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 being “sent safely, in Wardian cases, to any country without removing the native earth from their roots.”35 By 1873 at the latest, Liberian coffee had been introduced in Ceylon.36 Coffee planters there hoped that the plant’s broad and thick leaves would be better able than arabica’s to resist attacks of the rust. In 1875–76, some coffee planters from Ceylon traveled directly to Liberia to observe how the coffee plant was being cultivated there, and to collect seeds for themselves. This movement of live plants, seeds, and soil in Wardian cases could have hastened the spread of the rust, although most commentators argue (compellingly) that any crop diseases carried in the cases would have likely made themselves apparent during the voyage itself.
Introducing the plant to Ceylon was just the beginning; farmers also had to determine how well it performed in the field. The initial trials were discouraging: “The Wardian cases had scarcely been opened,” noted one report, “when the Liberian plants were attacked by the prevalent plague, Hemileia vastatrix.” Undaunted, farmers continued to experiment with the plant and discovered that if the young plants were given proper care, “after 18 months or two years, they seem to be strong enough to withstand the disease and become healthy trees.”37 And even if Liberian coffee plants were susceptible to H. vastatrix, they suffered less than arabica. They were not defoliated to the same extent, and “the greater part of the leaf area is left intact and it is enabled in spite of the leaf disease to discharge its functions as an essential part in the economy of the plant.”38 By 1877, on some lowland coffee farms Liberian coffee produced as much as 2 tons per acre.
Even so, however, the crop faced other challenges. The fruit of Liberian coffee had a thicker skin than arabica coffee, so planters had to get special depulping machinery to process it. And there were also broader challenges with the market; Liberian beans had a different flavor from the arabica coffee that traders and consumers were then used to. The market for Liberian coffee remained uncertain through the 1870s, although global demand for coffee was expanding quickly enough that Liberian coffee usually found buyers.39 In the end, in spite of continued advocacy from its many boosters, Liberian coffee remained little more than an experimental crop. European planters and Sinhalese smallholders alike showed little interest in Liberian coffee. In 1878, at the height of the coffee boom, only about 440 acres of Liberian coffee were under cultivation in Ceylon.40
Still, in spite of the rust outbreak, owners of coffee estates remained generally optimistic about their crop through the 1870s. The outbreak coincided with a global spike in coffee prices after 1873, which for several years more than offset the losses in production. Between 1875 and 1881, the price for Ceylon plantation coffee fluctuated between 100 and 107 shillings per hundredweight, almost double what it had been a decade before. In 1877, the best year ever for Ceylon coffee planters, the total value of Ceylon plantation coffee exports exceeded £4,600,000. Profits increased even as production declined. In 1874, for example, when exports were 30 percent lower than they had been in 1870, the total value of coffee exports was 17 percent greater.41 “This great access of value to [one’s] returns,” wrote the Ferguson brothers, “more than sufficed to compensate the Ceylon planter for any diminution of his crop.”42 In fact, the high prices triggered a land rush; between 1869 and 1879—as the rust was wreaking havoc on coffee farms—some 100,000 acres of new coffee estates were brought into production, supported enthusiastically by Ceylon’s government. Even in the face of such losses, the planters continued to be optimistic. In short, as Thwaites observed, the planters were confident in the fact “there is little, if any, diminution in the anxiety to invest in the cultivation of coffee.”43
The New Botany and the Origins of Coffee Rust Science
Estate coffee remained profitable though the 1870s, but by the end of the decade, planters began to express some concern. Total production declined steadily during the trough years of each biennial cycle. The editors of Ceylon’s Planting Directory predicted (accurately) that the coffee harvest of 1878 would be “less by 40% than that of 1869, although the area cultivated has increased to nearly 100,000 acres since that time.”44
