotype influences on cocoa production, pests and diseases are major determinants of cocoa yields. Decades of pesticide applications to control these factors have undermined environmental integrity and increased production costs. Using eight commonly planted or retained forest tree species, as an aspect of integrated pest and disease management approach, we assessed the influence of shade tree species on mirid infestations and black pod disease in 10 cocoa farms in the Western region of Ghana. Occurrences of mirids were counted monthly for two years, as were the number of cocoa pods damaged by mirids and black pod disease. In addition, we measured temperature, rainfall, and relative air humidity on-farm. We applied logistic regression with nested random effects, and mixed effect models for determining variability in shade species influence on mirid population and damaged pods, respectively. Mirid populations varied between species and over time, with no consistent high and low periods. Two tree species, Triplochiton scleroxylon and Alstonia boonei, had highest and lowest mirid occurrences respectively in comparison with unshaded control plots. Pod damages due to mirids varied with time, season, and species contrary to pod damages from black pod disease that did not vary with species. Increases in temperature and low rainfall corresponded with elevated mirid populations and pod damages from mirid feeding but decreased black pod infestation on-farm. The selection of the right shade species could thus be an important factor and strategic tool in managing mirids and black pod disease in cocoa-agroforestry systems.