Incidence and severity of coffee leaf rust and other coffee pests and diseases in Rwanda

Abstract

Coffee Leaf Rust (CLR) caused by Hemileia vastatrix Berk. and Br. has a worldwide distribution and causes enormous yield losses. A survey was conducted in Rwanda to evaluate incidence and severity of CLR and other coffee pests and diseases and to determine how the crop management contributes to CLR severity. A stratified random sample of 307 coffee farms was visited and the prevalence, incidence and severity were recorded. Results showed that all provinces were affected by CLR with the highest severity in Eastern province where the incidence was up to 100%. High altitudes were associated with low disease severity with a negative correlation of - 0.71. Coffee berry disease (CBD) was a minor disease but with a potential to become an epidemic in the future. Coffee leaf miner, Antestia bugs and Coffee stem borer were recorded but were managed below economic injury levels. All commercial cultivars were susceptible to CLR and most management practices such as mulching, pruning and fertilizer application were associated with lower levels of CLR severity except intercropping which resulted in higher disease intensity. Implications of this survey in relation to CLR management in Rwanda are discussed in this study.