Epidemics and the future of coffee production

Abstract

In this perspective, we draw on recent scientific research on the coffee leaf rust (CLR) epidemic that severely impacted several countries across Latin America and the Caribbean over the last decade, to explore how the socioeconomic impacts from COVID-19 could lead to the reemergence of another rust epidemic. We describe how past CLR outbreaks have been linked to reduced crop care and investment in coffee farms, as evidenced in the years following the 2008 global financial crisis. We discuss relationships between CLR incidence, farmer-scale agricultural practices, and economic signals transferred through global and local effects. We contextualize how current COVID-19 impacts on labor, unemployment, stay-at-home orders, and international border policies could affect farmer investments in coffee plants and in turn create conditions favorable for future shocks. We conclude by arguing that COVID-19’s socioeconomic disruptions are likely to drive the coffee industry into another severe production crisis. While this argument illustrates the vulnerabilities that come from a globalized coffee system, it also highlights the necessity of ensuring the well-being of all. By increasing investments in coffee institutions and paying smallholders more, we can create a fairer and healthier system that is more resilient to future social-ecological shocks.

An Overview of the Mechanisms Involved in Coffee-Hemileia vastatrix Interactions: Plant and Pathogen Perspectives

“…The development of the entire uredinial cycle depends on environmental conditions [7,18]. Urediniospore germination requires water and is optimal at about 24 • C; rain is the primary dispersal mechanism for spores.…”

“…It has been associated with changes in climatic conditions, the ecology of coffee farms, and recurring economic shocks [15,16]. Initially, there was some speculation that the epidemic might have been caused by the emergence of new, more aggressive rust races, but this hypothesis has not yet been confirmed [16,18].…”

“…vastatrix infects the lower surface of the leaves where it produces chlorotic spots preceding the differentiation of suprastomatal, bouquet-shaped, orange-coloured uredinia, leading to premature defoliation (Figure 1). According to Rhiney et al [18], defoliation is CLR's main effect, which reduces the plants' photosynthetic activity affecting the quantity of fruits and can influence coffee quality.…”

“…Nevertheless, to improve the efficiency of the breeding process it is crucial to deepen our understanding of the complex mechanisms involved in the plant-pathogen interactions. According to Rhiney et al [18], defoliation is CLR's main effect, which reduces the plants' photosynthetic activity affecting the quantity of fruits and can influence coffee quality.…”

Coffee Leaf Rust (Hemileia vastatrix) from the Recent Invasion into Hawaii Shares a Genotypic Relationship with Latin American Populations

“…Although CLR disease is not generally fatal to coffee plants, it can affect the growth and fruiting ability [6], causing annual losses exceeding USD two billion [3]. CLR is notorious for its ability to break down host resistance [7][8][9], which can result in huge socio-economic impacts in affected regions [10].…”