Planters did recognize a correlation between the fungus and the drops in production but did not necessarily see the fungus as the cause. Rather, they argued that the fungus and the drop in production were both the consequences of a deeper disease inside the plant. “The leaf disease is not the ‘disease’ but an effect arising upon and from a diseased condition already contracted by the coffee trees,” argued one planter. “Fungus, blight, mouldiness, appear only upon already diseased subjects. Wherefore surely we are less concerned as to inquiring into how the evil operates … than in ascertaining the cause of it.”26 The planters had no single theory to explain the disease; most invoked some sort of physiological or environmental explanation. Some argued that the disease was caused by a “poisoning of the juices” of the coffee tree. They suggested that the disease was the result of poor cultivation, inadequate manuring, or climatic disturbances. Some planters argued that the disease was just temporary and that sooner or later it would “wear itself out,” as earlier outbreaks of diseases and pests appear to have done.27 In the end, planters were primarily interested in finding a practical way to manage the disease, however it was caused.
Managing the Coffee Rust
Farmers fought back against the rust, both individually and collectively. Some planters thought that high cultivation could help control the rust and perhaps even cure it. High cultivation involved a holistic approach to farming. The planter Edmund Hull succinctly described it as “careful pruning, manuring, shade, where required, the entire suppression of weeds, [etc.].” He found “a great unanimity of opinion” among planters, who agreed that while the coffee rust might not be “altogether prevented by high cultivation, [the disease] may be at least checked by it.”28 The discourse of high cultivation had a strong moral undercurrent. Some European farmers used the concept to distinguish their farming practices from those of the—supposedly inferior—local farmers. In this view, any planter who failed to practice high cultivation, who neglected his farm, was letting his peers down—and also allowing the disease to spread.
Estate farmers tried a range of solutions, many of which drew on ideas and technologies imported from abroad. For example, one key component of high cultivation was manuring—the use of fertilizers. Coffee planters in Ceylon had been interested in fertilizers even before the coffee rust broke out. This was one area in which the planters had learned from scientific innovations and adopted science into their farming practice. The German chemist Justus von Liebig had revolutionized the fertilizer industry in the 1820s and 1830s. Liebig, a professor of chemistry at the University of Giessen, had developed the field of agricultural chemistry. His laboratory produced the earliest chemical fertilizers. Still, the scientists did not have a monopoly on the study of manures, and coffee planters used chemical and organic, local and imported fertilizers alike, choosing whichever they thought would work best. Ceylon planters, for example, used cattle dung, pig dung, dead animals, bones, castor-oil cake, and wood ashes (among others) as fertilizers, in addition to the chemical fertilizers then gaining prominence. Imported fertilizers were clearly important: between 1874 and 1877—as the rust made serious inroads into coffee production—the value of fertilizer imports to Ceylon quadrupled.29
In the early years of the outbreak, it seemed that manuring did mitigate the coffee rust, if not cure it outright. Coffee growers who applied manure to their farms found that coffee yields recovered, at least partially. They concluded, therefore, that the crop losses were caused by soil exhaustion and that manuring could cure it. Thwaites, for example, claimed that “high cultivation, with judicious manuring, enables the tree to better sustain the attacks of the fungus, and to retain strength and vigour enough to produce a fair yield of berry.” But he worried—correctly, as it turned out—that the manure might not be a permanent cure for the disease.30 Recent research has shown that the relationship between manuring and the epidemic is complicated. While manuring can offset some of the losses from the rust, its effectiveness depends on which fertilizers are used, how often they are applied, and the broader structure of the farm.31
Other planters experimented with chemical sprays. They used ideas and technologies imported from Europe. In his initial publication on the coffee rust, Miles Berkeley recommended that planters use sulfur, then the most widely used fungicide, to control the rust. Sulfur—in various compounds—had been used as a fungicide in Europe since the early nineteenth century. Farmers had used it to control mildew on grape vines and fruit trees, so it seemed reasonable to assume that it could also control the leaf rust. Sulfur sprays functioned primarily as preventives rather than curatives. Properly applied, they could prevent spores from germinating but could not cure a plant that was already infected. Berkeley recommended that farmers spray the coffee plants or use syringes to apply the sulfur directly to the infected parts of the leaves. It proved to be difficult, however, to use this imported technology to control the rust. To be effective, sulfur had to be applied at the specific moment the rust was germinating, and scientists had not yet established when this moment occurred. The rust’s life cycle had not yet been worked out. A second challenge was physical: Berkeley noted that the disease would be difficult to control since “the fungus is confined to the underside of the leaves, and the mycelium is not superficial.”32 This meant that the fungicide would have to be sprayed upward to be effective. Finally, fungicides were also expensive; they required significant investments in labor, chemicals, and equipment.
Farmers and researchers alike began searching for rust-resistant arabicas. They imported coffee plants from around the globe, through public and private institutional networks. The Royal Botanic Gardens at Kew helped facilitate a number of these global transfers, as they did with other crops such as tea, cinchona, and rubber.33 Private institutions and individual planters also moved live planting material over great distances, often with unprecedented speed. Coffee planters could purchase coffee seeds and plants from newly established British nurseries that specialized in exotic crops, such as William Bull in London and Veitch in Liverpool. Some planters conducted bioprospecting expeditions of their own. The many non-Europeans who traveled to Ceylon as laborers, traders, or migrants of other sorts may have also circulated their own planting materials, as they had done for centuries before the age of European hegemony. Unfortunately, the surviving documents remain frustratingly vague about this possibility. In the end, however, all the imported arabicas promptly succumbed to the rust.34
For the first time, coffee farmers also tried to cultivate other plants of the Coffea genus. In the early 1870s, some planters experimented with Liberian coffee, a coffee species native to West Africa. Unlike arabica coffee, Liberian coffee was a lowland plant, better adapted to warm and humid temperatures. The first seeds and seedlings of Liberian coffee were shipped to Kew and to William Bull’s nursery in 1872. From there, the plant was disseminated around the world through parallel state and commercial networks. By the mid-1870s, Liberian coffee plants were