Influence of Climatic Parameters on the Incidence of Black Pod Rot of Cocoa Trees in Côte d’Ivoire

Abstract

Cocoa farming is very important to Côte d'Ivoire’s economy, however the increasing pressure of black pod rot is significantly reducing causing production, which is unfavorable to sustainable cocoa production. This disease is caused by Phytophthora palmivora, which is prevalent in all cocoa-producing areas. The objective is to determine the effect of climatic parameters on the incidence of the disease in the study localities. To achieve this, three plots were selected in each locality, based on the presence of black pod rot and the accessibility of the field. A 900 m2 was delimited in each plot, then 100 trees were randomly numbered to monitor the disease's evolution. Over seven months weekly counts of the number of pods affected and healthy pods was carried out for to assess the incidence of the disease in the different localities. Climatic parameters such as temperature, humidity and rainfall were recorded in each locality to determine their effects on black pod rot. The results showed a positive correlation between black pod rot rates and climatic parameters. Hierarchical ascending classification separated the localities into three groups, with Azaguié having the highest rate of black pod rot (34.78%) and the lowest rate of rot (6.59%) recorded in Loviguié. The study highlighted the threat posed by black pod rot to cocoa production in the Agnéby-Tiassa region, and the urgent need to develop sustainable control strategies.