or less normally (see fig. 1.3). But if the conditions favor the fungus, the leaf can develop many lesions, making it difficult for it to deliver nutrients to the plant. Badly infected leaves can drop off altogether. During severe outbreaks, trees can be defoliated, depriving the tree of vital nutrients. Branches fail to develop normally and die back. The fruit, likewise, may not develop properly, or at all (see fig. 1.4). Severe rust outbreaks cause significant losses during the current season (primary losses).
The most serious effects of the rust, however, are typically felt in later seasons (secondary losses). After an outbreak, the trees may seem to recover; the next season they produce a new flush of leaves, and to a casual observer all seems well. But damaged or dead branches can no longer produce fruit. A recent study of coffee diseases and pests in Central America found that primary losses could be as high as 26 percent, while secondary losses reached 38 percent.4 The rust exacerbated the patterns of biennial bearing; both the troughs and the peaks were lower. Once the fungus was present in the ecosystem, it was effectively impossible to eliminate. The coffee farm itself became a reservoir of infection. Farmers had to find ways of coexisting with the disease.
Picture a tropical mountainside, then divide it into three belts by altitude. The fungus is highly sensitive to temperature, and in the tropics, temperature is in turn heavily influenced by altitude. In the highest belt, temperatures are relatively cool. The rust fungus may be present but does not cause any significant damage to the plant. Coexistence is easy; farmers in this belt do not usually have to take any special measures to control the rust. Conversely, in the lowest and warmest belt coexistence is virtually impossible. The fungus flourishes and causes such extensive damage that farmers cannot produce the crop profitably. Yields are too low, or the costs of managing the disease are too high. Those farmers typically abandon coffee cultivation. Much of our story will focus on the middle belt, the space where coexistence is possible but requires effort. Here, the rust can cause significant damage, but coffee may still be profitable if farmers can manage it. The three belts lie on a continuum. The boundaries between them ebb and flow according to changing economic and ecological conditions. A sudden drop in the farm gate price of coffee, for example, may cause farmers to abandon expensive chemical control programs, which in turn would allow the disease to run its course. Conversely, a new rust-resistant coffee variety might make coffee production viable in a lowland region where the rust had previously made it impossible. Rising temperatures might trigger severe rust outbreaks in highland areas where they had previously been rare. The coffee ecosystems and the coffee economy—not to mention the rust fungus itself—are constantly changing, so coexistence with the rust is always provisional.
Figure 1.3. Coffee leaf with a few rust lesions, El Salvador. (Photo by author)
Figure 1.4. Branch of rust-infected coffee tree, showing malformed coffee cherries and dieback, Costa Rica. (Photo by author)
Themes
This story follows the global odyssey of the rust fungus from its home in the forests of southwestern Ethiopia, to its first spectacular outbreak in Ceylon, and then its spasmodic century-long journey across the global coffeelands. In each region, I move the focus outward from the fungus to consider how the coffee landscapes, societies, and economies shaped the rust outbreaks and the responses to them.5 Histories of tropical commodities typically focus on vertical linkages, which follow the commodity from plantation to cup, from producers in the Global South to consumers in the Global North. Here, I offer a horizontal approach to the history of commodities: the rust reveals the evolving—and deepening—connections among people and landscapes across the Global South. Just as global coffee markets became more tightly connected and interdependent over the nineteenth and twentieth centuries, so too did global coffee producers.6
This horizontal history of coffee reveals the complex connections between coffee’s life as a commodity and its life as a plant. The global coffee rust epidemic was triggered by a historically specific conjuncture of political, economic, social, technological, and environmental processes. It was, at first, a product of conquest, of empire, of liberalism, of steamships, and of migrations, both free and forced. These processes, among others, reconfigured the relations between H. vastatrix, the coffee plant, and the coffee landscapes in ways that favored a global epidemic. The coffee rust was not an isolated event; it was just one of a series of crop epidemics—commodity diseases—that started to break out at the same time, for many of the same reasons. The mosaic disease (a virus) wreaked havoc on global sugar production, while witches’ broom and monilia decimated cacao production in places. Banana growers grappled with new global diseases like fusarium and sigatoka. These diseases could be devastating; in Central America even the powerful United Fruit Company struggled to maintain banana production in the face of fusarium and sigatoka.7
Commodity diseases have, in places, changed the global dynamics of commodity production. Producers in disease-free regions often had a significant advantage over producers in diseased regions, who had to contend with declining yields and the financial and logistical burdens of disease control. Even before the rust broke out, coffee growers in Asia and the Pacific struggled to compete against Brazil, whose coffeelands outproduced everyone else’s. The rust outbreak simply helped consolidate Brazil’s advantage. But the larger history of the rust also suggests that such regional advantages are temporary. Over time, the rust made its way around the world. Other significant diseases and pests, driven by the same forces as the rust, followed. The coffee berry borer (known as the broca in Spanish and Portuguese) traveled across the South Atlantic from Africa to Brazil in the 1920s and, since the 1970s, has spread through Central America. As coffee cultivation continues, farmers have to grapple with an accumulating array of local and global diseases and pests. Like the Red Queen in Through the Looking Glass, coffee farmers must run faster and faster just to stay in place.8
Coffee farmers—from smallholders to owners of estates—have never simply been passive victims of the disease. From the beginning, they innovated creatively and continuously in their quest to control the rust. They discovered and propagated rust-tolerant or rust-resistant coffees, some of which scientists would later use as stock for breeding programs. Well-heeled farmers bought exotic coffees at tropical nurseries in Europe’s capital cities; some enterprising planters even organized collecting expeditions of their own. They experimented with virtually every chemical known or suspected to control crop diseases. They manured their farms and—depending on their situation and their particular understanding of the disease—they increased or reduced the amount of shade. They debated the causes of the rust; in Ceylon, the farmers who practiced what they called “high cultivation” blamed other farmers for the devastation caused by the rust. In Africa, European settlers sometimes blamed African farmers for infecting their farms with the rust. Debates about rust control have always been embedded in broader, intensely moralistic debates about good farming practices. Both individually and collectively, farmers searched for explanations for the outbreak and for strategies to coexist with it. Now, as then, farmers adopted whatever control methods best suited their particular situations, both economic and ecological.
Some places gradually developed administrative and scientific infrastructures to coordinate collective responses to the rust. Before World War II, these included imperial and colonial botanical gardens, ministries of agriculture, and national coffee institutes. After the war, this infrastructure grew to include multilateral research organizations—especially Portugal’s Coffee Rust Research Centre (CIFC), bilateral and multilateral development organizations such as the US Agency for International Development (USAID), nongovernmental organizations, and private corporations. From the very beginning, these institutions have operated as an informal and decentralized yet powerful research network. Experts across the global coffeelands have constantly
