Agromorphological characteristics of Irvingia gabonensis (aubry-lecomte ex o'rorke) baill. (Wild mango) and Theobroma cacao L. in traditional agroforestry systems

Cocoa farming has grown exponentially, reaching over 4 million ha of cultivated land. The predominant expansion of cocoa farming from east to west has led to the degradation of the forest landscape. Today, the restoration of the environment and forest cover is a key issue for all agricultural development programs, including cocoa farming. Thus, the socially sustainable, acceptable and profitable ecological alternative to conventional cocoa farming remains agroforestry. This is a dynamic system of natural resource management based on ecological foundation that integrates trees into farms and thus makes it possible to diversify and maintain production. Agroforestry represents one of the most promising solutions for sustainably linking agricultural production and environmental protection. However, several unclear points remain regarding the choice of woody species and their ecological interaction with the cocoa tree. From a technical point of view, it is important to combine species that have favorable effects on the cocoa tree to ensure satisfactory agricultural production. This species is highly valued by farmers in western and south-western Côte d'Ivoire for food and trade. Its kernels are an important nutritional supplement (vitamins, fats, proteins, minerals), and their marketing provides rural populations with financial income. However, there is still a lack of knowledge about the characteristics of I.gabonensis and its interaction with cocoa. The study was initiated with a view to ensuring sustainable cocoa production. In Côte d'Ivoire, I.gabonensis is frequently grown in association with cocoa. The hypothesis behind this study is that the ecological interaction between I.gabonensis and the cocoa influences the agromorphological characteristics of the cocoa. Our study contributes to improve cocoa production systems for sustainable farming. More specifically, we aimed to describe the structural characteristics (height and diameter) of I.gabonensis, to assess its productivity and to describe its effect on agro-morphological characteristics of cocoa trees. To reach this goal, a design of 10 and 20 m radii was set up around the Irvingia gabonensis species, in which diameter, height, morphological characteristics of fruits and seeds, biomass and carbon stock were assessed. The results revealed a homogeneity of I. gabonensis morphological characters as well as fruit production, biomass and carbon stock in all localities, with the exception of height. The vigour and pod yield of cocoa trees in the vicinity of the species was reduced, given the low cocoa density observed in its surroundings. Its presence in cocoa plantations increases biomass production and carbon stock. I gabonensis stabilizes the rate of rotted and gnawed pods. I. gabonensis could therefore be integrated into agroforestry plots, provided that the cocoa density around it is reduced to minimize its impact on cocoa vigor and yield.